Inland Transit/Inland
Inland Transit.
The usefulness of railroads is now admitted by all classes of the people; and the beneficial results have been apparent to the landowner, cultivator, and trader, wherever they have been established. The construction of railroads, like other things, requires experience, practice, and reflection. The railroads that have been constructed, have not been executed upon the best model or form that might have been adopted, although designed by engineers of great talent, taste, and powers of mind; and nothing but practical experience could have shown the results now obtained. The Manchester and Liverpool railroad, in my opinion, is constructed too narrow both in the trams and the space between them, and the sharp curvations in that road should be avoided, if possible, as well as the sedant inclined planes: the level on the line should be divided as equal as possible in the distance.
The curvation produces considerable friction on the flanches of the wheels, which impedes the velocity of the carriage, as well as the uphill, and strains the action of the machinery, and causes a considerable additional consumption of fuel by the delay.
The Darlington and Stockton railway is about forty miles in length, and has been in work eight years. It was first constructed in a single tram or line of rails ; but the directors soon found that a single line of road was not sufficient to transport their increasing trade. They have lately added double trams or lines of road, with a number of inlets and outlets on each side of the line, by which they have now avoided all obstructions.
I would respectfully call the attention of the reader and the public to the reports and evidence of the directors of the above railroads, given in evidence on the London and Birmingham Railroad Bill, in the last session of Parliament, which will be found herein, with the estimates of expense, revenue, and proceedings on that interesting and important incorporation, as well as the advantages of the Liverpool and Manchester railroad; also the Darlington and Stockton, with their respective expense, revenue, and benefit.
There are seven other railroads now projected; viz. 1st, the London, and Birmingham, and Liverpool, called the Midland railway; 2d, the London and Greenwich, which has been since designed to Dover, now called the Eastern railway; 3d, the London and Southampton railway; 4th, the London, Bath, and Bristol, called the Great Western railway; 5th, the London and Brighton railway; 6th, the Grand Southern railway, from London to Horsham, Arundel, Portsmouth, and Southampton, and from Horsham to Shoreham and Brighton; 7th, the Grand Northern railway, from London to York, with several branches to Norwich, Nottingham, Sheffield, Leeds, Hull, &c.
There are two or three other projects in contemplation; a branch from the Western to the town of Windsor, and another in Leicestershire.
1st,—The London and Birmingham Railroad Company was incorporated in the last session of Parliament. This design, will, no doubt, prove a great national benefit; it will give extensive and lasting advantages to the landowners, farmers, graziers, manufacturers, mineralogists, and merchants in the midland counties, and the metropolis.
This line of country is not very favourable for such a work: the distance on the line from London to Birmingham is 112 miles, and Birmingham is situated about 365 feet above London, and the highest summit on the line is 418 feet, at Tring, 30 miles from London.
The greatest rise is about 16 feet per mile, in several parts of the line. The railroad will be constructed with 10 tunnels. The first tunnel will be 2 miles from London; the second at Harrow Weald, 13½ miles; the third at Watford; the fourth near Tring, 30 miles; the fifth at Leighton Buzzard; the sixth, seventh, and eighth, at Weedon; the ninth at Kilsby; and the tenth at Berkswell,—making together about 8 miles of tunnel on this line;
| Width of railway on embankments | 28 feet | |
| Viz.—Double lines of rails, each line being five feet wide | 10 | |
| Space between the two lines | 6 | |
| Space outside the lines, 6 feet on each side | 12 | |
| 28 | ||
| Width on the cuttings One foot additional being allowed on each side for a drain. |
30 |
This line of railroad may be considered perfectly practicable; but, owing to the general rise and fall of the country, as appears by the section of the projected railroad, with 10 tunnels, must necessarily be expensive in its construction and maintenance in repairs, lighting the tunnels, and attendants; although I believe that Messrs. Stephenson, the engineers, have selected the best line of country between London and Birmingham for the design.
Unless they had taken the line by Oxford, Tame, and thence between Warwick and Stratford-upon-Avon, to Birmingham. This line may be two or three miles longer in point of distance, but would avoid the tunneling, and a better level and under strata would be found; as well as the traffic in coaching, &c. from the West of England, Cheltenham, Gloucester, Worcester, Kidderminster, Tewkesbury, Stratford, Warwick, and Oxford, at a considerable less expense.
The estimated expense is 2,205,352l., and the annual revenue, when completed, is 793,407l. This may appear, to some, a considerable outlay of capital; but I respectfully submit, that it will prove one of the most beneficial designs ever projected in England. It opens a grand, safe, and expeditious line of transit through the midland country, by which science, manual labour, agriculture, manufactures and commerce, will be extended beyond the power of man to contemplate, and a flood of prosperity will return, hitherto unknown to civilised man.
2d.—The London and Greenwich Railway Company was incorporated by act of Parliament, on the 17th May, 1833. Distance of this line is about 3¾ miles on a tide level ; estimated expense is 400,000l.; the annual revenue about 105,550/.; and the expense of conducting, wear and tear, &c. of the railroad, is 23,550l. per year. It may be considered that the London and Greenwich railway is only the commencement of the Great Eastern railway to Dover. This design is novel; it is proposed to be constructed upon arches about twenty feet high, from London Bridge to Greenwich, on a tide level the whole of the way; designed by George Landman, Esq. the engineer, who has laboured hard with Mr. Walters, the secretary, whose conduct deserves public thanks. The engineer, no doubt, has reflected well upon the cause and effect of his design: the design upon arches must be considered a very considerable additional expense, and this estimate cannot be taken as an average expense of railroad; the average expense of railroads is within 8000l, to 10,000l, per mile on the level. This line of railroad is intended to pass His Majesty's arsenal at Woolwich, and from thence to Gravesend, and to cross the river Medway below Chatham, and thence to Dover, with a branch by Eltham to the vale of the Medway, to Tunbridge and Maidstone, which can be constructed without a tunnel. I feel confident that the line over the river Medway below Chatham is objectionable, inasmuch as the Government will not consent to a bridge being; thrown across that river below Chatham. The line by Eltham, Riverhead, Maidstone, to Dover, is about seventy-nine miles in distance, and a much better line of country, and will prove a lasting benefit to the landowners, cultivators, farmers, and hop-growers of Kent: it will enable them and travellers to execute their respective interests, without any delay, at one half of their former expenses.
3d.—The railroad is designed by Francis Giles, Esq., civil engineer, from London to Southampton. Distance of this line is within eighty miles; and the engineer's estimate expense, 1,000,000l.; and the probable revenue is estimated, when completed, at 374,451l. 8s. 6d. per annum; and the annual expense of repairs for conducting the railroad at 56,000l. The line is from Lambeth, and to pass by Kingston, Weybridge, Basingstoke, and Winchester, to Southampton; the levels of that line of country are not favourable for a railroad; the summit level is 380 feet above London. This inclined plane rises twenty-two feet per mile, for about eleven miles on the line. I consider that Mr. Giles has selected the best line between London and Basnigstoke; and is exceedingly wise in not recommending a tunnel through the long summit between Basingstoke and Winchester, of nineteen miles; and the line appears to me, without a tunnel, impracticable. According to the law of railroads, as will be found in theory and practice, no railroad for despatch of business, speed, and safety, should rise more than from twelve to fourteen feet per mile. The law of gravity, propulsion, and speed, will be found to be obstructed about one hour in every two feet rise, in twenty miles; so that the speed of a steam engine that could perform thirty miles an hour on the level, will be reduced to less than five miles per hour, upon a rise of twenty feet per mile. And the Great Western Railway is proposed to pass almost parallel with the Southampton, from London to Basingstoke, Reading, and Newbury, would reduce the estimated traffic on the Southampton line considerably. And it appears, by the estimate of traffic, that the revenue chiefly depends upon the coach trade on the line to Basingstoke. Southampton is a beautiful town, and a place more for fashion than trade, and this line can never be made a line of despatch or speed, owing to the rapid rise and fall of the country; consequently, the Southampton railroad cannot be considered a national object.
The 4th railroad in progression is the Grand Western Line, between London, Bath, and Bristol; the line of distance is about 122 miles. This line of country is very favourable for a railway, about sixty miles on the line from London. This great national work is projected by Mr. J. E. Brunel, who is the engineer to the company, and who has investigated that line of country; and I feel no doubt, from Mr. Brunel's activity and talent, that he has selected the best line for the purpose that can be found. But the billy country for twenty miles to the east of Bath, which is from 700 to 1000 feet high above the level of Bath, forms almost an insurmountable barrier to a railroad.
Mr. Brunel proposes a tunnel through those hills whose under strata is composed of chalk and freestone of easy and safe cutting. But there are decided objections to tunneling for railroads at the depth and length here required. First, the tunnel must be many miles long, without light and air, except artificial air and light, perhaps gas lights. The want of atmospheric air, combined with the combustion of gas, smoke, and steam, will render the tunnel almost incapable of human existence. And, secondly, the condensed or compressed air in the tunnel, if it is only a mile long, will give a formidable resistance to the speed of the propelling engine and train of carriages, that would require more than double the power to propel them, compared with the power on the same level in the open air; and if a carriage enter at the other end at the same time, it will act like two balls in a tube[1], the one would repel the other. Thirdly, in driving a tunnel, of the presumed depth of only 600 or 700 feet below the surface of that country, is considerably below the level of several great springs, that form the head of the rivers Isis, the Kennet, and the Avon; and cutting across the country by the projected tunnel would, no doubt, tap these powerful springs, which would drain all the high country, and convert the projected tunnel into a river.
The line from Bath to Bristol is about twelve miles in length, and may be considered almost tide level; and that part of the design may be easily executed, at a moderate expense. Both stone and iron, in abundance, is at hand; two of the chief materials for constructing railroads. This work, if executed, would confer a lasting benefit on the country. The engineer's estimated expense is 2,550,3001., and revenue about 747,752l. 11s.
5th. There are two projected lines from London to Brighton and Shoreham. The first line from London, Croydon, Mersham, St. Leonard's, to Shoreham and Brighton, is about fifty-four miles on the line of distance projected by Mr. Vingnolds, civil engineer, and designed to commence from the Elephant and Castle, Newington, and to run from thence to Norwood and Croydon. Merstham and St. Leonard's Forest, to Shoreham and Brighton. In the above line. Mr. Vingnolds has designed two tunnels; the first tunnel is intended to pass under the Beulah Spa, from Norwood to Croydon, about two miles and a half. The summit at Croydon will be 170 feet above the tide at London Bridge, and will rise from Croydon, about twenty feet per mile, to Merstham summit. Merstham summit will be 360 feet above the tide; and another tunnel to pass into the vale of the Mole, thence by the County Oak, to St. Breval's and St. Leonard's Forest and Bramber, to Shoreham and Brighton. There are three decided objections in constructing a railroad on this line: first, a railroad could be carried from London to Croydon, by Tooting and Mitcham Commons, on an easy inclined plane, without a tunnel; secondly, a tunnel under the Beulah Spa will drain away all the water in that district, and the same will happen at Merstham; and, thirdly, the high elevation of the two summits at Merstham and St. Breval's Forest, with the rapid falls on the line, would render a railroad useless, as to speed and carriage of heavy loads, with very considerable extra cutting on the line.
The second line is from London to Brighton and Shoreham, projected by Messrs. Rennie, civil engineers, to commence at Kensington Common, and run from thence to Tooting and Mitcham Commons, to Carshalton; thence between Merstham and Reigate, by Horley, and Crawley, and Hand Cross, to Brighton; and from Brighton to Shoreham. The summit of this line is about 500 feet above the tide at London Bridge. Distance on the line about fifty miles to Brighton, and six to Shoreham, making together fifty-six miles. The first ten miles is an excellent progressive level, and firm ground; but the rise and fall of that line of country from Carshalton to Brighton appear to be impracticable for the construction of a railroad, for travelling or the carrying of goods, or any other useful purpose, which I understand Messrs. Rennie purpose to obviate, by constructing four tunnels under the four high summits, on their projected line, to save distance, and the passing over hills from 700 to 800 feet high; by their section, the length of tunnels together will be about ten miles on the line to be cut throughout, an under strata of chalk, freestone, loam, clay, sandstone, and gravel, in some places, 200 to 300 feet below the surface of the country, besides considerable extra cutting on the line, and the enormous expense of the tunnels. The tunneling would, no doubt, tap the Great Surrey and Sussex springs, which rise above the level of the projected tunnels, which springs form the heads of the rivers Mole, Wey, Arran, Adur, Medway, and Derwent. All these rivers take their course near, or immediately in the line of the projected railway; and it is more than probable that by tapping these springs, the line of railway would become converted into a river to Brighton, and that the uplands would be drained of their waters, by tapping the springs below.
These waters pass through veins in the earth, both on high ground and low levels, like the construction of the veins in the human body; and all practical men know, that if a vein or artery is opened in the foot, it will let out all the blood in the head; and if there were no other reason, the tunneling for so long a distance, with the obstruction of the air in the tunnel, and the combustion of gas, steam, smoke, and sulphur, renders, in my opinion, this design impracticable. The expense is estimated at 850,000l., and the revenue about 130,000l. per annum. It also appears by the law of gravity and propelling power of a movable steam engine, the rise, and long progressive inclined planes here designed, no travelling engine would exceed the speed of the present Brighton coaches; and questionable, from the experiments made on the Manchester and Liverpool railroad, that an engine, with travelling machinery, could be constructed to go up hill, twenty-five feet per mile, at the speed of five miles an hour, as I shall hereafter refer to the respective experiments tried on a railroad, and the comparative speed on the level, the progressive rise, or up hill and down hill, with its several effects, loads, delays, and advantages.
I feel no doubt but Messrs. Rennie have, long since, reflected upon all the above consequences; but I, with great respect, venture, for the public good, to differ in opinion with them on the line and construction of their projected railway; and more particularly so, when they know that there is a line of country about the same distance with practicable levels, and that a railroad can be constructed from London, to Shoreham and Brighton, without a tunnel. They have given notice to Parliament, and Parliament will investigate the merits of all the above projects.
