Popular Science Monthly/Volume 33/August 1888/Popular Miscellany
The Dynagraph.—From a description of this instrument, which its inventor, Mr. P. H. Dudley, read before the New York Academy of Sciences, we select a few notes. The first dynagraph was made in 1874, and used paper eleven inches wide for its records. A later instrument uses paper of twenty or thirty inches width as desired. The recording apparatus occupies a floor space of about thirty-four by forty inches, in a car specially constructed for its use, and is thirty-seven inches high. It is placed over a special six-wheel truck, which carries many distinct sets of apparatus to furnish required indications, the results being electrically recorded by the battery of electro-magnetic pens on the recording apparatus. As the car moves, the paper is fed through the instrument, the rate when inspecting track being one inch of paper for each fifty feet of track. The apparatus may, if desired, take the dynamo-metrical curve, and inspect the track at the same time. From this curve, the number of foot-pounds of work expended in moving the train any selected distance is calculated. All movements of the cut-off, up or down, or of the throttle-valve, in or out, are shown by the curve. Aside from all other conditions, each engineer, especially on a freight-train, gives the curve a personal equation, a good one, if he is a first-class runner, thoroughly acquainted with the line, so he is able to work his locomotive to the best advantage, saving in fuel and time. Such engineers can draw more cars, with a given locomotive, than those who are not so well versed. One practical result of the use of the dynagraph was the discovery which has been verified in practice, that for freight-trains, on the Lake Shore and Michigan Southern Railroad, the locomotive gave a much more economical development of power running eighteen to twenty miles an hour, than when running ten to twelve miles. Further, the saving in running time of a train from Chicago to Buffalo was twenty-four hours, giving the road a much greater capacity with the same equipment. The track inspection includes the measurement of surface undulations and side deflections in the rails, the measurement of gradients, and of the curvature and alignment of the line. Lines are also traced showing the distance passed over, the time in seconds, side oscillations of car, the consumption of each cubic foot of water, and each twenty-five or fifty pounds of fuel, the velocity of wind, revolutions of drivers, intervals of firing, and duration of black smoke. Any special piece of electrical recording apparatus can be put in circuit with a pen, and its indications recorded. From the character of the delineations it is at once seen whether the rails are rough and bent, joints low, worn out, or loose on the ties, and whether any permanent improvement which can be made by labor or new material is required-As the car runs over the track "low-point markers" eject paint under the heads of the rails where deflections occur, thus showing to trackmen where their labor is needed. Diagrams of track inspection have demonstrated that with sixty-five or sixty-seven pound rails the deflections were more than was generally supposed, and have led to the introduction of seventy-two and eighty pound rails.
Systematic Reading for Teachers.—Dr. Jerome Allen, of New York, gave, at the meeting of school superintendents held in Washington last year, a summary of the principles on which the teacher's systematic reading should be conducted. In the matter of primary knowledge as a teacher, he ought to read that which will most directly help him in the work of instruction. His pupils are human beings; he must know what they are, morally, mentally, and physically. He is especially set to train the mind; it follows, then, that he must study mind growth and mind-science. How to train the mind into a symmetrical maturity is the most important knowledge a teacher can gain. All text-book knowledge is secondary in comparison with this. If a teacher knows all science, literature, and art, and does not know the mind and its growth, he is not prepared to teach. His work is empirical. The reading for secondary knowledge comprises methods of instruction, organization, school government, school systems, school laws, and the history of education.
