Once a Week (magazine)/Series 1/Volume 8/The restoration of our soil - Part 2
THE RESTORATION OF OUR SOIL.
PART II.
After all, the most convincing experiments are those which we make ourselves; and it luckily happens that the means of applying our house sewage to the soil are at the disposal of any person having gardens or pastures surrounding his own house. One of the most conclusive experiments recorded in the evidence given before the Select Committee on the Sewage of Towns is that of Philip Skinner Miles, Esq., of King’s Weston. Every resident of Clifton and Bristol knows well the mansion of this gentleman,—an old gloomy house that once belonged to the Lords de Clifford, and built by the cumbrous genius of Vanbrugh. This seat is one of the show places of Gloucestershire, and the grounds command one of the finest views in the kingdom. Vanbrugh, however, lived in the days before house drainage was discovered, and the result was that the sewage of the mansion trickled down the side of the road which led to it. This disgusting nuisance was not only offensive to the sight, but in hot weather was very offensive to the nose, and the work of drainage became one of necessity. But Mr. Miles did not content himself with building an expensive drain, but, following the lead of Mr. Alderman Mechi, he determined to collect the sewage of his house, containing thirty persons, together with the rainfall, into a closed tank containing about 7000 gallons, which he ventilated by a pipe running up the chimney, which effectually took away all smell. The sewage was conducted by pipes to about twelve acres of grass and to two acres of ploughed land, and distributed by means of a gutta-percha hose. The result is that these fields have been improved in value from 55s. an acre to 5l. 10s., whilst the produce has been immensely increased. Two crops a year, so thick that they cannot stand up, and the crop is always good if the season be wet or dry. This sewaged grass, moreover, comes in full a month earlier than ordinary grass, thus giving that “early bite,” the advantage of which all farmers so well know; moreover, the herbage is full and thick to the end of November. The cattle are ravenous after the rich succulent herbage thus produced, and will eat it immediately the dressing has been applied; and Mr. Miles tells us that the dairy-maids cannot account for the great increase of the cream which has taken place since the experiment has been in operation. This seems very like a transformation scene one sees in a pantomime, rather than reality. The foul and filthy lane, at a fairy’s touch, becomes changed to a smiling meadow; the milkmaids are overpowered by the flow of cream, and the land is burthened with its crops; the stock gets rapidly fat, and the turnips grow so quickly as to get without the reach of the “fly.” The good fairy and the appliances, in this case, consists of an old man who can dress the whole of the fields in the course of the day; and the machinery is comprised in the tank, a small conducting pipe, and a hydrant with a flexible gutta-percha hose. Well might Lord Palmerston have remarked that “sewage was only matter in the wrong place.” What Mr. Miles has done any other person may do likewise; for the expenditure is but trifling, and the effect so great that it will pay all outlay in the course of two or three years. In this case it was proved that the excreta of each person was equal to the fertilisation of half an acre of land. For some little time yet, we look to the experiments of individuals as the best means of propagating the idea; for it will take a long time to convince the municipal bodies that their sewage, instead of being a nuisance to be got rid of, is a valuable commodity to be dispensed. But more valuable still, perhaps, will be the experiments of large institutions, such as county lunatic asylums, where the cultivation of land is one of the means used to exercise and interest the patients. We are glad to find that the visiting magistrates have already experimentalised in this direction, both at Colney Hatch, and also at Hayward’s Heath Asylum; but the most satisfactory results have, we think, been obtained by Mr. Westwood, late farm bailiff to the schools at Anerly (the inmates of which are about 700); and their value depends upon the fact that the experiments were made by a gentleman who acted under government inspection, and was obliged to render exact accounts of his expenditure, and that they have a direct bearing upon the very important question of the best quantity of sewage to apply to the land. Of the 40 acres of land belonging to the school, four acres were under Italian rye grass and 12 acres were in very poor meadow—indeed, the whole estate was a stiff London clay, very adverse to good cultivation. A tank containing 12,000 gallons of sewage was erected to work this land. The rye-grass of four acres was dressed by hose and jet six different times in the year, the whole amount being about 1500 tons of sewage per acre; and the produce of these four acres fed “16 large dairy cows, one bull, and three or four head of young stock, besides three farm horses, for the summer months, or 180 days; each cow yielding on an average throughout the year eight quarts of milk per day. There was no perceptible difference in the crop over the whole four acres, all of it being as thick as it was possible for grass to stand. Therefore, taking that part irrigated with the hose and jet as keeping 10 of the cows, the produce could not have been