6th—Is the Grand Southern railway, projected by myself. I now consider that the science of constructing railroads with the aid of locomotive engines, has already outstripped both the speed and national utility of canals; and having the knowledge of the line of country between London and Portsmouth and Brighton, from my former surveys in the grand ship canal to Portsmouth. I, in September, announced my intention to lay a plan before the public, of a railroad between London and Horsham and Portsmouth, with a branch from Horsham, to Shoreham and Brighton; finding that line of country, from its levels, well calculated for a railroad, there being but two summits over which the line would have to pass, at Epsom Common, 150 feet, and the other on the Holm Wood, 200 feet above the tide at London Bridge, and on this line no tunneling would be required; see plan and section. The utility of this design is too apparent to require a long comment, and would avoid the objections of the two other projected lines, both as to tunnels, levels, and draining the upland country of all its water; while it would give to the landowner, trader, traveller, merchant, and Government, the advantages of proximity of the whole southern coast, to the metropolis, in time of war or peace, by the speed and safety of a well-constructed railroad, without delay or danger. My estimate of this great work is about 1,500,0001, and revenue about 500,000l. per annum when completed.
As this work is of great national importance. I have not thought it right to press the subject now, but shall wait another session of Parliament, with all its details, &c. &c.
With the view of accomplishing this desirable object, the direct line of country has been surveyed, and found so favourable, that but little extra cutting would be required, about 150 miles of the distance (which is within 190 miles) being nearly tide level.
It is proposed to commence the projected railroad at Kingsland, near Shoreditch, and to run thence by Tottenham and Waltham to Bishop's Stortford (with short branches to Hertford and Ware), to proceed from Bishop's Stortford by Saffron Walden and Linton to Cambridge, Peterborough, Stamford, Grantham, Newark, Lincoln, Gainsborough, and Snaith, meeting the Leeds railroad at Selby, and thence to York, with a branch from Cambridge by Newmarket, Bury, and Thetford to Norwich, distant about sixty miles.
This work, when accomplished, will immediately give to the great northern agricultural and manufacturing counties all the advantages of proximity to the metropolis, by the speedy transit of a railroad.
The advantages of railroads were proved in the last session of Parliament by a great number of landowners, cultivators, manufacturers, and merchants. They were found to have conferred the highest benefit on the public, more particularly to those on the line, land having increased in value from 30 to 50 per cent, wherever railroads have been established; in addition to which, it appeared to be a fact, that the proprietors of the Liverpool and the Darlington railroads had already shared from 15 to 20 per cent, upon their extensive outlay and experiments, and that their business has been increasing every week. It cannot admit of doubt that great advantage would accrue to landowners, cultivators, breeders, and dealers in grain, cattle, &c, in the countries through which this railroad would pass, by the facility they would find in transmitting their timber, coals, stone, iron, lime, bricks, grain, hay, straw, flour, cattle, sheep, calves, pigs, butter, butcher's meat, and all other landed produce to the London markets, at the rate of 20 miles an hour, without loss or damage, and at a third of the former expense. This railroad will prove of incalculable advantage to the manufacturers of Norwich, Bury, Peterborough, Ely, Stamford, Nottingham, Newark, Lincoln, Sheffield, Barnsley, Wakefield, Bradford, Leeds, Hull, and Glasgow, and the other northern districts, by enabling them to send their goods by a rapid transit to the metropolis at a small expense, and receive by back carriage the raw materials necessary for their respective trades.
By official returns, it appears that about one half of the home produce of grain, flour, malt, cattle, sheep, calves, pigs, meat, poultry, and butter sent to the London markets, arrives from the counties of Hertford. Essex, Cambridge, Suffolk, Norfolk, Huntingdon, Northampton, Rutland, Lincoln, Nottingham and York; and that the average number of sheep travelling this road weekly exceeds 11,000, with other live stock in proportion; besides which, woollen and other piece goods, Sheffield hardware, and other manufactures, are to be taken into account.
The proposed railway will also considerably benefit the London merchants, brewers, distillers, hop factors, corn factors, mealmen, tea dealers, grocers, drapers, publishers, and all other traders, who return in exchange to these districts, containing a population exceeding three millions and a half of people, articles in their particular lines of equal consumption to the metropolis.
| £ | |
|---|---|
It can be proved also, that the coach traffic alone, between London and York, and the intermediate line of country,amounts to about per annum |
550,500 |
That the carriage by vans and waggons may be taken at half that amount, without including posting and carriage of mails, troops, and military stores |
275,250 |
The inland trade from the ports of Hull, Boston, Holbeach, Spalding, Wisbeach, Lynn, Lowestoffe, Yarmouth, and other northern ports, and shipments of perishable goods, detained by contrary winds, viz, fish, butter, cheese, meats, tallow, hemp, flax, corn, &c, are estimated per annum at |
150,000 |
The carriage of the landed produce and stock to the London markets, as above described, would exceed per annum |
200,000 |
The general merchandise passing to and from the above extensive manufacturing district in the north and the metropolis |
150,000 |
Making together an annual revenue of |
1,325,750 |
The estimated annual expense of conducting the railroad when completed is |
160,000 |
Interest on four millions of capital |
200,000 |
Making together an annual expense of |
360,000 |
The engineer considers the line of country peculiarly favourable for constructing a railroad, both in its levels and the materials that are found on or near the line: he is decidedly of opinion that a railroad can be made at less expense on this than on any other line of country in England of the same distance.
In conclusion, it is submitted that the revenue of the projected railroad, when completed, will far exceed the above estimate. No notice has been taken of the great increase in coach traffic produced by the railway, nor of the intermediate travelling from town to town, and the districts to the north of York, Glasgow, and Edinburgh. Nor should it be forgotten, that long prior to the completion of the outline, the traffic on the first fifty miles could not fail to secure a revenue of 150,000l. per annum, within eighteen months of its commencement.
| £ | £ | |
|---|---|---|
| 2000 acres of land, at per acre 100l. | 200,000 | 460,000 |
| Houses, buildings, and compensation | 260,000 | |
| Bridges, culverts, drains, and masonry | 450,000 | |
| Extra cutting, &c. | 160,000 | |
| Blocks and sleepers, &c. | 160,000 | |
| Ironwork for rails, bolts, pins, &c. | 350,000 | |
| Ballasting and laying, ditto | 160,000 | |
| Excavating, ditching, and fencing, &c. | 400,000 | |
| 12 water stations | 5,000 | 61,800 |
| 12 intermediate pumps | 800 | |
| 50 engines complete | 4,000 | |
| 400 waggons, vans, and trucks | 12,000 | |
| 80 coaches complete | 20,000 | |
| Sheds, benches, and buildings | 20,000 | |
| Branch from Cambridge to Norwich | 800,000 | |
| Contingencies on the above works | 350,000 | |
| Total expense | 3,437,000 | |
Proposed capital 4,000,000l., in 80,000 shares of 50l. each.
Enterprise, capital, and skill have, of late years, been directed with extraordinary energy to the improvement of inland transport, and this important instrument of national wealth and civilisation has received a proportionate impulse. Effects are now witnessed, which, had they been narrated a few years since, could only have been admitted into the pages of fiction, or volumes of romance. Who could have credited the possibility of a ponderous engine of iron, loaded with several hundred passengers and goods, in a train of carriages of corresponding magnitude, and a large quantity of water and coal, taking flight from Manchester, and arriving at Liverpool, a distance of above thirty miles, in little more than an hour? And yet this is a matter of daily and almost hourly occurrence. Neither is the road on which this wondrous performance is effected the most favourable which could be constructed for such machines. It is subject to undulations and incurvations, which reduce the average rate of speed much more than similar inequalities affect the average rate on common roads. The speed of transport thus attained, is not less wonderful than the weights which this power is capable of transporting. Its capabilities in this respect far transcend the exigencies even of the two greatest commercial marts in Great Britain. Loads, varying from fifty to seventy tons, are transported at the average rate of fifteen miles an hour; but the engines would appear to be in this case loaded below their power; and in a recent instance, a load—I should rather say a cargo—of waggons, conveying merchandise to the amount of 230 tons gross, transported from Liverpool to Manchester, at the average rate of twelve miles an hour.
The astonishment with which such performances must be viewed might be somewhat qualified, if the art of transport by steam on railways had been matured, and had attained that full state of perfection, which such an art is always capable of receiving from long experience, aided by great scientific knowledge, and the unbounded application of capital. But such is not the present case. The art of constructing locomotive engines, so far from having attained a state of maturity, has not even emerged from its infancy. So complete was the ignorance of its powers which prevailed even among engineers, previous to the opening of the Liverpool railway, that the transport of heavy goods was regarded as the chief object of the undertaking, and its principal source of revenue. The incredible speed of transport, effected even in the very first experiments in 1830, burst upon the public, and on the scientific world, with all the effect of a new and unlooked-for phenomenon. On the unfortunate occasion which deprived this country of Mr. Huskisson, the wounded body of that statesman was transported a distance of about fifteen miles in twenty-five minutes, being at the rate of thirty-six miles an hour. The revenue of the road arising from passengers since its opening, has, contrary to all that was foreseen, been nearly double that which has been derived from merchandise. So great was the want of experience in the construction of engines, that the company was at first ignorant, whether they should adopt large steam-engines, fixed at different stations on the line, to pull the carriages from station to station, or travelling engines, to drag the loads the entire distance. Having decided on the latter, they have, even to the present moment, laboured under the disadvantage of the want of that knowledge which experience alone can give. The engines have been constantly varied in their weight and proportions, in their magnitude and form, as the experience of each successive month has indicated. As defects became manifest they were remedied; improvements suggested were adopted; and each quarter produced engines of such increased power and efficiency, that their predecessors were abandoned, not because they were worn out, but because they had been outstripped in the rapid march of improvement. Add to this, that only one species of travelling engine has been effectively tried; the capabilities of others remain still to be developed; and even that form of engine which has received the advantage of a course of experiments on so grand a scale to carry it towards perfection, is far short of this point, and still has defects, many of which it is obvious time and experience will remove. If, then, travelling steam-engines, with all the imperfections of an incipient invention—with the want of experience, the great parent of practical improvements—with the want of the common advantage of the full application of the skill and capital of the country—subjected to but one great experiment, and that experiment limited to one form of engine, and conducted, as I shall presently show, not on the wisest principles, nor with the most liberal policy; if, under such disadvantages, the effects to which I have referred have been produced, what may we not expect from this extraordinary power, when the enterprise of the country is unfettered,—when greater fields of experiments are opened,—when time, ingenuity, and capital, have removed the existing imperfections, and have brought to light new and more powerful principles? This is not mere speculation on possibilities, but refers to what is in a state of actual progression. Railways are in progress between the points of great intercourse in the United Kingdoms, and travelling steam-engines are in preparation in every quarter for the common turnpike roads; the practicability and utility of that application of the steam-engine, having not only been established by experiment to the satisfaction of their projectors, but proved before the legislature so conclusively, as to be taken for the foundation of Parliamentary enactments, and upon which large capital may be safely invested.
The important commercial and political effects attending such increased facility and speed in the transport of persons and goods, which were proved before Parliament in the sessions of 1831, 1832, and 1833, are too obvious to require any very extended notice here. A part of the price (and in many cases a considerable part) of every article of necessity or luxury, consists of the cost of transporting it from the producer to the consumer; and, consequently, every abatement or saving in this cost, must produce a corresponding reduction in the price of every article transported; that is to say, of every thing which is necessary for the subsistence of the poor, or for the enjoyment of the rich, of every comfort, and of every luxury of life. The benefit of this will extend, not to the consumer only, but to the producer: by lowering the expense of transport of the produce, whether of the soil or of the loom, a less quantity of that produce will be spent in bringing the remainder to market, and, consequently, a greater surplus will reward the labour of the producer. The benefit of this will be felt even more by the agriculturist than by the manufacturer; because the proportional cost of transport of the produce of the soil is greater than that of manufactures. If 200 quarters of corn be necessary to raise 400, and 100 more be required to bring the 400 to market, then the net surplus will be 100. But if by the use of steam-carriages the same quantity can be brought to market with an expenditure of 50 quarters, then the net surplus will be increased from 100 to 150 quarters profit; and either the profit of the farmer, or the rent of the landlord, must be increased by the same amount; the same applies to cattle, &c.
But the agriculturist would not merely be benefited by an increased return from the soil already under cultivation. Any reduction in the cost of transporting the produce to market would call into cultivation tracts of inferior fertility, and uncultivated land, the returns from which would not at present repay the cost of cultivation and transport of manure. Thus land would become productive which is now waste, and an effect would be produced equivalent to adding so much fertile soil to the present extent of the country. It is well known that land of a given degree of fertility will yield increased produce by the increased application of capital manure and labour. By a reduction in the cost of transport, a saving will be made which may enable the agriculturist to apply to tracts already under cultivation the capital thus saved, and thereby increase their actual production. Not only, therefore, would such an effect be attended with an increased extent of cultivated land, but also with an increased degree of cultivation in that which is already productive; and manual labour would be extended, and the poor and county rates reduced.
It has been said that in Great Britain there are above a million of horses engaged in various ways in the transport of passengers and goods, and that to support each horse requires as much land as would upon an average support eight men. If this quantity of animal power were displaced by steam-engines, and the means of transport drawn from the bowels of the earth, instead of being raised upon its surface, then, supposing the above calculation correct, as much land would become available for the support of human beings as would suffice for an additional population of eight millions; or, what amounts to the same, would increase the means of support of the present population by about one third of the present available means. The land which now supports horses for transport on turnpike roads would then support men, or produce corn for food, and the horses return to agricultural pursuits.