The Three Grades of Hand-Work.—In a paper on "Sense and Hand-Training in Public Schools," Prof. Joseph Le Conte affirms that as drawing, if introduced, should be not for making artists, but for training the brain through eye and hand, so hand-work should be not for making carpenters or blacksmiths, but to train the brain by co-operation of hand and eye. If in biology the training is mainly of the brain through the senses, in hand-work the training is mainly of the brain through the hand. If one is mainly observing and thinking, the other is mainly thinking and doing. It is impossible to doubt the importance of hand-training from this point of view. All admit the absolute necessity of the use of the hand in the brain-culture of the child. All now admit also that the best scientific culture in the university requires the use of instruments of research—the microscope, telescope, the balance, the measures of force of many kinds. But in the whole wide space between, viz., in the school and the college, this great agent of culture is wholly left out. Now, I am quite sure that for every grade of culture, whether of the individual or of the race, there is a corresponding grade of hand-work necessary for the best brain-culture. In the child of preschool age and in the savage and in palæolithic man, it is the simple use of the hand, or assisted by rude implements. In the school boy or girl, as also in the next higher grade of races, it is by the use of those finer instruments which we call tools. In the university, as in the most civilized races, it is by the use of scientific instruments and machines. The three grades of hand-work, then, are the use of implements, tools, and instruments. That especially adapted to the schools is the use of tools. But not only is hand-training in the schools an immediate and very urgent want, but by the necessary differentiation of human pursuits and the increasing divergence of school from actual life, is becoming more so every year.
Perforated Stones from California.—These objects are found abundantly in Southern California, varying in weight from an ounce, or even less, to several pounds. In shape they are most frequently circular, or nearly so, but occasionally they are irregularly oblong, and some are more or less globular, while others tend to the pear-shape. Mr. H. W. Henshaw states that by the surviving Indians of Santa Barbara and Ventura Counties the stones were formerly put to three uses: first, as weights to digging-sticks; second, as gaming implements; and third, as dies for fashioning tubes, pipes, and similar cylindrical objects. A Santa Barbara Indian, to whom a specimen was shown, a man sixty or more years of age, unhesitatingly affirmed, the moment he saw it, that it was a digging stick weight. This implement, he said, was formerly in use among the women in his tribe. The stick must be strong and very hard; the wood usually employed grew only in the mountains. The especial function of the digging-stick was to dig a kind of onion-like root. When in use, the weight was slipped over the handle till it rested at about the middle of the stick, like a collar. An old woman living in a village of the San Buenaventura Indians, thirty miles distant, corroborated the above statement as to the use of the stones. When one was put into her hands it at once excited her surprise and interest. In reply to the question, "What do you know of its use?" she instantly seized a small stick from the fireplace and slipped the ring down to its middle, holding it there with the left hand, and began to dig industriously into the dirt floor. From an intelligent half-breed of the same village, Mr. Henshaw learned that many of the stone disks were used in a game which was played as follows: A piece of level ground was selected for a court, and was made very smooth and hard. At one corner of the court was stationed a man whoso business it was to cast the disks. The player, with a lance six or seven feet long in his hand, stood on one side of the court. Running a little distance, the bowler rolled a disk swiftly across the court, when the lance-thrower darted forward and cast his lance, the object being to transfix the disk as it rolled past. A successful throw counted one point, ten being the game. Dr. W. J. Hoffman was informed that at Santa Barbara the bow and arrow were in use in this game in place of the lance. The San Buenaventura half-breed stated that some of the perforated disks of hard stone were made for the express purpose of fashioning pipes. The end of the stone to be fashioned was inserted into the hole of a perforated stone and turned by the hand till reduced to the proper shape. The perforated stone hence served as a kind of die. Mr. Henshaw has found no evidence to show that these stones were used as net-sinkers, spindle-whorls, or club-heads.
A Fatal "One Glass."—A new book, called "Manners Makyth Man," gives a story told by a bishop of how he persuaded a man recovering from delirium tremens to become a teetotaler. "Years went by, and not a drop of intoxicating liquor entered his mouth. Six, seven, eight years passed, and his resolution remained unbroken. On the anniversary of the eighth sober year his friends, thinking the reformation complete, resolved to give a dinner in his honor. A family circle, rendered happy by the temperance of its head, received the congratulations of intimate friends. But it was a feast of deadly wine. Healths were proposed, and he who was being honored was told that to drink his own health in one glass could certainly do him no harm after totally abstaining for eight years. He drank the glass, and two years afterward I was called in to visit a poor drunkard who was on his death-bed by reason of that one 'friendly glass.'"