less than 70 tons of green food to the acre every season. I believe it is generally considered that one of the large half-bred short-horn cows, giving full milk, will eat at least 1½ cwt. of green meat per day; allowing 8d per gallon for the milk thus produced, it would give 120l. as the return from these two acres, and, without deducting the expenses, 9d. per ton for every ton of sewage used. Assuming that this sewage had been delivered on the farm by a company, and charged 2d. per ton, the landlord or tenant having laid down the pipes on the farm necessary for its distribution, the expenses would stand as follows:—1500 tons of sewage per acre, at 2d. per ton, 25l.; one lad, distributing for 12 days, 12s.; rent of two acres, at 25s., 2l. 10s.; half man’s time cutting grass, milking, &c., &c., 7l. 10s.; part time of horse and cart, carting grass to sheds, 3l.; interest on cost and wear of pipes, hose, &c., 16s.: making a total of 39l. 8s., which, deducted from the 120l., would leave 80l. 12s. as the net profit upon those two acres, supposing that no other deductions had to be made for keeping the stock in the winter time.” When we hear a witness talk of producing seventy tons of green food per acre in one season, it seems so much like romancing, that we have thought it well to give his own words, and to state that, in the opinion of the Select Committee, they are entitled to “very great weight.” It must be stated, that of these four acres of rye-grass two were allowed an unlimited amount of sewage, amounting to between 8000 and 9000 tons per annum; yet they did not yield a better result than the other two acres dressed with only 1500 tons of sewage throughout the year, giving, in the words of the Select Committee, “a most conclusive proof of the uselessness of the enormous dressings recommended by some of the witnesses.” And, we may observe, not only the “uselessness” but the perniciousness of such superfluous dressings; for Mr. Westwood proves that the meadow grass, which was irrigated on the catch-water system at the rate of 9000 tons an acre, threw its sewage off by the drains almost unaltered in colour, and so strong that he thought it necessary to filter it before it flowed away into the brook, lest an action should be commenced against the institution for polluting the public watercourse. He found that the knobs of grass which lay above the general level of the field flourished quite as much as those that received the whole flow of the sewage; and he concludes that the dressings of 300 tons, once in the spring and once after cutting the first crop, would be equally effective with the largest dressings. The settlement of the question—heavy versus light dressings—is of great importance for other reasons besides the fertilisation of the land. To say nothing of the pumping expenses it will save, there is the question of keeping our water-sources pure: a matter which cannot be insured if enormous quantities of sewage were to be pumped on to the land to find its way down in a polluted state to the springs. We do not doubt that within certain limits the value of sewage-manure dressings will depend upon the degree of its dilution. A certain quantity of water is absolutely necessary to carry the fertilising particles to the roots of the plants; but what that precise quantity is we have yet to find out. Owing to the ever-varying amount of rainfall which is allowed to dilute it, no exact calculations can be made of its value—indeed, the excreta of each person are estimated by two individuals in the report variously at 1s. 9d. to 1l. per annum: a divergence which results from the absurd practice of allowing the rainfall to mix with the house sewage, which would otherwise be represented by a tolerably invariable quantity to each inmate. The evidence of Lord Essex, who has used the sewage manure extensively, is to the effect that it is applicable to all crops, and that it may be applied with advantage at all times of the year, excepting during hard frosts; but that it is expedient that the agriculturist should have the full command of the sewage, so that he may apply it when and in what quantities he likes. This points to the system of irrigation by pipes and hose and jet as the most convenient method of distribution. Mr.; Tufnell, one of Her Majesty’s Inspectors of Schools, who reports with respect to the rigid exactitude of the experiments carried on at the Anerly schools under his inspection, states that he found the second crop produced by the sewage was far more productive than the second crop produced by guano, a statement which accords with the assertion of all scientific agricultural chemists, that while guano and other manufactured manures exhaust the soil by over-stimulation, sewage manure permanently improves it.
We trust this statement will restore confidence to those who have been frightened by a letter in the “Times” lamenting the exhaustion of our vegetable mould under its guano treatment, and also the following remarks of the Committee, which will, doubtless, give a clue to the extraordinary evidence of chemists and others interested in the sale of foreign manures:—
If the sewage of our cities and towns were utilised to the best advantage over suitable areas, it is evident that, as on the Court farms, little or no imported manufactured manures would be used; this would greatly limit the area now supplied by such manures, and would therefore reduce the profits of all those engaged in the importation, manufacture, or sale of manure.