The objection that a quantity of land exists in the country capable of supporting horses alone, and that such land would be thrown out of cultivation, scarcely deserves notice here. The existence of any considerable quantity of such land is extremely doubtful. What is the soil which will feed a horse, and not feed oxen, cows, or sheep, or produce food for man? But even if it be admitted that there exists in the country a small portion of such land, that portion cannot exceed, nor indeed equal, what would be sufficient for the number of horses which must after all continue to be employed for the purposes of husbandry, pleasure, and a variety of cases where steam must necessarily be inapplicable. It is to be remembered, also, that the displacing of horses in one extensive occupation, by diminishing their price, must necessarily increase the demand for them in others.
The reduction in the cost of transport of manufactured articles, by lowering their price in the market, will stimulate their consumption. This observation applies, of course, not only to the consumer at home, but to foreign markets. In the latter, we already, in many branches of manufacture, command a monopoly. The reduced price which we shall attain by cheapness and facility of transport will still further extend and increase our advantages. The necessary consequence will be an increased demand for manufacturing population; and this increased population again reacting on the agricultural interests, will form an increased market for that species of agricultural produce. So interwoven and complicated are the fibres which form the texture of the highly civilised and artificial community in which we live, that an effect produced on any one point, is instantly transmitted to the most remote and apparently unconnected parts of the system.
The two advantages of increased cheapness and speed, besides extending the amount of existing traffic, call into existence new objects of commercial intercourse. For the same reason that the reduced cost of transport, as I have shown, calls new soils into cultivation, it also calls into existence new markets for manufactured and agricultural produce. The great speed of transit, which has been proved to be practicable, must open a commerce between distant points in various articles, the nature of which does not permit them to be preserved so as to be fit for use beyond a certain time. Such are, for example, many species of vegetable and animal food, which, at present, are confined to markets at a very limited distance from the grower or feeder. The truth of this observation is manifested by the effects which have followed the intercourse by steam on the Irish Channel. The western towns of England have become markets for a prodigious quantity of Irish produce, which it had been previously impossible to export. If animal food be transported alive from the grower to the consumer, the distance of the market is limited by the power of the animal to travel, and the cost of its support on the road. It is only particular species of cattle which bear to be carried to market on common roads and by horse carriages. But the peculiar nature of a railway, the magnitude and weight of the loads which may be transported on it, and the prodigious speed which may be attained, render the transport of cattle, meat or fish of every species, to almost any distance, both easy and cheap. In process of time, when the railway system becomes extended, the metropolis and populous towns will therefore become markets, not, as at present, to districts within limited distances of them, but to the whole country within 200 miles of the metropolis.
The moral and political consequences of so great a change in the powers of transition of persons and intelligence from place to place, are not easily calculated. The concentration of mind and exertion which a great metropolis always exhibits, will be extended in a considerable degree to the whole realm. The same effect will be produced as if all distances were lessened in the proportion in which the speed and cheapness of transit are increased. Towns, at present removed some stages from the metropolis, will become its suburbs; others, now at a day's journey, will be removed to its immediate vicinity; business will be carried on with as much ease between them and the metropolis, as it is now between distant points of the metropolis itself. The ordinary habitations of various classes of citizens engaged in active business in the towns, will be at what now are regarded considerable distances from the places of their occupation. The salubrity of cities will thus be increased, by superseding the necessity of heaping the inhabitants together, story upon story, within a confined space; and by enabling the town population to spread itself over a larger extent of surface, without incurring the inconvenience of distance. Let those who discard speculations like these as wild and improbable, recur to the state of public opinion, at no very remote period, on the subject of steam navigation. Within the memory of persons who have not yet passed the meridian of life, the possibility of traversing by the steam-engine the channels and seas that surround and intersect these islands, was regarded as the dream of enthusiasts. Nautical men and men of science rejected such speculations with equal incredulity, and with little less than scorn for the understanding of those who could for a moment entertain them. Yet we have witnessed steam-engines traversing, not these channels and seas alone, but sweeping the face of the waters round every coast in Europe, and even ploughing the great oceans of the world. If steam be not used as the only means of connecting the most distant habitable points of our planct, it is not because it is inadequate to the accomplishment of that end, but because local and accidental causes limit the supply of that material from which at the present moment it derives its powers. But that power is at this moment being accomplished: a steam packet of 1000 tons burthen is now building at New York, to be propelled by an engine of 260 horse power, with double paddles, designed as a passage vessel between New York and Liverpool, and to carry 1000 passengers every trip, a distance of about 3500 miles across the Atlantic, in twelve days, without regard to wind, weather, or tides, at the rate of fifteen miles an hour, this may be considered a floating island.
I propose, in the present article, to lay before you some account of the means whereby the effects above referred to have been produced; of the manner and degree in which the public have availed themselves of these means; and of the improvements of which they seem to me to be susceptible.
In considering the means of inland transport, there are two distinct points to which I should solicit attention, viz, the road, and the power of traction or impulsion. A road is a contrivance by which the resistance opposed to a body moving on the surface of the earth, arising from the inequalities of that surface, may be diminished; and as it diminishes that resistance, in the same proportion does it accomplish its object. The power of traction or impulsion is efficient in proportion to its intensity, and the rate at which it is capable of exerting that intensity in reference to time. On the intensity of the power depends the resistance it can overcome, and this intensity is therefore proportional to the load. On the rate at which this power can be produced and exerted, depends the speed which is attainable by it.
The roads most commonly used are those of water, or canals; those of stone, or turnpike roads; and those of iron, or railroads. In all these species of roads, the first and most necessary quality is, that the line should be as nearly as possible level. As this, however, cannot be perfectly attained, there are contrivances peculiar to each kind of road, by which the difficulty attending the want of perfect level may be overcome. But as such contrivances constitute the greatest expense, whether in the original construction of the road, or in working upon it after it has been constructed, that course should always be selected for the line which offers the fewest possible inequalities, and those the smallest in amount.
Canals possess advantages over all other roads, in being able to support an almost unlimited amount of load. The pressure on the wheels of carriages on a railroad is limited by the strength of the rail, and is seldom more than about three tons upon each wheel. The pressure on the wheels of carriages on a turnpike road is limited by the strength of the crust of the road. On the broad wheels of the heaviest waggons the pressure never exceeds two tons; but the weight capable of being sustained by a canal is only limited by the magnitude of the boats which the breadth of the canal allows to float upon it. In fact, the weight of the boat and its cargo is equal to the weight of the water which is displaced by the part of the boat immersed in the canal.
In considering the power of traction or impulsion necessary to move a body, whether on a canal or on a road. I must carefully distinguish that force which is requisite to put the body from a state of rest into a state of motion, from that which is requisite to sustain the motion when once imparted to it. If a body were sustained by a surface perfectly level and perfectly smooth, so as to oppose no resistance whatever to motion upon it, without friction, the body once put in motion by an impulse would continue to move for a considerable time, without the application of any further impulsion or traction. But such a surface as is here supposed has no practical existence: although, as already explained, it is the object of roads of every kind to approach as near to this imaginary limit as possible.
The continual power of traction necessary to sustain the motion of a body, therefore, arises from the resistance produced by the action of the body on the road; and it is only by investigating the nature of this resistance, and its law, that the necessary qualities in the drawing or impelling power can be fully understood. As the presence of resistance on the road does not supersede the necessity of the first impulse, it follows that every mass which is to be moved, requires a much greater exertion of power at starting than subsequently; but, as this exertion is continued only for a short period. I may omit its consideration, when that purpose is to investigate the power necessary to keep it in constant action.
The power of traction necessary to sustain the progressive motion of a boat floating on a liquid arises from the resistance of the liquid lying immediately before the boat. It is necessary that the vessel should divide the fluid which lies in its way; and the force necessary to move this with the speed of the vessel must be supplied by the power of traction or impulsion, whatever that power may be. It will be sufficiently obvious, on consideration, that the quantity of liquid which is thus driven or divided before the vessel, depends, not on the whole magnitude of the vessel, but on the magnitude of the transverse section of that part of the vessel which is beneath the surface of the liquid. It is true that this conclusion requires some modification in practice, and that the shape of the vessel and other circumstances should be taken into account, in accurate calculations; but the resistance mainly depends, as above stated, on the transverse section, and may be considered, cæteris paribus, proportional to that section. Now, the more rapidly the vessel is moved, the more rapidly the liquid must be removed before it, and, therefore, the greater the force necessary to impel it in this manner; and hence a double speed requires that the liquid should be impelled with almost a double force. But besides this, it is to be considered, that when the vessel acquires a double speed, it moves in the same time through a double space, and therefore must impel a double quantity of the liquid. Since, therefore, it impels a double quantity, and every portion of that with almost a double force, the resistance which it has to overcome must be increased in a threefold proportion. Hence we see, that to give a vessel moving in a liquid a double velocity, requires that the power of traction or impulsion should be increased in a threefold proportion. In the same manner, it will be easily made out, even by the general reader, that a threefold velocity will require about sixfold power of traction or impulsion, and so on; the resistance and the necessary power of traction increasing not merely in the proportion of the speed, but in the proportion of what arithmeticians call the square of the speed.
Even this statement must be received in a qualified form, and limited in its application to moderate rates of motion; because it is demonstrable, that there is a practical limit of speed, beyond which a vessel cannot be impelled through a fluid, and that limit is by no means a wide one. Notwithstanding the application of the immense power of steam to vessels plying between points of great intercourse. I believe that a greater speed than from ten to twelve miles an hour has never yet been attained independently of the effect of currents.
To the power of impelling a vessel through water we see, therefore, that there is a narrow limit; but if this limit be narrow as applied to vessels in the open sea, it is still more so when applied to vessels in confined channels, such as canals. In this case the theoretical reasoning above given would require great modification; and the resistance, which in practice is in every case greater than in the proportion of the square of the velocity, is considerably above that proportion in the case of canals. Experiments have been made by Mr. Bevan on the resistance to vessels moved at different speeds in water, and we find by them that a vessel moved on the Paddington Grand Junction Canal, at the rate of 2 miles an hour, loaded with 21 tons, required force of traction amounting to 77 lbs.; while the same vessel moved at the rate of something less than 4 miles an hour, required a force of traction amounting to 308 lbs. Thus, while the speed was increased in a somewhat less proportion than 2 to 4, the resistance was increased in the proportion of 2½ to 10. Experiments made by Mr. Walker on the London Docks give the resistance also in a greater proportion than that of the square of the velocity. Many other facts confirm this conclusion; but a singular anomaly appears to have been presented by some experiments made on the Forth and Clyde Canal in July, 1830. A twin-boat, loaded with 5 tons, 16 cwt. 41 lbs., and dragged by horses, was furnished with an instrument by which the force of traction was measured, and it was found, that at and under eight miles an hour, the resistance was in conformity with the principle just explained, but that when higher rates of speed were attained, although the resistance increased, it did not increase in nearly so rapid a proportion. This arose from the circumstance of the boat-speed having been more raised or less draft in the water by the effect of traction on the bank at the high speed. But be this as it may, the deviation from the law takes place in such extreme cases, and 30 INLAND TRANSIT, under such peculiar circumstances, that no general conclusion can be safely drawn from it. I can venture to affirm, that a similar result would not be found to attend the propulsion of a boat by a steamengine acting on paddle-wheels.
From what has been stated, it appears that the resistance to the motion of a vessel in a liquid does not increase in proportion with the weight of the vessel and its cargo. Two vessels of equal transverse section, but different lengths, may have very different weights, and yet suffer nearly equal resistance from the liquid in which they are moved. This forms a very important circumstance favourable to transport by canals, as compared with transport on other roads. On roads, the resistance is always in proportion to the weight; and by combining this circumstance with what has been already explained respecting the dependence of the resistance on the velocity, it will be easily perceived, that the most advantageous mode in which canals can be used is in the transport of very great weights at a very low speed. Indeed, independently of the limit of speed imposed by the law of resistance, there are other circumstances connected with canals which render any considerable rate of motion inapplicable to them; and one of the principal of these is, the wear and even destruction of the embankments, which would be produced by the rapid flow of water caused by boats propelled through them at any rapid rate of motion; although I am of opinion that a light steam boat can be propelled with more speed on a canal than on the sea, with equal force. But when a carriage is drawn or impelled along a hard and level road, the motion which it receives from the first impulse would continue undiminished for a short time, if the road and the faces of the wheels were perfectly smooth, and no resistance of the air. This is a consequence of one of the first and most simple properties of matter,—inertia; that property in virtue of which a body would remain for ever at rest, if not put into a state of motion by the action of some external force. But the formation of a perfectly smooth road, and of perfectly smooth wheels to move on that road, is impracticable in this country. The surface of the road and the surface of the wheels, whatever is their materials, or with whatever care they may be constructed, will be covered with asperities; which will obstruct the motion of the carriage in proportion to their number and magnitude, and in proportion to the weight with which the carriage presses upon them. The more these asperities are removed, therefore, the less will be the force of traction necessary to continue the motion of a carriage loaded with a given weight. Experiments made on an extensive scale by Coulomb, Ximenes, and other philosophers, have established satisfactorily, that, when the quality of the road and of the wheels are the same, the resistance of the motion of the carriage, arising from the roughness of the road, will always be in proportion to the weight of the carriage. A double weight will offer double resistance, a triple weight a triple resistance, and so on. The same experiments establish another consequence, materially affecting all questions respecting the work performed on roads. This result is, that the resistance to the motion of a carriage is altogether independent of the velocity of that motion; and that, whatever be the speed at which the carriage moves, the resistance will suffer no change. Indeed, any slight change which may have been indicated, rather shows a diminution of resistance with increased speed; but for practical purposes the resistance may be regarded as constant, and quite independent of the velocity. I therefore infer, that the power of traction necessary on level roads, whether they be roads of stone or roads of iron, will always be in proportion to the load, and independent of the speed.