Technical Education.—In a paper on "Technical Education," G. S. Ramsay maintains that British workmen are not deficient in technical skill in any mechanical department, but, as a rule, distance those of most other nations. British work is inferior to foreign in two classes of departments: in those connected with processes requiring a scientific knowledge of chemistry of the highest kind, and in those in which success depends essentially upon taste, and upon the faculty of design. An instance under the former category is given in the manufacture of coal-tar dyes, which has been carried off from "under the very noses" of the British by the superior scientific skill and industrial capacity of another nation. British manufacturers furnish the material; Germans, under the direction of trained chemists, work it up, and sell back to the British the products in the form of beautiful colors and concentrated essences. Thus a works near Basle employs a chemist of comprehensive training and experience, three departmental chemists, and several assistants. Another one, near Frankfort, employs fifty-one scientific chemists. The manufacture of beet-sugar has been developed in Germany into a great trade by being treated as a scientific business, "to be carried on in strict obedience to the commands of scientific experts." In these operations the-technical part of the work is made subordinate to the scientific principles on which it is based. British butter and cheese are being superseded in the markets by American and Canadian products, through the neglect of scientific improvements at home and the introduction of them in the competing countries. "In each of these cases," says Mr. Ramsay, "we find the same state of things. The British producer fails to understand the importance of pure knowledge; be despises and disbelieves a knowledge of principles, and imagines that the only thing he need know is the application of those principles to his own particular work. In his eyes practice is everything, knowledge for its own sake, knowledge of principle, is nothing; as if there could be any value at all in practices unless he knows the reasons on which they rest. Our producers are like students who cram for an examination by getting up 'tips,' instead of getting up sound knowledge of the subject. The present cry for technical education is itself, to a large extent, only a new example, in an exaggerated form, of the same vicious idea. So far as it leads people to suppose that success in production or in life is to be gained from a knowledge of technique—of methods, of processes, of manipulation—instead of impressing upon them that all these are wholly unimportant and useless in with a real education in the subject concerned, and a knowledge of the principles on which the technique is founded, its effect will be wholly bad. The idea that there are short practical cuts to just so much knowledge, and no more, as we need for the particular job in hand, is one which, if adopted, would demoralize our education to its root, as in diametrical opposition to the whole tenor of the evidence which has been collected in Germany and other countries."
A Jadeite Adze from Mexico.—Mr. George F. Kunz exhibited at the American Association a jadeite adze found at Oaxaca, Mexico, about twenty years ago, which was remarkable for its extraordinary size, and for the peculiar character and excellence of the working exhibited in so hard a material. It is 1013 inches long, 6 inches wide, 45 inches thick, weighs 229·3 oz. troy, and is light grayish green, with streams of an almost emerald green on the back. In style of ornamentation it closely resembled a gigantic adze of granite which is mentioned by A. Chavero in his "Mexico al Través de los Siglos," and it has almost an exact counterpart in the aventurine quartz adze now forming a part of the Christy collection at the British Museum. It, however, differs from these objects in having no ornamentation on the forehead, and in having in addition three dull markings on each ear, one under each eye, and one near each hand, which could serve no other purpose than to hold thin flakes or films of gold, of which, however, no trace can now be seen. The adze is, from all appearance, the result of the shaping of a bowlder, for it presents evidences of weathered surfaces. The lapidary's work on this piece is perhaps equal to any that has ever been found, and the polish has not been surpassed. It is an interesting fact that, notwithstanding this adze is one of the finest objects which its Mexican owners possessed, they desired to "extend" the material; and for that purpose made three attempts to remove pieces from the object. Enough has been cut from the back of the adze to equal, perhaps, one eighth of the entire weight. The appearance of the cuts gives support to the supposition that the cutting was done with a string and some abrasive. The author had previously described in the "American Journal of Science" for July, 1882, a sapphire pebble found in a brook at Oaxaca. If the people were acquainted with this mineral, we can more readily understand how they were able to work so hard a substance as jadeite. So far as the author was able to understand, no similar object of such magnitude and equal archæological interest exists. The Humboldt celt, the Leyden plate, the Vienna adze, and the adze in the Ethnological Museum at Dresden, can hardly compare with it.