There seems to be a general impression that, as far as municipal experiments are concerned, those towns which lie high are sure of the most successful results, inasmuch as they possess the power of distributing the sewage by gravitation, thus getting rid of the cost of the pumping expenses and the fixed machinery. There are several such towns admirably situated. Thus Launceston, in Cornwall, could command a flow to at least 1,000,000 acres, from its high level; Malvern, again, overlooks the valley of the Severn, and has a gentle fall to that river for miles. The best portions of Bath are built upon the hills overlooking the Avon; and a very large population is located on the hills on which Bristol is built, much of the sewage of which flows into the stagnant floating harbour, rendering it one of the most unhealthy places in the kingdom, according to the returns of the Registrar-General. In all these places, and indeed in many towns where a flow of the sewage as small as 1 in 300 could be obtained, would be sufficient to command the agricultural district in their neighbourhood. But there is ample evidence to show that, by the use of the pump, cities lying low in valleys or on the coast could utilise their sewage with a profit. It has been proposed that the experiment should be tried at Brighton, where many elements of success are to be found. The drainage of this growing town is not yet accomplished. This is a great feature, inasmuch as a complete system of double drainage could be carried out—one that would allow a flow of the rainfall to the sea; and of the pipe water, or house refuse, being gathered by itself into some tank, and thence pumped up in its concentrated state to the surrounding estates and farms. We are told that a hundred tons of sewage can be thus lifted 100 feet for a penny. A hundred tons of Brighton sewage undiluted with the rainfall would be worth three or four times the value of the ordinary mixed town drainage; and we are told that the noble proprietors in the neighbourhood of the town would be willing to receive it on their land. Lord Essex, for example, would be too glad of it; and we should say that the ladies, who now bathe in the sewage which empties itself not far from the beach, would be equally glad of its absence—for here it is clearly “matter in the wrong place.” Lord Essex has given it in evidence that he applied 134 tons of sewage to two acres of wheat, and that on each he obtained an increase of produce worth 3l. 1s. 6d. over and above that of other unsewaged fields; and this, remember, with the sewage diluted with the rainfall. What his increase of produce would have been if he had used it in its concentrated state we scarce dare mention; but we feel not the slightest doubt that it would have been more than amply sufficient to pay his lordship and others who used it a sum sufficient to defray the plant and labour of pumping, and to go some way towards lowering the local rates.
At all events, we may feel quite certain that the enormous value of the liquid refuse of our houses is now ascertained beyond the slightest doubt; and there can be as little doubt, we think, that means will speedily be found to transport it from towns where it is a nuisance to fields where it will be a benefit, to the satisfaction of the tax-lightened rate-payer, the officer of health, and the agriculturist; and if not, we may reasonably ask the reason why not, as we are now spending annually many millions of money to bring the inferior fertiliser, guano, many thousands of miles to our fields.
Moreover, we may say that we must have this question answered at once, for it will not admit of delay. Agriculturists have been dreaming that the accumulations of guano are inexhaustible, and that thousands of years will elapse before the stores heaped on the islands off the coast of Peru will be consumed. Mr. Markham, however, who has made a careful estimate of the amount remaining in 1861, considers there was not more than 9,538,735 tons remaining at that date, which, at the present rate of consumption, will only last until the year 1883. Think of this, ye farmers who pin your faith on guano: in twenty years’ time, if you do not manage to utilise the sewage at your own doors, the foreign article will fail, and the predicted exhaustion of the vegetable mould of the country will really begin!
And have our agriculturists for a moment considered of what the home-made sewage manure consists? China manages to keep up the fertility of her soil by simply returning to it the elements that have been taken from it, in the shape of the excreta of the population; but it must be remembered that we import as well as produce, fruits of the earth, and that our imports of food alone amount annually to 75,000,000l.—in other words, our own home-made guano contains the fertilising elements not only of our own soil, but of that of all countries on the earth which pour out their cornucopias into our island to the yearly amount we have stated, and the whole of which is now allowed to run to waste.
We trust, in conclusion, that our “exhausted vegetable mould” will speedily give the lie to the prognostications of the philosophical agricultural chemists who have so frightened our land-owners, and that the picture of England returning to its aboriginal condition of marsh and forest only dwells in their own too vivid imaginations.