This becomes one of the most striking features of difference between the effects in favour of roads and against canals. In the latter, every increase of speed renders a proportionate increased power of traction necessary; while in the former no increased power of traction whatever is needed. If a carriage be propelled on a road ten miles in five hours, or ten miles in one hour, the power of traction must be precisely the same in both cases; but if a boat be propelled on a canal ten miles in one hour, the power of traction must be more than ten times that which would be necessary to carry it ten miles in five hours. This observation will be equally applicable to turnpike roads and railroads, as compared with canals; and it will lead to the inference that there is a limiting speed, at which the effect of canals must equal the effect of a hard level road travelled by a carriage; and that below this limit the canal has the advantage, while, above it, the advantage lies with the road. As the resistance to the boat in the water has an immediate dependence on its rate of motion, it follows, that by reducing that rate of motion without limit, the resistance may be also reduced in a proportionate limit; while, on the other hand, the resistance to a carriage moving on a railroad, being independent of the speed, the reduction of speed can cause no diminution in the resistance. It is therefore possible to assign such a velocity to a boat moved on a canal, that the resistance will exactly equal the resistance of the road to the carriage loaded with a weight equal to that of the boat.
Now, as the resistance of a canal below this limit will be less, while the resistance of the road will remain the same, it follows that at lower velocities the canal, cæteris paribus, will present less resistance to the force of traction. On the other hand, by increasing the speed beyond the limit assigned, the resistance of the canal increases faster than the square of the velocity, while the resistance of the road suffers no increase whatever. Hence, above this limit, the road will possess considerable advantage over a canal.
But besides this, the resistance of the road to the carriage increases in the direct proportion of the weight of the load; while the resistance of a canal to the boat is, comparatively speaking, but slightly increased by an increase of the weight. From these circumstances it is easy to infer, that very great weights, moved at very low velocities, require a less power of traction on canals than on common roads. But, on the other hand, when the speed is increased, or when the load is more moderate in its amount, the advantage of a common road prevails, and more especially with reference to the increase of speed. The greatest speed at which canals can be advantageously worked is from two to two and a half miles an hour. Now, we shall see hereafter, that when adequate moving powers are applied, even with very considerable weights, the speed attainable, without loss of advantage on roads, bears a large proportion to this. Railroads are contrivances for obtaining a surface for the wheels of carriages to roll upon, smoother than the surface of a turnpike road, whether Macadamised or paved. To accomplish this, bars of iron are constructed of a suitable length, and laid upon the road, so that they present upwards a smooth surface; their extremities resting upon large blocks of stone firmly imbedded in the earth, called sleepers. These iron bars, which are called rails, are firmly connected end to end, and extend from sleeper to sleeper along the whole line of road, so as to form one continuous smooth track or line of iron surface, upon which the wheels of the carriage roll. Two parallel tracks of these bars are placed at a distance, corresponding to that of the width of the wheels of the carriage intended to run upon them. The wheels are constructed with a ledge of iron projecting at right angles to the faces of their tires, which as they roll catches the inner surface of the rail, so as to prevent the carriage from slipping off at either side. There are several forms of rails in use, some have a saddle edge to receive the vec of the wheel.
When the surfaces of the tire and the rail are clean, the resistance which they present is extremely small, owing to the hardness of the material of which they are composed, and the smoothness of which its surface is susceptible. Two parallel tracks of rails upon which the wheels of the same carriage roll are called "a single line of railway." In order to enable carriages on such a line moving in contrary directions to pass one another, retiring places called sideings are provided at certain intervals, into which a carriage may be turned, so that one may wait till another passes. This provision is indispensable where the points of intercourse are connected only by a single line; but, in cases of great intercourse, two lines are sometimes provided for carriages moving in opposite directions, in which the delay produced by carriages meeting in opposite directions is avoided.
The power of traction required on a well-constructed level railway is generally estimated at the 240th part of the load drawn. The smallness of this proportion gives rise to a consequence of great practical importance when inclined planes occur; as must always be the case at points where the level of the country road changes. In addition to the ordinary resistance of the rails, the power of traction in ascending must overcome the tendency of the load to descend by its gravity. This tendency, as is well known, bears a proportion to the load equivalent to the elevation of the plane. If the plane rise 1 foot in 100, the tendency of a load of 100 tons to descend will be 1&1nbsp;ton. Upon this principle, if the plane rise 1 foot in 240, the power of traction, compared with that which is necessary upon a level, will be double. An ascent of 2 feet in 240, or 1 in 120, will require a three-fold power of traction; an ascent of 3 feet in 240, or 1 in 80, will require a four-fold power of traction, and so on. Hence it is obvious how enormously the drawing power must be increased even by the slightest incurvation. An ascent of 1 in 240, or 17 feet in 1400 yards, which requires the power of traction to double its energy, is scarcely perceptible to the eye; and the rise of 1 in 96 at Rainhill, on the Manchester line, which is barely perceivable, requires the power of traction to increase its intensity in nearly a four-fold proportion. It follows, therefore, that whatever agent may be employed as a propelling power on a railroad having incurvations upon it, however inconsiderable, must be susceptible of varying its energy and speed within very wide limits. This constitutes one of the greatest practical difficulties which the railroad system has to encounter.
Upon common turnpike roads or paved streets, this inconvenience is less than on railroads. The power of traction necessary on these roads is very variable, owing to the want of uniformity in their surfaces; but on a level Macadamised road it is estimated, on an average, by Mr. Gurney, as a 12th part of the weight of the load. Thus a carriage, weighing 12 cwt., would require a power of traction of 1 cwt.; a carriage weighing 6 tons requires a power of traction amounting to half a ton, and so on. The increased power of traction required by an ascent on a turnpike road is estimated exactly in the same manner as for railroads. An ascent of 1 foot in 12 will add to the power of traction necessary on a level an increased power amounting to one-twelfth of the load, and thus such an ascent would require the power of traction to be doubled; but all ascents less abrupt than 1 in 12 would not require the power of traction to be increased in so great a degree as double its amount on the level. It therefore follows, that so great a susceptibility of increase is not necessary in the powers of traction used on common roads in cases of ascent, as in those used on railroads. This arises not from any advantage possessed by common roads compared with railroads, but from the very reverse. The increase to the power of traction required by an ascent on a common road, is exactly the same in amount as that which would be required by an ascent of the same elevation on a railroad. But the power of traction necessary on a level common road is so great, that the increase caused by an elevation becomes no considerable addition; while the power of traction on a level railroad is so small, that the increase produced by the smallest inclination is severely felt.
That a railroad should be effective, it is therefore necessary that a propelling power should be used capable of great variation in its intensity, or that additional powers of traction should be provided at every inclination, or, finally, that, in the original construction of the road, a level be maintained as near as possible, and in no case should the inclination exceed 14 feet in a mile. Valleys must, therefore, be traversed by embankments or aqueducts, and hills intersected by artificial chasms of open cutting. To penetrate them by tunnels, except in very rare cases and short distances, is inexpedient; for the travelling steam-engine generally used on railroads cannot be used in a tunnel, owing to the air being rendered unfit for breathing by the effect of the fire. Besides the resistance that the air in the tunnel will give to the carriage passing through it, even were tunnels practicable, the great original expense of construction forms a strong objection.
A turnpike road, on the other hand, is usually carried in a winding course, through an undulating country, avoiding hills of great acclivity; and though the length will be thereby increased, yet the total expenditure of the power of traction will be diminished.[2] The power of traction necessary on common roads in different states of repair, or differently constructed, is subject to great variation. Experiments on this power were made by the direction of the commissioners for the Holyhead Road, with a view to ascertain the best mode of constructing and repairing that road. The result of these experiments shows that the power of traction over a level well-constructed pavement, varies from 32 to 39 lbs. for every ton. A waggon, weighing 21 cwt. 8 lbs., drawn over a well-laid pavement in Piccadilly, required a power of traction, varying from 33 to 40 lbs. In a place where the pavement was uneven, and worked into holes, the power was increased to 48 lbs.; but it may be assumed, that the power of traction on the best laid pavement—such as that which may be seen before the new buildings in the Strand, and in Parliament Street, when newly paved is at the rate of about 32 lbs, to the ton. On a broken stone surface of old flint road, the traction is about 64 lbs., being double that of a pavement. On a gravel road, the power of traction is nearly 150 lbs, to the ton; on a broken stone road, having a rough pavement foundation, the traction is 45 lbs, to the ton.
From these results, it appears that Mr. Gurney's estimate of the comparative traction on railroads and common roads is not supported by experiment. The traction on a railroad being about 9 lbs, in the ton, and that on the best laid pavement being 32, the latter is three and a half times the former. The traction on a well-made stone surface of old flint road is about seven times the traction on a railway. On a gravel road, it is about fifteen times, and on a broken stone road, with a rough pavement foundation, it is about five times the traction of the railway. I may not be, perhaps, far from the truth in assuming that the average traction of level turnpike roads, in the summer or frosty season, is about twelve times that of railroads; and consequently that the same power acting on a railroad, will always draw or impel twelve times the load which it can transport on a common road. But I am decidedly of opinion that a steam coach or carriage cannot be used on turnpike roads in the winter season, more particularly after a sharp frost, on a new road; and the repairs of the old road will cause that resistance at all times, that will render the attempt useless.
Having noticed the different kinds of roads over which inland transit is effected. I shall now consider the powers of traction, or the motive forces which are used on these roads. These are at present either that of horses or steam-engines.
The law which regulates the expenditure of animal strength in labour, has never yet been accurately ascertained by observation; nevertheless, there are certain general facts known respecting it, which, though not capable of being reduced to a mathematical expression, are yet sufficiently defined to lead to useful conclusions. In all cases where a horse is used as the means of transit, he must, besides the load which he bears, move the weight of his own body, and a great portion of his strength is thus employed. This portion is found to increase at a rapid rate with the velocity, so that as the speed of his motion increases, the quantity of power which he can spare to his load is as rapidly diminished. In fact, between the load which he bears, and the speed with which he is capable of moving it, there is a certain relation, which, if it could be ascertained exactly, and expressed mathematically, would give the whole theory of animal power considered as a mechanical agent. There are two obvious limiting states, between which, at some intermediate point, the effect of the horse's power is a maximum. There is a certain load which the ani, mal is barely able to support, but unable to move with any useful speed. On the other hand, there is a certain speed, at which the animal is barely able to move his own body, but unable to support any useful load. In both these cases, his useful effect as an agent of labour, vanishes; and between these limits, it varies according to different proportions. An empyrical formula, assigned by Euler, and quoted by numerous mechanical writers, comes perhaps sufficiently near the practical effects for our purposes.[3] Let us suppose that the greatest speed of which a horse is capable when unloaded, is fifteen miles an hour, and the greatest load which he is capable of bearing without moving with any useful speed, to be divided into 225 equal parts;—then the load which he is capable of bearing at fourteen miles an hour, will be one of these equal parts; that which he is capable of bearing at thirteen miles an hour will be four of these parts; at twelve miles an hour, nine of them, and so on; the load being expressed by the squares of the successive integer numbers increasing as the speed with which he moves is decreased. By multiplying the load by the speed, the useful effect is obtained; and by this mode of calculation, it would follow that the greatest effect of horse power is obtained when the animal moves at one third of that rate which is the greatest of which he is capable when unloaded; and that the load which he bears at that speed will be four-ninths of the greatest load which he is capable of bearing with any useful motion for two hours. From this we may infer generally, that in the use of animal power, as a mechanical mover, advantage is lost with every increase of speed beyond a very moderate limit; and that at certain rates, and those not high in degree, all useful effects disappear.
It is found in practice, that a waggon used on a turnpike road, and loaded to the amount of eight tons, may be drawn by horses, at the rate of two miles and a half an hour,—the horses working for eight hours daily. Thus the performance of a horse in this way will amount to one ton transported twenty miles a-day. A mail-coach, weighing two tons, and travelling at the rate of ten miles an hour, may be worked on a line of road in both directions by a number of horses equal to the number of miles. Thus, the performance of each horse would amount to two tons carried two miles daily, or four tons carried one mile. In the case, however, of horses working in this way, it appears, by a petition of coach proprietors presented to the House of Commons, that it is necessary to renew the stock every third year; from whence we must infer that the animal is overworked.
From what has been explained, respecting the resistance of fluids, and from the relation which I have shown to subsist between the speed of horses and the performances which they are able to effect, it will be apparent that that rate of motion which renders the resistance of a fluid least injurious to the effect produced, is also that speed at which a horse can work with the greatest possible effect. This speed is from two and a half to three miles an hour; and I accordingly find, that when horse power is used to propel a boat on a canal, the effect is a maximum at that rate of motion; but if a higher rate be attempted. I find, as might be easily anticipated from the principles already laid down, that the diminution of effect takes place in an immensely rapid proportion. Even if the resistance of a fluid were not increased, the effect of a horse's power, by the condition of his nature, would be materially reduced by every increase of speed; and, on the other hand, even were a horse capable of working with the same effect at an increased speed, the resistance of a fluid, increasing in a greater proportion than the square of the speed, would impair the total effect. But, in fact, these two causes cooperate; and both theory and experience agree in the result, that horse power at greater speed than about three miles an hour, is altogether incompatible with any useful effect upon canals; and ten miles an hour on turnpike roads, for any useful purpose.