The Name of America.—Evidence is accumulating that the name of America is indigenous to our continent, and not borrowed from the name of an early navigator, as the world till now has supposed. M. Jules Marcou has found it in the name of a range of mountains in Central America—the Amerique range—and also in that of a tribe of Indians living upon it—the Ameriques. A more careful and thorough study of the subject has been made by Mr."Thomas de St. Bris," whose pamphlet. Discovery of the Origin of the Name of America, can be obtained by addressing P. O. Box No. 1853, New York city, or from the American News Company. It appears from his investigations—the sources of which he names and are nearly all to be found in the Astor Library and the American Geographical Society's maps and atlases—that the root of the name America was widely scattered over Central and South America at the time of the conquest. It appears in the kingdom of Amarca, Caxamarca (or Peru), in Amaraca on the west coast of Central America, and in the forms Cundin Amarca (Bogota), Tamaraqua, Amaracapand, Caxamaraca, Andamaraca, Cataraarca, and many others, applied to various places, which are indicated on the maps with which the pamphlet is illustrated. As the authorities for these statements are fully described and easily accessible, students have ample opportunity for verifying or refuting Mr. St. Bris's theory. In further confirmation of these views, M. Marcou asserts that Vespucci's name was Alberico, or Albert, and never Amerigo, till he had returned from his American voyage and had adopted or been given a name commemerating his travels.
Changes on the Zambesi.—According to the observations of British Consul O'Neill, of Mozambique, the Zambesi River is working out important changes in its course near Maruru. About six miles south of the position of his camp was a long, swampy lake, which once formed the course of the river. Some obstruction in the bed of the stream deflected its course to the northward, and the old bed was left as a still lake or backwater, which is now filled only from its eastern extremity. This alteration has made great havoc on the northern bank of the river, where the rush of waters has torn and continues to tear away the country which separates the Zambesi from the Mutu and Barabango and other swampy depressions that drain into the Quaqua or Quillimane River. A little more than two years ago the African Lakes Company purchased a house at Maruru which stood eight hundred or one thousand yards from the river-bank. When Consul O'Neill visited the place in April, 1884, the river was running swiftly past the front walls of the house, the foundations of which it had already sapped. The front rooms had fallen in, and only the back part of the house was habitable. These changes are destined, of course, to make considerable changes in the delta of the Zambesi, and in the depth of channels now navigable. No improvement has taken place in the method of navigating the Zambesi, and no attempt has been made to improve it since it was first ridden upon more than three hundred years ago. Boats which will just do on a still-water canal, have to be forced against a powerful current, "at times with oars, at times with paddles, at times pulled along shore with the crew harnessed to a rope, not unfrequently swept into mid-stream by the strength of the current, and turned like a top."
The American System of Water-Purification.—As described by Prof. Albert R. Leeds, this comprises three distinct features: artificial aeration under pressure; precipitation of dirt, sewage, hardening constituents, and coloring matters by harmless precipitants; and mechanical filtration through filters capable of rapid reversal of current, and cleansing by mechanical means. Artificial aeration was first applied to a city water-supply, by Prof. Leeds, in Philadelphia, in consequence of an extremely offensive taste and odor developed in the Schuylkill water, in January and February, 1883.
This treatment has produced a marked improvement, as shown by analysis, in the quality of the water of a number of cities which have employed it, has corrected the offensive taste and odor, and has stopped the growth of green scum in reservoirs.