To render intelligible the advantages which attend the use of steam as a moving power in the transit of loads over land, whether by canals or roads, it will be necessary to premise a few observations respecting the steam-engine. It is a universal property of matter, that by the application of heat, so as to raise its temperature, it suffers an increase in its magnitude. Also in different substances, when certain temperatures are attained by the application of fire or other methods of heating, they undergo a change of form. Solids, at certain temperatures, are converted into liquids; and liquids, in like manner, when heated to certain degrees, become aeriform fluids or gases. These changes are familiar to every one in the ordinary phenomena attending water. Below the temperature of 32° of the common thermometer, that substance exists in the solid form, and is called ice. Above that temperature, it passes into the liquid state, and is called water; and when raised to the temperature of 212°, under ordinary circumstances, it passes into the aeriform state, and is called steam. It is to this last change that I wish at present principally to call the attention of the reader. In the transition of water from the liquid state to the state of vapour or steam, an immense change of bulk takes place. In this change, a solid inch of water enlarges its size about 1700 times, and forms 1700 solid inches of steam. This expansion takes place accompanied with a certain force of pressure, by which the vapour has a tendency to burst the bounds of any vessel which contains it. The steam which fills 1700 solid inches, at the temperature of 212°, will, if cooled below that temperature, return to the liquid form, and occupy only one solid inch, leaving 1699 solid inches vacant; and, if it be included in a close vessel, leaving the surfaces of that vessel free from the internal pressure to which they were subject before the return of the water to the liquid form. If it be possible, therefore, alternately to convert water into vapour by heat, and to reconvert the vapour into water by cold. I shall be enabled alternately to submit any surface to a pressure equal to the elastic force of the steam, and to relieve it from that pressure, so as to permit it to move in obedience to any other force which may act upon it. Or again, suppose that we are enabled to expose one side of a movable body to the action of water converted into steam, at the moment that we relieve the other side from the like pressure by reconverting the steam which acts upon it into water, the movable body will be impelled by the unresisted pressure of the steam on one side. When it has moved a certain distance in obedience to this force. I suppose that the effects are reversed. Let the steam which pressed it forwards be now reconverted into water, so as to have its action suspended; and at the same moment, let steam raised from water by heat be caused to act on the other side of the movable body; the consequence will obviously be, that it will now change the direction of its motion, and return in obedience to the pressure excited on the opposite side. Such is, in fact, the operation of an ordinary low pressure steam-engine. The piston or plug which plays in the cylinder is the mover to which we have referred. The vapour of water is introduced upon one side of that piston at the moment that a similar vapour is converted into water on the other side, and the piston moves by the unresisted action of the steam. When it has arrived at the extremity of the cylinder, the steam which just urged it forward is reconverted into water, the piston is relieved from its action, and returns again to the bottom of the cylinder, by which a partial motion is continued. At the same moment, a fresh supply of steam is introduced upon the other side of the piston, and its pressure causes the piston to be moved in a direction contrary to its former motion. Thus, the piston is moved in the cylinder alternately in the one direction and in the other, with a force equivalent to the pressure of the steam which acts upon it. A strong metal rod proceeds from this piston, and communicates with proper machinery, by which the alternate motion of the piston backwards and forwards, or upwards and downwards in the cylinder, may be communicated to whatever body is intended to be moved.
The power of such a machine will obviously depend on the dimensions of the boiler, and on the magnitude of the piston or the movable surface which is exposed to the action of the steam, and partly on the pressure or temperature of the steam itself. The object of converting the steam into water by cold, upon that side of the piston towards which the motion takes place, is to relieve the piston from all resistance to the moving power. This renders it unnecessary to use steam of a very high pressure, inasmuch as it will have no resistance to overcome, except the friction of the piston with the cylinder, and the ordinary resistance of the load which it may have to move. Engines constructed upon this principle, not requiring, therefore, steam of a great pressure, have been generally called 'low-pressure engines.' The re-conversion of the steam into water requires a constant and abundant supply of cold water, and a fit apparatus for carrying away the water which becomes heated, in cooling the steam, and for supplying its place by a fresh quantity of cold water. It is obvious, that such an apparatus is incompatible with great simplicity and lightness, nor can it be applied to cases where the engine is worked under circumstances in which a fresh supply of water cannot be had.
The re-conversion of steam into water, or, as it is technically called, the condensation of steam, is, however, by no means necessary to the effective operation of a steam-engine. From what has been above said, it will be understood that this effect relieves the piston of a part of the resistance which is opposed to its motion. If that part of the resistance were not removed, the pressure of steam acting upon the other side would be affected in no other way than by having a greater load or resistance to overcome; and, if at pressure were proportionately increased, the effective power of the machine would remain the same. It follows, therefore, that if the steam upon that side of the piston towards which the motion is made were not condensed or expelled, the steam urging the piston forwards on the other side would require to have a degree of intensity greater than the steam in a low-pressure engine, by the amount of the pressure of the uncondensed steam on the other side of the piston.
An engine working on this principle has, therefore, been called a high pressure engine. Such an engine is relieved from the incumbrance of all the condensing apparatus and of the large supply of cold water necessary for the reduction of steam to the liquid form; for, instead of being so reduced, the steam is, in this case, simply allowed to escape into the atmosphere. The operation, therefore, of high-pressure engines will be readily understood. The boiler producing steam of a very powerful pressure, is placed in communication with a cylinder furnished in the usual manner with a piston; the steam is allowed to act upon one side of the piston, so as to impel it from the one end of the cylinder to the other. When it has arrived there, the communication with the boiler is reversed, and the steam is introduced on the other side of the piston, while the steam which has just urged the piston forwards is permitted to escape into the atmosphere. It is evident, that the only resistance to the motion of the piston here, is the pressure of that portion of steam which does not escape into the air; which pressure will be equal to that of the air itself, inasmuch as the steam will continue to escape from the cylinder as long as its elastic force exceeds that of the atmosphere. In this manner the alternate motion of the piston in the cylinder will be continued; the efficient force which urges it being estimated by the excess of the actual pressure of the steam from the boiler above the atmospheric pressure. The superior simplicity and lightness of the high-pressure engine must now be apparent, and these qualities recommend it strongly for all purposes in which the engine itself must be moved from place to place; for this improvement we are indebted to Mr. Perkins's talented genius.
The steam-engine, therefore, consists of two distinct parts,—the boiler, which is at once the generator and magazine of steam, and the cylinder with its piston, which is the instrument by which this power is brought into operation and rendered effective. The amount of the load or resistance which such a machine is capable of moving, depends upon the intensity or pressure of the steam produced by the boiler, and on the magnitude of the surface of the piston in the cylinder, and the machinery upon which that steam acts. The rate or velocity of the motion depends, not on the power or pressure of the steam, but on the rate at which the boiler is capable of generating it. Every stroke of the piston consumes a cylinder full of steam; and, of course, the rate of the motion depends upon the number of cylinders of steam which the boiler is capable of generating in a given time. These are two points which it is essential should be distinctly understood, in order to comprehend the relative merits of the boilers used in travel, ling steam-engines, or steam carriages.
The motion which is primarily produced in a steam-engine, is a reciprocating or alternate motion of the piston from end to end of the cylinder; but the motion which is necessary to be produced for the purposes to which the engine is applied, is rarely or never of this nature. This primary motion, therefore, is almost always modified by some machinery interposed between the piston and the object to be moved. The motion most generally required is one of rotation, and this is accomplished by connecting the extremity of the piston-rod with a contrivance constructed on the revolving axle, called a crank. This contrivance does not differ in principle from the common winch, or from the key which winds a clock. The motion of the piston-rod backwards and forwards turns such a winch. At each termination of the stroke, the piston, from the peculiar position of the crank, loses all power over it. To remedy this, two cylinders and pistons are generally used, which act upon two cranks placed on the axle at right angles to each other; so that at the moment when one of the pistons is at the extremity of its stroke, and loses its power upon one crank, the other piston is at the middle of its stroke, and in full operation on the other crank. By these means an unintermitting force is kept in action.
So far as relates to the capability or power of the steam-engine, no difficulty attends its application to inland navigation. Either low pressure or high pressure engines may be applied to this purpose. Lightness and space are of some importance, but not so indispensable as to exclude low-pressure engines from the barges on canals or rivers, if they were preferable upon other accounts. There are, however, obstacles of a nature independent of the qualities of the steamengine, which seem to preclude the use of steam as a moving power upon canals, except in very rare instances. The agitation of the water produced by any impelling power which acts in the manner of paddlewheels or oars, as at present constructed, is found to be very destructive to the banks. Attempts have been made to remove this inconvenience by placing a paddle-wheel in the centre of the stern, acting as much as possible in the middle of the canal; and various contrivances have been suggested for feathering the paddles, so as to cause a diminished agitation in the water. None of these contrivances have, however, succeeded; a nd, except in the great ship canals in Scotland, steam-boats have not been generally adopted.
One of the principal causes of the advantage which steam posseses over horse power, arises from the circumstance that speed does not diminish efficiency. A given quantity of steam, whether produced and expended slowly or quickly, will cost the same sum, and will perform the same work; but his is quite otherwise with horses, as has been already explained. The same quantity of actual labour executed in a short space of time, requires a far greater expenditure of horse power than if it were performed at a slower rate; and hence it follows, in the comparison of the effects of steam power with that of horses, that the advantage of the former is slight, when slow rates of motion only are considered. To give the steam-engine its full advantage, if worked upon canals, it would, therefore, be necessary to propel the boat at a greater speed than 2½ miles an hour,—the rate at which horses can work with the greatest effect. But here again an obstacle is interposed, depending upon the nature and structure of canals. A boat moving in a canal at a higher rate than 3 miles an hour, is found to produce such a surge and motion of the water, as to injure or even destroy the embankments, unless in canals of considerable width, such as the great Caledonian Canal. Were the steam-engine, therefore, applied to propel boats upon any of the ordinary canals, it would be necessary to limit the speed to that rate at which the steam-engine competes with horses with the least advantage. It is probable that, even under these circumstances, in most situations, steam power would be found more economical than that of horses. As the other circumstances, however, already alluded to, have hitherto excluded the use of the steam-engine upon canals, and, as far as I can now see, are likely to continue its exclusion, it is superfluous here to discuss the comparative merits of its power and that of horses. We must for the present regard the latter as the only power practically available upon canals for general use, and this power generally limited to a speed not exceeding 3 miles an hour.
It is not necessary here to notice particularly the application of a steam-engine upon great rivers and ship canals. There, it has no rival as a moving power, at any speed within twelve miles an hour, and its application is not restricted by any of those difficulties which attach to ordinary canals.
There are two methods by which the steam-engine may be applied to a great advantage to draw or impel carriages on At certain stations, placed at convenient intervals, there may be fixed steam-engines which act upon ropes extending along the road; and by working these ropes, may draw any wheel carriages which are attached to them. In this manner, carriages may be drawn from station to station, on a straight line of road upon which engines of this kind may be provided. The other method in general use consists in drawing the carriages by a travelling steam-engine, which impels itself together with its load. In the former method, large and powerful low-pressure, or condensing engines, are admissible; because they are stationary, their weight and complexity are not limited, and a sufficient supply of water may generally be provided at the several stations. The travelling steam-engines must, however, be light in their weight, small in their bulk, and simple in their structure. For this reason, a road. as well as because the transport of a large quantity of cold water could not be conveniently effected, high-pressure engines alone are preferable to all others for locomotive purposes; and even with these, it is necessary to resort to extraordinary means to combine sufficient powers of steam for the loads that it is necessary to draw, with a sufficient heating power to produce that steam, in the quantity necessary to maintain the speed at which the engine is capable to travel.
A travelling steam-engine is placed like an ordinary carriage, upon four wheels. The axle of one pair of these wheels is furnished with cranks, as already described; which cranks or driving wheel are worked by the pistons of the cylinders of the engine, so as to keep the axles in a constant state of rotation. Upon this axle the wheels are fixed so as to be incapable of turning independent of the axle, as the wheels of a carriage do; consequently, when the engine causes the axle to revolve, it necessarily causes the wheels fixed upon that axle also to revolve. The pressure of the wheels upon the road gives them a certain degree of adhesion, so that they are incapable of slipping. When the axle is turned by the engine, the carriage must therefore advance as the wheels revolve. One stroke of the piston corresponds to one revolution of the wheels; and in one revolution of the wheels, the carriage advances through a space equal to their circumference; consequently every stroke of the piston propels the carriage along the road, through a space equal to the circumference of the working wheels. It is apparent, therefore, that the speed or rate of motion of the carriage will depend on the rate at which the boiler is capable of supplying sufficient power of steam to the cylinder.
There are two distinct methods of placing the loads upon the engine; one, by placing it on the same carriage with the engine itself; and the other, by causing the carriage which bears the engine to drag after it other carriages containing the load. The latter method has been invariably adopted upon railroads. On common roads, some projectors prefer the one method, some the other. Whichever method be adopted, the pressure necessary to be exerted on the piston, must depend upon the power of the steam to overcome the resistance which the load opposes to its progressive motion upon the road; and this resistance again depends partly on the nature of the road and its inclination to the level, and partly on the weight of the load. Upon level railroads, as has been already observed, the same power is capable of impelling at least twelve times as great a load as upon a good Macadamised turnpike road.
The combination of lightness, power, and speed, which is indispensable to the efficiency of travelling steam-engines, requires that the boilers should be so contrived that a small quantity of water should be exposed to a great heating power. As the furnace must necessarily be small, the fuel must, therefore, be kept in fierce combustion; and for this purpose a powerful draft of air must be maintained through it. The difficulty of accomplishing this, long obstructed the progress of this invention; but a fortunate application of the waste steam which escaped from the cylinder, after having urged the piston, and which had been previously useless, solved this important problem. This steam was carried off by the chimney of the engine; and being introduced into it through a confined jet presented upwards, formed a powerful steam-blast up the chimney, and a draft of corresponding power was consequently produced through the furnace. This admirable contrivance forms one of the most important features in the recent improvements of locomotive engines. Its efficiency will be more fully appreciated when it is considered, that in proportion to the velocity of the engine, the discharge of steam from the cylinder will be more rapid, and thus the draft in the furnace will be most powerful at the moment when its power is most wanted.
An unlimited power of draft in the furnace being thus obtained, a fire of adequate intensity may always be supported. The next object is to expose the water to the action of this fire, under the most advantageous circumstances. A great variety of contrivances have been from time to time suggested for the attainment of this end. All, however, consist in subdividing the water by some means or other, so as to expose an extensive surface of it to the action of the fire. Some have distributed the water in small tubes, through and around which the fire plays. Others have disposed it between thin plates of metal, upon the external surface of which the fire acts, so that a number of thin sheets of water are exposed upon both sides to the action of the fire. Others again have proposed to place the water between two cylinders, nearly equal to one another, so as to have a thin cylindrical shell of water between them, the fire acting both inside and all round the cylinders. A number of such concentrical cylindrical shells of water may thus be exposed to the action of the furnace; the space between the concentrical cylinders forming the flues. Others propose to place the water in flat horizontal pans, disposing it in thin strata, the lower surface of which should be exposed to the action of the fire, the upper forming the evaporating surface. It would be impossible, were it even expedient, within the limits of this article, to explain the details of all these various contrivances. I shall, therefore, confine my observations to one or two of those which have either come into practical use, or which I consider to be on the point of doing so.
The locomotive engines constructed by Mr. Stephenson, and used on the Liverpool and Manchester railroad, consist of a cylindrical boiler placed upon its side; the furnace being at one end, and the chimney at the other. This boiler has circular ends, and its length (seven feet) from end to end, is traversed by about 100 copper tubes, each an inch and a half in diameter. These tubes form the only communication between the furnace and the chimney; and therefore through them the draft from the furnace towards the chimney must pass. The furnace is a square chamber, of considerable size, the back of which is connected with the end of the boiler. The sides and top, as well as part of the front, are formed of a double plating of iron, with a small intermediate space. The bottom contains the grate-bars which support the fuel. The space between the plating just mentioned, is filled with water, which communicates with the water in the boiler; and every part of this intermediate space being below the level of the water in the boiler, must necessarily be always filled.
Under these circumstances it will be apparent, that the surface of fire on the grate-bars is upon every side surrounded by a sheet of water, upon which its radiant heat acts. The blast of air which rises through the grate-bars, and passes through the burning fuel, is carried by the draft through the 100 tubes which traverse the boiler longitudinally. This highly heated air, in passing through the tubes, imparts its heat to the water in the boiler by which they are surrounded; and when it issues into the chimney, it is reduced to nearly the same temperature as the water itself. By these means, the greatest portion of the heat, whether radiated by the fire, or absorbed by the air which passes through it, is imparted to the water; the shell of water surrounding the furnace receiving the radiant heat, while the water surrounding the tubes and the boiler receives as large a portion of the heat absorbed by the air as can be communicated to it. The shell of water surrounding the furnace upon which the heat acts being below the level of the water in the boiler, and being generally heated somewhat more highly than that water, has a tendency to ascend, a current is accordingly established, running from the intermediate space surrounding the furnace to the cylindrical boiler, and a corresponding returning current must of course take place. Thus there is a constant circulation of water between the spaces surrounding the furnace and cylindrical boiler.
A close chamber of some magnitude is constructed at the opposite end of the boiler under the chimney, and in this chamber are placed the working cylinders. In the earlier engines used on the railroad, these cylinders were placed outside the boiler, and were consequently exposed to the atmosphere. A considerable portion of heat was thus lost, the saving of which was completely accomplished by transferring the cylinders into the chamber under the chimney just mentioned. This chamber receiving in the first instance the hot air which rushes from the tubes, and the exterior surfaces of the cylinders being exposed to its action, their temperature is maintained at nearly the same point as the water in the boiler.
These engines are placed upon four wheels, the greater part of the weight, however, usually resting upon two. Thus in an engine weighing eight tons, five tons rest upon the large wheels, and three on the less. The axle of the greater wheels is cranked, and they are kept in a state of rotation by the engine. In some engines, however, the pistons work the four wheels, and in this case the wheels are of equal size, and subject to equal portions of the weight.
At the time when extensive lines of railroad are in progress, calling into action many millions of capital, and the welfare and property of thousands, and when other lines not less extensive are in contemplation, it would be extremely desirable, were it possible, to give an estimate of the regular expense of maintaining and working a railway, which has been already successfully established, and the advantages arising from it as a great comercial speculation. But there are circumstances attending the Liverpool railway which render such an estimate impracticable. The proceedings of the company and their engineer, from the moment when the earth was first opened on the projected line, to the present time, cannot be justly regarded in any other light than as a series of experiments, each successful in itself, but each only the forerunner of improvements by which the previous methods and expedients were superseded. And this was naturally to have been expected, when it is considered, that no great experiment of this nature was ever before tried; for although railroads, to the number of about sixty exist throughout the kingdom, the majority of which are of earlier date than the Liverpool line, yet they were worked chiefly by horses; and though, in a few cases, locomotive engines were used, their application was never thought of in the manner and to the extent or advantage to which the ambition and enterprise of the Liverpool projectors have aspired. Knowledge was therefore to be gained; and gained it could not be, but at the price of that succession of comparative course of human experience.
It is well known, that in order to stimulate the enterprise of the country, and to ascertain the form of engine best adapted for their purposes, the directors of the company, early in the year 1829, proposed a prize of 5001, for the best locomotive engine, which should be produced under certain stipulated conditions. This proposal led to a public trial, at which engines of three distinct forms were produced; one by Mr. Robert Stephenson, son of the engineer of the railway; another by Messrs. Braithwaite and Ericson; and a third by Mr. Timothy Hackworth. Two others were present, but did not undergo any part of the trial. Mr. Stephenson's engine fulfilled all the conditions proposed by the directors, and underwent the whole of the trial: the other two also fulfilled the conditions, but failed, from divers causes, before undergoing that experimental test which was required by the judges. The prize was accordingly with justice awarded to Mr. Stephenson. Jun.
There can be no doubt that this method of exciting competition produced a favourable effect at the time; and most probably the enterprise would not have commenced with the same degree of success without some such expedient. Nevertheless, it has had also some injurious consequences. It will be easily understood, that an engine may possess great powers and capability of improvement, and yet fail upon a single trial; or it may fail even from accidental causes, unconnected with any defect either in its principle or in its details. The complete success of the engine furnished by Mr. Stephenson appears at once to have fascinated the directors; and whether intentionally or not, the fact is indisputable, that the monopoly of engines has ever since been secured to the manufacturer of this particular form of machine. Even when Mr. Stephenson was unable himself to supply engines as fast as the company required them, and other engine-makers were employed, it was under the most rigorous conditions, to construct the engines upon the same principle and in the same form, or nearly so, as that which Mr. Stephenson had adopted.[4] Experience, the great parent of all invention and improvement, so far as the railroad afforded it, has thus been exclusively confined to one particular form of engine. Under the influence of this, a succession of improvements, as might have been expected, have been made by the ingenious inventors of the engine above described. These improvements consist partly in the relative proportion and strength of the parts, and partly in the arrangement of the cylinders and their action upon the wheels; but all have been suggested by the results of experiments, upon such a scale as was altogether unattainable, by any part of the vast stock of national talent excluded from the road by those measures of the directors, which limited the engines employed to a single form, without deviation. The whole enterprise of the country was therefore paralysed, in as far as the powers of this road were concerned; with the exception of one individual, who was fortunate enough to obtain a field of exertion, which it must be admitted lie did not fail adequately to improve. It is true that upon some occasions the Directors have signified that they were willing to receive proposals for engines of other forms, but upon the condition that their performance should be in no degree inferior to those of the engines used on the road at the time of making such proposals. It is scarcely necessary to point out the impolicy and injustice of such conditions, when I consider the advantage possessed by one engineer, in having the exclusive experience of the road as his guide. It would perhaps have been not only a more liberal, but a more wise policy in the Directors, to have encouraged the inventive genius of the country, by affording it in some degree those opportunities and advantages which the possession of so grand an instrument as their railroad placed in their hands; and this might have been done in such a prudent way as would not have exposed them to the charge of unduly rendering the property of the Company subservient to the visionary speculations of unpractised persons.
At the commencement of the undertaking, the fuel consumed was at the rate of about 2 lbs, per ton per mile; and the engines were considered as suited to draw about three times their own weight. Improvements, however, have been successively introduced during the last two years, which have reduced the consumption of fuel in a very considerable degree. I am not able to speak of the actual consumption of fuel in regular work, at this moment. However, several experiments, in which the consumption of coke was actually observed; and these experiments, made at different periods, may be easily compared one with another. In the experiment made with the Rocket, constructed by Mr. Stephenson at the opening of the railway, the consumption of fuel was found to amount to 1¼ lb, of coke per ton per mile, exclusive of the weight of the engine and tender. This rate of consumption was reduced, by increasing the number of tubes in the boiler and other means, to 1 lb, per ton per mile; and more recent experiments have been made, which I have had the advantage of witnessing, and in which a further reduction was accomplished.
The load which the engines are capable of drawing in proportion to their weight, has also been found greatly to exceed that which at first was thought to be the limit of their power. An engine weighing 8 tons is now in ordinary cases loaded to the amount of about 100 tons gross; but even this is below its power of traction; as will appear by the following experiments which were made on the railroad during the present year.
"No. 1. Engine, Victory; weight 8 tons, 2 cwt., of which 5 tons, 4 cwt. are on the working wheels; cyl nder, 11 inches; stroke, 16 inches diameter; working wheels, 5 feet."
"5th May, 1832. This engine drew from Liverpool to Manchester (30 miles) in 1 hour and 34 minutes, 20 loaded waggons, weighing gross, 92 tons, 19 cwt. 1 quarter; consumption of coke, 929 lbs. net; was assisted up Rainhill plane, 1½ mile, by the Samson.
Speed on the level, 18 miles an hour. Fall of 4 feet in a mile, 21.50. Fall of 6 in do. 25.50. Rise of 8 feet in do. 17.03. Level sheltered from wind 20 "N.B.—Moderate wind direct a-head; slipped on Chat-moss, and retarded two or three minutes. "8th May, same engine drew 20 waggons; weight, gross, 90 tons, 7 cwt. 2 quarters, to Manchester, in 1 hour and 41 minutes; stopped to water, &c. 11 minutes, half way, not included in the above; consumption of coke, 1,040 lbs., under the same conditions as first experiment.
Speed on the level, 17.78 miles an hour. Fall of 4 feet in a mile, 22 5 feet do., 22.25 Rise of 8 feet do., 15 "N.B.—High wind a-head; connecting rod worked hot, being keyed too tight; on arriving at Manchester, pistons found so loose in cylinders that steam blew through, owing to the extra strain up hill.
"On the 29th of May, the engine called the Samson (weighing 10 tons 2 cwt., with 14 inch cylinders, and 16 inch stroke; wheels, 4 feet 6 inches diameter, both pair being worked by the engine; steam, 50 lbs, pressure on the square inch of the piston 130 tubes), was attached to, with 50 waggons, laden with merchandise, net weight 150 tons. The engine, with this load, travelled from Liverpool to Manchester, 30 miles in 2 hours and 40 minutes, exclusive of delays for oiling and watering, &c., being at the rate of nearly 12 miles an hour. The speed varied according to the inclinations of the road. Upon a level it was 12 miles an hour; upon a descent of 6 feet in a mile, it was 16 miles an hour; upon a rise of 8 feet in a mile, it was about 9 miles an hour. The weather was calm, the rails very wet, but the wheels did not slip, even in the slowest speed,—except at starting, the rails being at that place soiled and greasy with the slime and dirt to which they are always exposed at the stations. The coke consumed in this journey, exclusive of what was used in getting up the steam, was 1762 lbs., being at the rate of a quarter of a pound per ton per mile."
From these experiments, compared with former results, it must be apparent in how progressive a state the art is, of manufacturing and working locomotive engines; and how difficult it is in such circumstances to make any estimate which may form a fair ground of calculation in future undertakings. When the advancement of this art is so rapidly proceeding a major limit, beyond which the expenses cannot pass; and this limit may be readily deduced from the published half yearly reports of the Liverpool company. I consider it the more necessary to refer to these reports, and to quote their results, because of the various erroneous statements which have been put into circulation by parties who imagine they have interests counter to railways.
It appears that regular traffic upon the railway commenced on the 16th of September 1830; and a report was published of the operations for 3½ months, up to the 31st of December, 1830. It farther appears, that during that period the profits of the Company amounted to 14,432l. 19s. 5d. Hence, taking the capital invested in this work, and experiments at a million, which is very nearly its amount, the profits during the first 3 months were at the rate of about five per cent. By subsequent reports, it appears, that for the half year ending the 30th of June, 1832, the profits were above six per cent.; and for the half year ending 31st of December, 1831, at the rate of more than eight per cent. The amount of the half year terminating on the 30th of June, 1832. I believe is not yet published; but it appears from the report published in March last, that a considerable increase of trade took place in the coaching department in the twelve weeks ending the 23d of March, as compared with the corresponding period in the last year, and that a like increase was observed in the traffic in merchandise, and traffic increasing every week.
I may therefore fairly assume, that the profits upon this undertaking have not yet attained that limit at which they will probably fix themselves. The rate at which they will increase, must, no doubt, be accelerated by the improvements which are daily in progress in the art of constructing locomotive engines; and improvements which extend to every part of their operation, as well as the consumption of fuel, the wear and tear of materials, the cost of manufacture, &c. The expenses of the Company have hitherto been also increased by the circumstance of the engines being started with loads inferior to their power. This disadvantage has been lately, in a certain degree, remedied, by their combining loads of passengers and goods, in each cargo.