The reasons for advocating the use of air under pressure are, first, because the disagreeable taste and odor in unportable water are frequently due to gaseous and volatile impurities, which can be largely swept out of the water by the use of an excess of air acting mechanically as a deodorizer and disinfectant, thereby exerting a sweetening action in the manner of a water-scrubber; and, second, because chemical and biological analysis show that where sewage is being broken up it is in presence of large numbers of bacteria, which grow and multiply upon this material. Through the vital processes of these bacteria oxygen is rapidly absorbed and carried to the sewage, which is thereby broken up into nitrites, nitrates, carbon dioxide, and other partly or wholly oxidized compounds. After the work of these microbes is completed, they either perish or remain as resting spores, and then they should be removed, together with the products of their labors, by filtration. Assisted precipitation is employed to remove suspended matters in very fine particles, the dissolved salts which make water hard, and coloring matters, especially the peaty substances that produce a dark-yellow stain. Sulphate of aluminum, or the ammonium aluminum sulphate, which is common alum, has been found to be the best precipitant for the suspended substances, forming with them an insoluble coagulum. One grain of alum to the gallon is ordinarily sufficient, and this has no deleterious effect on the water. The insoluble clot which it forms carries down with it the products of putrescent decomposition which are present, and the microbes, or so-called disease-germs. For softening hard water, the precipitant used is lime, the lime carbonate thrown down being removed by filtration. The only material yet found to be available for filtration on a large scale is fine sand. In order to avoid the expense of the system of sand filtration, which has long been employed in England, a mechanical contrivance, called the National Filter, has been devised in this country. The filter consists of a closed tank, two thirds full of sand. The water enters at the top of the tank, filters downward, and escapes by a perforated pipe at the bottom. To clean the filter, a reverse current is sent in by a perforated pipe lying about a foot below the surface of the sand, most of the dirt being deposited in the upper six inches, and the water, after taking up the impurities, escapes by an outlet at the top. A reverse current is then sent through the sand by the perforated pipe at the bottom. Every portion of the bed is floated loose, and by the attrition of the grains of sand upon one another the impurities are scrubbed off; they are then floated to the top, and carried away. When the cleansing is complete, the reverse current is shut off, and the sand settles down into a fresh, uniform filter-bed.
The English Glacial Moraine.—Prof. H. Carvill Lewis's studies of the glacial terminal moraine of England were based upon the principle that every glacier, at the time of its greatest extension, is bounded and limited by a terminal moraine. The great ice-sheet which once covered northern England was found to be composed of a number of glaciers, each of which was bounded by its own lateral and terminal moraines. These glaciers were studied in detail, as the North Sea glacier, the Wensleydale glacier, the Stainmoor glacier, the Aise glacier, the Irish Sea glacier, the separate Welsh glaciers, each of which was found to be distinguished by characteristic bowlders, and to be defined by a well-marked moraine. The great terminal moraine of the united glaciers of England is a very sinuous line, five hundred and fifty miles in length, extending from the mouth of the Humber to the farthest extremity of Carnarvonshire; and, except where it separates the Welsh glaciers from the North Sea glacier, it everywhere marks the extreme limit of glaciation in England.
The "High-Altitude" Cure for Consumption.—In contemplating the resort to a high altitude for treatment of consumption, which is now becoming common, it is well to consider whether the constitution of the patient is adapted to the conditions that he will meet there. From the fact that the atmospheric rarefaction at elevated positions throws a greatly increased strain upon the circulatory apparatus, we have a right to regard valvular disease of the heart or feeble circulatory power as a strong contraindication against trying the high-altitude treatment. For a similar reason that treatment is inapplicable to persons of advanced age, in whom the arteries are likely to have undergone more or less of senile degeneration. As the rarefaction of the air increases the number and depth of the respirations and promotes the elimination of carbonic acid from the lungs, it is not adapted to cases in which the lung-tissue has been much destroyed. Although superficial effusions of blood are sometimes suffered at great heights, bleeding at the lungs has not been observed there, and the danger of it is not believed to be increased. The prevalence of cold at high altitudes is a fact to be considered by persons whose sufferings are increased by low temperatures. The combination of cold, dryness, and rarefaction constitutes a climate of a highly stimulating character. It is consequently exciting, and unfavorable to nervous persons, while it may be beneficial to the phlegmatic. The cases that do best at high altitudes are those of simple phthisis, in patients who are free from cardiac, renal, or rheumatic complications, and who exhibit a torpid reaction to the disease.
Increasing the Tractive Power of Locomotives—Patents were granted in March to Elias E. Rics and Albert H. Henderson for methods and apparatus for increasing the tractive power of locomotives and other self-propelled rail vehicles. This is accomplished by increasing, by means of electricity, the frictional adhesion between the driving wheels and the rails. The apparatus consists of a dynamo-electric machine on the locomotive, from which a current of electricity passes through a converter, and thence through the driving-wheels in succession and that portion of the rails between them. Further, the current, which is of great volume and small motive force, is said to cause enough heat at the point of contact to vaporize at once any moisture on the rails, thus overcoming the slipperiness caused by snow and sleet. The inventors claim that, by their plan, the tractive power can be nearly doubled without increasing the weight of the locomotive, that a 40-per-cent grade can be more easily surmounted than a 7-percent one under the old system, that trains can be stopped and started much more quickly than at present, and that the friction obtained is cheaper than sanding, without its consequent wear.
An Exhibition of Insects.—An exhibition of useful and injurious insects was held in Paris a short time ago, at which five hundred entries of objects were made. Great pains were taken to awaken interest in it. Prizes were offered to school-children for the best compositions on their visits to it. Conferences were held in the rooms on questions relating to the study of insects. Medals were offered to rural teachers who sent collections gathered by themselves or their pupils. Booksellers offered books to those who sent the best collections and the best papers on entomology. Anatomical preparations were shown by Dr. Ozouf representing the organization of the silk-worm in its several states and of May-bugs; silks from Tonkin and Senegal; oak silk-worms raised in the open air which furnish a silk identical with the Chinese pongee; living ant-hills collected by M. Morel, a journeyman painter; ant-lions which had excavated their dens in the sand as if they had been in the woods; batrachians, lizards, adders, aquatic insects, wasps building and repairing their nests, bee-hives with windows through which the bees could be seen at their work; wasps' nests from Senegal, remarkable for their excessive hardness; gall-nuts of various kinds, and collections from several countries, with illustrations of various features of insect life and economy.
Construction of Mythologies.—Closely connected as mythology and folk-lore are shown to have been, says Mr. J. A. Farrer, it is difficult or impossible to say in any given case whether the superstition is derived from the myth or the myth from the superstition. The usual method of interpretation deduces superstition from mythology, making the latter the primary starting-point. But it is often quite as likely that the custom was there first, and that the myth made use of already existing customs; for instance, that the horse figured conspicuously in legend because it had long been an object of worship or superstition, is as likely as that it became an object of worship or superstition because it figured so conspicuously in legend. The horse is thickly set in folk-lore. In parts of Germany a horse's head may still be seen over the doors of cattle-stalls or about the houses—a custom which survives among ourselves in the luck attaching to a horse's hoof. This, perhaps, dates from the custom of our ancestors, mentioned by Tacitus, of keeping white horses in sacred groves at the public expense and idle, and forecasting the future from their neighings. A horse's neighing always presaged victory to a warrior, as his silence presaged defeat, and the French anticipated disaster at Agincourt from the fact of their horses not neighing on the eve of the battle. A horse's hoof under a child's pillow is supposed to be a preventive from convulsions, a horse's teeth are a safeguard against toothache, and houses at which they shy are threatened with calamity. There is no reason to look for any more abstruse explanation for the part which animals, birds, fishes, and insects play in the tales of the gods and heroes, than the fact that they were already accredited in popular superstition with the powers which they display in the stories. Seeing how many of the European peasantry still construct mythologies in an old-fashioned way, and cling to the old views in spite of science, we should have less difficulty in believing that the Greeks and Hindoos originally proceeded in the same fashion, without that constant reference to the struggle between light and darkness which some writers ascribe to them.