The name of a high-pressure engine was long in this country a bugbear, and a sound connected with some undefined and unintelligible notion of danger. It would be very easy to show that the causes which produce the explosion of boilers are not confined in their operation to high pressure engines; that they depend upon circumstances altogether unconnected with the temperature or pressure at which the steam is raised; and, consequently, that such accidents when they do occur, which is very rarely, are as likely to happen in the one class of engines as the other. But the best and most intelligible proof which can be given of the groundlessness of this apprehension, is the fact, that for a period of nearly three years, during which travelling and traffic have continued on the railway, and numerous high-pressure engines have been constantly at work upon it, no accident has ever yet occurred from explosion or from any cause depending on the pressure of the steam. Boilers have burst, it is true; but in bursting they have been attended with no other effect than that of extinguishing the fire, and suspending the journey. Two or three accidents to passengers have occurred, but in every case they have been produced by the want of the most ordinary care on the part of the sufferer, and in only one instance have they been fatal, although nearly a million of passengers have travelled upon the road. If the number of accidents which have occurred be compared with those which occur upon a mail-coach road with the same number of passengers, the comparison will exhibit in a clear light the superior security for life and limb afforded by the substitution of steam-engines on railroads for horses.
As might be expected under such circumstances, upon occasion of trials of this kind, complaints have been made, and charges of unfair proceedings have been brought against those employed upon the road. The engine men of the Company, and those under them, it is said, upon such occasions screwed down or overloaded the safety-valves of Mr. Stephenson's engines, with a view to give them an unfair advantage; and have secretly inflicted injuries upon those competing with them, for the purpose of disabling them, or impairing their performance. I believe that such complaints have come before the directors, and that they have been found not always groundless. The offender, it is said, has been sometimes dismissed.
I now take leave of this topic, recommending to the directors to consider whether the continuance of the system complained of be consistent with the real interests of their constituents; and the genius of the country, and bringing it to bear upon one of the noblest undertakings which England or any other country in the present or any former age has beheld;—by considering whether it be not advisable not only to be free from suspicion, but to be free even from the appearance of it;—by considering whether it be expedient that the same individual who is the engine maker should be the engine judge; and whether the directors, being themselves carriers, should not exercise those functions with great caution and prudence, in which their peculiar situation renders it necessary that they should act as judges over other carriers competing with them. The conduct of the directors may have been unimpeachable;—the conduct of the engineer may have been free from blame. I make no charge against either; but the public generally will never believe in the purity of the one, or the blamelessness of the other, until the strong appearances which circumstances of their own creating have raised against them be removed. The next step in the progressive improvement of the art of inland transit, is the adaptation of the steam-engine to propel carriages on common roads. The practicability and advantage of the same power on railroads leads necessarily to enquire, whether there is any and what difference in the quality of railroads and turnpike roads, which would render a power of traction so profitable on the one impracticable on the other. I have seen that the resistance to the rolling motion of a carriage on a well-constructed turnpike road may be fairly estimated, cæteris paribus, at about twelve times the resistance on a railroad. It follows, therefore, that whatever be the power of traction used, it will be capable of drawing a load of proportionally less amount on the turnpike road. The surface of a turnpike road is necessarily more uneven than that of a railroad; and, therefore, subject to greater variation in the resistance which it offers to the power of traction. A level railroad may be considered as presenting a nearly uniform resistance; and whatever impelling power is used upon it, it need be susceptible of no change in its intensity. The want of the same evenness on the surface of a turnpike road, the different states of repair in which different parts of it must necessarily be at any given time, but, above all, the fact that the rolling of the carriages themselves is the means by which the road is for the most part formed, consolidated and rendered smooth, make it necessary that any power of traction used upon it shall be susceptible, as occasion may require, of considerably varied energy. A newly made Macadamised road, presenting a surface of loose broken stones, offers a resistance several times greater than the same road when its surface is worn smooth. Now, as parts of every road are subject occasionally to be in this state, that relation between the power of traction and the load must be observed, which is suited to the most difficult part of the road, as well the effects of a thaw, after a severe frost to be encountered.
I have explained that the effect of incurvations on a road will obstruct the speed, whether it be a railroad or a turnpike road, but that the increased resistance offered by them on turnpike roads, bears a much smaller proportion to the resistance on the level, than is the case in railroads. The increased power, therefore, required by them, is not so great proportionally on turnpike roads as on railways; and it may be doubted, whether such increase on the regular mail-coach roads will often exceed that which is necessary to overcome the inequalities of resistance presented by the causes already explained on levels.
From the peculiar mode in which the steam-engine is used in propelling carriages, it follows that no power of traction, however intense, can be available beyond the adhesion of the impelling wheels with the surface of the road, which amount to double the weight of the carriage propelled; since that adhesion forms as it were the fulcrum or purchase by which the moving power is enabled to propel the carriage. Like the resistance to the rolling motion, this adhesion is subject to much greater variation on common roads than on railroads; and to ascertain its practical power, that point must be taken at which its efficiency is at its lowest limit. This power of adhesion was Jong supposed to be so slight on common roads, that no considerable load could be impelled by its means. But more recent experience has proved that it is abundantly sufficient, under all ordinary circumstances, not only to propel the carriage, whose load rests upon the working wheels, but also to drag other carriages loaded in its train, ten times its weight on a railroad.
An obstacle was also anticipated to the practicability of this adaptation of the steam-engine, from the supposition that carriages thus constructed and propelled would occasion so rapid a wear and destruction of the turnpike roads, as to render the expenses of the repairs greater than any advantages to be derived from them could compensate. This objection, however, has also proved illusory. On the occasion of a steam-carriage being worked on the road between Gloucester and Cheltenham, for some months in the year 1831; those interested in turnpike roads procured the legislature to pass various acts of parliament, imposing prohibitory tolls on carriages propelled by machinery. A petition for the repeal of those acts was immediately elicited from Mr. Gurney, then the most enterprising and successful of the steam- carriage projectors. A committee of the House of Commons was appointed to receive evidence and to report on this petition; the result of which, was the report to which I have already alluded, and the consequent repeal of the prohibitory toll acts. By the evidence laid before this committee it was satisfactorily established, not only that carriages propelled by steam were not more injurious than carriages drawn by horses, but that they were considerably less so. To adapt horse coaches to move with the speed necessary for travelling, and for despatches, the tires of the wheels should be of very limited breadth; and latterly, they are even constructed with a round surface, instead of a flat one, towards the road; the section of the tire by a plane through the axle, and at right angles to the wheel, being a semicircle or elongated semi-ellipse. In either case such a wheel must cut up the best and hardest road. The wheels of steam-carriages on the other hand, are most efficient, when constructed with a broad tire, the tires never being less than four or five inches in breadth; and, according to the plans of some projectors, extending even to six or eight inches. The tires being truly cylindrical and not dished, the wheels act upon the road in the manner of rollers, and, instead of wearing it, rather tend to consolidate and render it smooth and firm. Thus a steam-carriage, compared with a horse carriage, in as far as relates to the wheels only, is much less injurious to the road, if, indeed, it can be said to be injurious at all. But a stronger testimony is furnished in favour of steam-carriages by the fact established before the committee, - that the principal part of the wear of roads proceeds, not from wheels but from horses. Indeed, a very slight consideration might have caused this fact to have been foreseen. If the nature of the action of a wheel 2½ inches broad rolling along the road, be compared with the pounding and digging of the iron-shod feet of horses, the question will be readily understood.
From what has been above stated, the qualities necessary to adapt a locomotive engine to propel carriages on turnpike roads may be easily inferred. Since the resistance of a given load to a propelling power is greater in a twelve-fold proportion than on a railroad, it follows, that with the same power the load drawn must be proportionally or twelve times less. But since a part of this load is the weight of the engine itself, and since this weight must bear some proportion to the entire load, it follows, that engines of equivalent power, to be adapted to common roads, must be lighter than those used on rail roads. But again, this consideration extends to the fuel and water as well as to the engine and boiler. Since a less quantity of water and fuel can be transported, a fresh supply must be taken in at shorter stages, of 6 or 8 miles. The railroad engines can travel about 20 miles without watering, and 30 without taking in fuel on a level railroad.
The steam coaches on common roads must be supplied with water and fuel every stage of 6 or 8 miles. The furnace being necessarily smaller and less powerful than those used in locomotive engines on railroads, the steam can be generated with sufficient abundance and rapidity, only by exposing to the action of the fire a much greater quantity of surface, in proportion to the whole quantity of water, than is attempted in engines on railways; and it is in the attainment of this object that the ingenuity of steam-carriage projectors has been for the most part displayed. It may, therefore, be interesting and useful at the present time, when we are on the eve of witnessing four attempts of steam-carriages on common roads, and when the practicability of the project has been recognised, and the conditions of its tolls regulated by the legislature, to describe one or two of those machines which seem to be most ripe for practical operation.
The earliest and most enterprising projector in this adaptation of the powers of the steam-engine was Mr. Goldsworthy Gurney. To his perseverance and sagacity the public are indebted for the removal of many erroneous prejudices, which long obstructed the progress of this invention, and discouraged the mechanical skill of the country from taking a direction so beneficial in its effects as this improvement in transport. By journeys, in an experimental carriage, between London and Bath, and frequent trips in various directions near the metropolis. Mr. Gurney gave incontestible experimental proof of the practicability of impelling a carriage on a turnpike road by a steam-engine, with a speed equal to that of the swiftest four-horse coach. He proved, also, that the objection was groundless, that the working wheels would slip round without propelling the carriage; and that a similar objection, that such a carriage could not be driven up considerable hills, was also unfounded. His experimental carriage, though extremely rude and ill-constructed, and subject to many defects, ascended without difficulty, all the hills between London and Bath, as well as the hills on various roads round London, including Stamford Hill, and the hill which ascends from Kentish Town to Highgate, called old Highgate Hill. The last ascent rises at the rate of one foot in twelve from the foot to the corner of the terrace at Holly Lodge. From this point to the top, it is more steep, rising one foot in nine. So steep a hill as this never occurs on any of the lately constructed mail-coach roads in England.
These experiments took place about the year 1826; since which time the engine of Mr. Gurney has undergone very considerable improvements; and this machine may now be considered to have attained a state of perfection which fits it for immediate use for light loads, as a means of transport for passengers and goods, for short stages, but never can pay its expense for construction and conducting it like all the others, but on railroads it can be used to advantage.
The grate-bars of the furnace in this engine, are a series of parallel tubes stretching from the front to the back, and sloping slightly upwards. In the front these tubes are fastened in the side of a strong metal cylinder, which extends across the front under the door of the fire-place. The extremities of the same tubes at the back of the grate are connected with the ends of a corresponding series of upright tubes, which, in fact, form the back of the furnace. The upper extremities of these last tubes are connected with the extremities of a third series, which form the roof of the furnace, sloping slightly upwards from the back towards the front. In the front, their extremities are fastened in the side of a strong metal cylinder, which extends across the front of the fireplace over the fire-door, and corresponds with the other cylinder already described. These two cylinders are connected by two large upright metal tubes, one placed at each side of the fire-door, and forming the sides of the front of the furnace. From this description, it will be easily perceived, that the tubes and cylinders which surround the furnace, afford the means of a complete circulation round it, communicating freely with each other at their several points of connection. The cylinder, which is placed above the fire-door, communicates by large tubes with another vessel, which is removed from the furnace, and called a separator, for a reason which will presently be explained.
Now, suppose the cylinders above and below the fire-door, and the system of tubes surrounding the furnace, which communicate with them, to be filled with water, and a quantity of fuel in a state of combustion placed upon the tubes at the bottom of the furnace which form the grate bars. The heat radiated from this fire, plays on every side upon the tubes forming the back and roof of the furnace,—on the cylinders already mentioned above and below the fire-door in front,—and on the upright tubes at each side of the fire-door. Whatever quantity of heat may pass downwards is received by the water in the tubes forming the bars of the grate. The spaces between the tubes forming the roof and back of the grate are stopped; with the exception of a small space at the lowest part of the back, where the spaces between the tubes are open, and lead to the flue which carries off the draft. This flue passes immediately behind the tubes in the back, and is conducted over the tubes in the roof. The air, which, passing through the fuel, maintains it in vivid combustion, and becomes intensely heated, is thus conducted in contact with that side of the tubes forming the back and roof, which is not exposed to the action of radiant heat. As it passes, it imparts a portion of its heat to the water in these tubes, and finally issues at a reduced temperature into the chimney. Such is the contrivance by which every portion of the caloric given out by the combustion of the fuel is communicated to the water.
The water in the tubes forming the roof of the furnace, being more advantageously exposed to the action of the fire, becomes more intensely heated, and acquires a tendency to ascend. It is to give play to this tendency, that the tubes in the roof are placed in a direction sloping upwards, as already described. The position of the tubes forming the grate-bars is attended with a like effect. When the engine is in operation, therefore, the water in the boiler is kept in a state of prodigiously rapid circulation round the furnace. The water in the tubes forming the grate-bars, rushes constantly from the front towards the back of the furnace; thence it ascends with rapidity through the upright tubes at the back, and passes from them with equal speed through the tubes in the roof, into the cylinder placed above the fire-door,—a corresponding descending current being continually maintained from this cylinder through the vertical tubes at each side of the fire-door. The steam bubbles which are formed in the tubes surrounding the furnace are carried with this circulating current into the cylinder above the fire-place; whence ascending by their levity, they pass into the vessel already mentioned called the separator. The boiler is kept continually filled by a force-pump, which injects water into one of the cylinders which surround the fire-door.
One of the most obvious advantages of this arrangement is, that every part of the metal exposed to the action of the fire, not excepting the grate-bars themselves, is in contact with a rapid stream of water. As fast, therefore, as the metal receives heat from the fire it imparts that heat to the water; and can never itself receive that excessive temperature which would cause its destruction by burning; besides which, all the heat which would thus be expended in producing an injurious effect is here consumed in producing steam. The form of every part of the boiler being cylindrical, is that which, mechanically considered, is most favourable to strength. I cannot conceive the possibility that a boiler of this kind, properly constructed, and previously proved in the usual way, could, under any supposable circumstances, explode.
When the steam passes from the cylinder above the fire-door to the separator, it is charged with water suspended in it in minute subdivision, an effect called by engineers priming. If the water thus mechanically combined with the steam, were allowed to pass through the engines, several injurious effects would be produced, among which may be mentioned the waste of all the heat which that water would carry with it. This is a defect common, in various degrees, to all the locomotive engines, except the one now under consideration. The purpose of the separator is to disengage or separate the water from the steam in which it is mechanically suspended; and this is accomplished merely by allowing it to descend by its gravity to the bottom of the separator. It collects there, and is thence conducted back to the boiler to be circulated again.
The next contrivance which claims notice in this machine is the method of blowing the fire. I have already explained the means adopted in the railway engines for accomplishing this, by throwing the waste steam from the cylinders into the chimney. This, however, is attended with a puffing noise, arising from the sudden blasts of steam ejected by the alternate strokes of the piston, and which is increased by the form of the chimney, and the aperture by which they escape. Such a noise would be inconvenient and objectionable. Yet to put aside the use of the waste steam in the production of draft, would be to sacrifice the greatest excellence attained in the construction of steam-engines since the discovery of separate condensation; beside which this important improvement may very justly be placed. The difficulty has, however, been overcome without the sacrifice of so great an advantage. Instead of allowing the puffs of steam ejected from the cylinders to pass directly to the flue, Mr. Gurney conducts them to a chamber or receptacle, which serves a purpose analogous to that of the chamber between the upper boards of a forge bellows, converting the intermitting puffs into a steady and continuous blast. The steam compressed in the chamber just mentioned, escapes in a number of small jets presented upwards in the chimney; creating a constant and effective draught through the fire, unaccompanied by any noise.
Such are the more obvious qualities of Mr. Gurney's steam-engine, of which it would not be consistent with the limits of this article to give a more detailed analysis, but which the reader will find more fully described in several published works.
I am aware of but three other locomotive engines which are in a sufficiently forward state to give early promise of being practically exhibited on the road. These are the inventions of Dr. Church of Birmingham, Mr. Hancock of Stratford, Essex, and Mr. James Fraser, Hackney Road, London.
In the engine of Dr. Church, a circular fire-grate is surrounded by a number of upright tubes about three or four feet in height, and bent at the top, so as to return downwards in a siphon form. These tubes are made to serve the purpose of flues, in the same manner as those which traverse the Manchester engines. They are contained within other tubes of somewhat great diameter, so that a small space is included between the two concentric cylindrical surfaces. This space being filled with water, the fire is surrounded by a vast number of thin cylindrical shells of water, the exterior surfaces of which are exposed to the action of radiant heat, while the interior surfaces receive heat from the air which has passed from the fuel, and is carried off into the atmosphere.
While the subdivision of the water in its exposure to the fire is effected by Dr. Church, by reducing it to thin cylindrical shells, the same end is attained by Mr. Hancock, by arranging it in thin flat plates. His boiler consists of a number of thin plates of iron, placed side by side, at a distance of about an inch asunder. The water is contained between every alternate pair of plates, whilst the fire acts between the intermediate ones. It will be seen that in each case a small quantity of water exposes a very extensive surface to the fire. Mr. Hancock's arrangement, however, is said to have obvious defects. Its form being that of flat planes, exposed to a bursting force at right angles to them, is that which of all others is least conducive to strength; and although, from peculiar circumstances attending this boiler, the fact of its bursting may not be attended with danger, yet its liability to such an accident must be attended with great inconvenience, and cannot be regarded otherwise than a most fatal defect. Another defect, not less important is, that a large portion of the metal exposed to the action of fire contains steam and not water, a circumstance which should never be permitted in any boiler,—but which is utterly destructive in boilers exposed to extremes of temperature and pressure. The boiler of Dr. Church seems not to be liable in the same degree to these objections; but I cannot speak respecting it with the same confidence, as the specification of his patent has not yet been enrolled, neither has Mr. Fraser's.
In both these boilers, the draft is produced by a fanner worked by the engine. The inferiority of this to the steam draft, and the great extent to which it must rob the engine of its power, are so obvious that I need not here enlarge upon them.
When it is considered that seven years have now elapsed since the practicability of propelling a carriage on a common road by steam was established by incontestible experiment, it will naturally be enquired, why in a nation celebrated over the world for its mechanical skill and commercial enterprise, and abounding in capital, the project has not yet attained a more advanced stage? The facts detailed in the pamphlet of Mr. Gurney, the title of which is placed at the head of this article, will furnish a solution of this question satisfactory to the reader, and little creditable to some parties, whose conduct is there brought before the public.
It appears that after several years of indefatigable exertion, during which he had to encounter and refute the innumerable objections urged against the scheme,—such as the expense, the public annoyance, the removal of horses from employment, the putting of coachmen, &c., out of bread, and all the hackneyed topics by which great improvements in machinery have been ever opposed,—Mr. Gurney, at length, succeeded in getting a steam carriage established as a public conveyance between Gloucester and Cheltenham in February, 1831. It commenced running on the 21st of that month, and continued until the 22d of June,—a period of four months—during which it performed the journey of nine miles between these places, a level road, regularly four times a day. It carried in this time upwards of 3000 passengers without a single accident, at a greater speed than that of horse coaches, and at half their fares. The value of the coke expended in this performance was about 50l.,—giving an annual rate of 150l, for fuel. A horse coach to perform the same work, going at a rate of from eight to nine miles an hour, would have required eighteen horses constantly to be maintained.
The evidence afforded by an experiment continued for such a period was not to be resisted; and it carried conviction to the minds of those who fancied their interests would be affected by the impending change. The project was now to be opposed, not by fair objections, but by any means which unscrupulous men will resort to in a desperate emergency. Agriculturists, trustees of roads, coach proprietors, coach drivers, grooms, stable boys,—all were immediately up in arms. Not a day passed without gross misstatements being industriously and extensively circulated, with a view to deter passengers from choosing the new mode of conveyance. The continuance, however, of successful journeys giving constantly the lie to such reports, deprived them of their poison. The next measure was of a more effectually mischievous and atrocious character. On the 22 of June, a considerable space of the road, about four miles from Gloucester, was found to be overlaid with heaps of loose stones, to the depth of eighteen inches. The road at this place, and indeed generally, was at the time in the most excellent order. The horse carriages in crossing the stones thus laid down were compelled to unload; the steamcarriage, not being built with that degree of strength, necessary to encounter so extraordinary a strain, had its working axle-tree broken the second time it crossed the stones.
The purpose of laying down the stones was not to be mistaken; and the proprietor of the steam-carriage was strongly urged to adopt some legal mode of redress against the parties wilfully committing such an act for the purpose of obstructing him. In reply, he stated that he would decline any hostile proceeding, and that he "felt only pity and contempt for those who could resort to such means for preventing a great national undertaking."
He, hereupon, determined to strengthen the wheels of his carriage, so as to be enabled to encounter any similar obstacle which public or private malignity might throw in his way. His proceedings, however, were speedily arrested by the discovery that "an immense number of turnpike bills had hastily passed both Houses of Parliament, imposing on carriages worked by machinery prohibitory tolls. In some cases the tolls imposed amounted to 40s, at every gate; in others to 48s.; and in some to 68s.; and as if it were a national object to prevent the possibility of such engines being used, one of these acts applied to the road between Cheltenham and Gloucester."
"Hitherto," says Mr. Gurney, "we had met the objections and difficulties proposed, by physical demonstration; but here was a moral difficulty that could not be removed except upon full investigation. I, therefore, in August petitioned parliament; a committee of the House of Commons was, in consequence, immediately appointed to enquire into the subject. The committee, like all parties unacquainted with the real merits of the question, at first. I believe, considered the subject more visionary than real: how differently their minds were affected in the progress of enquiry may be judged of, when it is stated, that they soon applied for further powers, and deemed the matter worthy of close and deliberate investigation for three months. During that time some of the first statistical, scientific, and engineering authorities gave voluntary evidence on the subject. The Report, on the 12th of October, was brought up and ordered to be printed."
In the progress of their enquiry, the Committee extended their examination to the principal objections which had been urged to the application of steam on common roads. These were, the danger of explosion, the annoyance to travellers, the fright occasioned to horses by the noise of the machinery, and the smoke and steam which escape at the chimney. The committee state, that they are led to believe, by the result of their enquiries, that the substitution of inanimate for animal power on common roads, is one of the most important improvements in internal communication ever introduced; that its practicability has been fully established; that tolls to an amount which would utterly prohibit the introduction of steam-carriages have been imposed on some roads; that on others the trustees have adopted measures which place such carriages in an unfair position compared with ordinary coaches; and that the causes of these measures are two-fold,—1st, A determination on the part of the trustees to obstruct as much as possible the use of steam as a propelling power; and, 2d. The misapprehension of its effects on roads. The committee consider that legislative protection should be extended to steam-carriages with the least possible delay. Their Report goes on to say,—
"Without increase of cost, we shall obtain a power which will insure a rapidity of internal communication far beyond the utmost speed of horses in draught.
"Nor are the advantages of steam power confined to the greater velocity attained, or to its greater cheapness than horse draught. In the latter, danger is increased, in as large a proportion as expense, by greater speed. In steam power, on the contrary, 'there is no danger of being run away with, and that of being overturned is greatly diminished. It is difficult to control four such horses as can draw a heavy carriage ten miles per hour, in case they are frightened, or choose to run away; and for quick travelling they must be kept in that state of courage, that they are always inclined for running away, particularly down hills, and at sharp turns of the road. In steam, however, there is little corresponding danger, being perfectly controllable, and capable of exerting its power in reverse in going down hills.'
"Steam has been applied as a power in draught in two ways: in the one, both passengers and engine are placed on the same carriage; in the other, the engine carriage is merely used to draw the carriage in which the load is conveyed. In either case, the probability of danger from explosion has been rendered infinitely small, from the judicious construction of boiler which has been adopted.
"The danger arising to passengers from the breaking of the machinery need scarcely be taken into consideration. It is a mere question of delay, and can scarcely exceed in frequency the casualties which may occur with horses.
"It has been frequently urged against these carriages, that, wherever they shall be introduced, they must effectually prevent all other travelling on the road; as no horse will bear quietly the noise and smoke of the engine.
"The committee believe that these statements are unfounded. Whatever noise may be complained of, arises from the present defective construction of the machinery, and will be corrected as the makers of such carriages gain greater experience. Admitting, even, that the present engines do work with some noise, the effect on horses has been greatly exaggerated. All the witnesses accustomed to travel in these carriages, even on the crowded roads adjacent to the metropolis, have stated, that horses are very seldom, if ever, frightened in passing."
The committee conclude their report by the following summary of propositions, of the truth of which they state that they have received ample evidence:—
1. "That carriages can be propelled by steam on common roads at an average rate of ten miles per hour.
2. "That, at this rate, they have conveyed upwards of fourteen passengers.
3. "That their weight, including engine, fuel, water, and attendants, may be under three tons.
4. "That they can ascend and descend hills of considerable inclination with facility and safety.
5. "That they are perfectly safe for passengers.
6. "That they are not (or need not be), if properly constructed, nuisances to the public.
7. "That they will become a speedier and cheaper mode of conveyance than carriages drawn by horses.
8. "That, as they admit of greater breadth of tire than other carriages, and as the roads are not acted on so injuriously as by the feet of horses in common draught, such carriages will cause less wear of roads than coaches drawn by horses."
The proceedings which rendered necessary the investigation instituted by the Parliamentary Committee, and which justified that committee in reporting "that they had ascertained that a determination existed to obstruct as much as possible the progress of an invention," which they declared to be "one of the most important improvements in internal communication ever introduced," will, doubtless, excite unqualified indignation. That the half-civilised population of Ireland, after ages of misgovernment and oppression, should view with distrust the factories of English settlers, and shrink from a participation in benefits, the nature and extent of which they cannot appreciate, excites no surprise: if they obstruct or occasionally destroy these means of their own civilisation, their defence is found in the irresponsibility inferred by exclusion from instruction. That improvements in machinery, by which labour is superseded, sometimes excite to violence the lower classes of hand artisans, is a matter of just condemnation; but in this case also guilt has its palliation, in the difficulty which uneducated persons find in perceiving that the displacement of labour by machinery is only apparent, or at least temporary, and that the final and never-failing result is an increased demand for hands. The momentary distress which every great change in employment necessarily occasions in a manufacturing community is also a palliation which should not be overlooked; and it can scarcely be expected that present inconvenience will always be patiently borne by the labouring classes in the prospect of future, and as they may think, uncertain good. But we can find no such defence or palliation for the concoctors of prohibitory toll bills, and for the almost felonious conspirators against the public, who rendered impassable the king's highway, with a view to obstruct and defeat the efforts of those who endeavoured to extend the means by which science ministers to the use and enjoyments of society. The same Parliament which had been formerly misled by false statements, and entrapped into the enactment of unjust laws, soon discovered its error, and exposed the deception practised upon it, not only by retracing its steps and repealing the laws previously enacted, but by substituting for them measures of a directly opposite tendency,—extending legislative protection to the improvement which it was the object of the former enactments to crush. No doubt that the offenders will feel the rebuke implied in this proceeding; and that they will in future be deterred from resorting to modes of annoyance and obstruction, which, though they may elude the grasp of the law, cannot escape the blight of public opinion, in a country where freedom of discussion and the liberty of the press are recognised and established. I have been since informed that this invention and proceedings has proved the ruin of the ingenious Mr. Gurney, who has disposed of his carriage to Sir Charles Dance.
- ↑ I am aware that air shafts may be made, and that tunnels can be arched, in clay or sandy under strata at a great expense.
- ↑ I am not aware whether any comparative estimate has been made of the expense of original construction and repairs of turnpike roads and railroads. We suspect that the result of such a calculation would be more favourable to railroads than is generally supposed.
- ↑ Let L be the greatest load which the horse can bear without moving, and V his greatest speed without a load; then if x be any load, and y the corresponding speed, we shall have
- ↑ Mr. Bury, of Liverpool, has made some engines for the company. He has been allowed to depart from Mr. Stephenson's model in some trifling particulars.
