Popular Science Monthly/Volume 37/September 1890/Popular Miscellany
The Water-Supply of Memphis.—The city of Memphis, Term., now possesses a complete supply of pure water, which forces itself through artesian wells from a depth of about four hundred feet below the surface. The artesian source was discovered in 1887 by Mr. R. C. Graves, of the Ice Company, who, seeking water suitable for the manufacture of ice, made borings to the depth of three hundred and fifty-four feet. There he struck water, which at once rose to the surface and spouted up in a gushing fountain. This source has since been utilized in numerous private wells of hotels and manufacturing establishments and in the public supply of the city. It lies in a stratum of "water-bearing sand," nearly eight hundred feet thick, which is reached after boring through the one hundred and forty-five feet of hard, impervious clay that forms the "bed-rock" of the region, and furnishes a permanent bottom to the Mississippi River. Above this is a stratum of gravel twenty feet thick, topped by the bluff formation of loess that constitutes the surface of the region and gives character to it. These formations extend a considerable distance to the eastward, and there outcrop one after the other—the water-bearing sand, which is sandwiched between the clay already mentioned and another clay below it, being represented by a tract twenty miles across and of indefinite length, which may be seen in Fayette and other counties along its line down into Mississippi. This region, on which is gathered the water that percolates to the wells of Memphis, is, in its general surface, about three hundred feet above high water of the Mississippi. In May, 1889, there were fifty-seven bored wells in Memphis, five of which only reached the water-bearing sand, while the others went down to depths of from three hundred and fifty to four hundred feet and more. They are included within an area three miles long and one mile wide. The average depth of the thirty-two wells through which the water-supply is furnished is about four hundred feet. They are all connected by a tunnel, five feet in diameter inside, and walled with brick, which has been constructed in the impervious clay seventy-six feet below the upper limit of artesian flow. From the "wet chamber" of this tunnel, in which the water is collected, it is pumped for distribution over the city. The character of the water is shown by the most careful tests to be of the best.
Science in Iowa.—The paper of most general interest in the Proceedings of the Iowa Academy of Sciences for 1887, 1888, and 1889, is the annual address for 1888 of President Herbert Osborn. It reviews what has been accomplished in Iowa in the various fields of science, and gives a forecast of the directions in which work in the future may be conducted with most immediate advantage. The first Iowa Academy of Sciences, which existed from 1875 to 1884, was the means of encouraging investigation in many parts of the State, and secured the publication of a number of valuable papers. The present Academy, of which R. Ellsworth Call is secretary and treasurer, was organized in 1887. Besides this body, the Iowa Assembly of the Agassiz Association, the State Agricultural and Horticultural Societies, Agricultural College and Weather Service are mediums for scientific publication on subjects appertaining to their respective spheres. Anthropological work has been furthered by the Davenport Academy of Sciences. Much has been done by the geological surveys and by individual naturalists from 1819 on. Continued geological studies and the development of the weather service are indicated as the leading lines on which future scientific work may be prosecuted. The proceedings of the three years covered by the volume contain many excellent special papers.
Uses of Slag.—-The slags produced in iron-making vary in composition according to the ore that is used, but are all alike in that their chief constituents are silica, lime, and alumina. From the chemist's point of view they are a kind of impure glass, and they in so far resemble glass that when rapidly cooled they are apt to fly to pieces. The uses to which slag has been longest put are the production of slag-sand by running the molten material into water and the preparation of bricks and mortar from it; and the casting of it into blocks, which are chiefly used in paving. The regular, smooth surface of these blocks is an objection to their use; but this is obviated, and the ideal cleavage surface is obtained by casting them double with a notch around the middle, where they are broken by a sharp blow. Besides being toughened and more dense, the slag, when annealed, has a strong affinity for Portland cement, and unites with it into a concrete of remarkable toughness, which is one of the best pavement materials of its class. The slag, broken by machinery, is largely used in England for road-making; for this purpose, the material should contain about equal proportions of lime and silica and seven or eight per cent of alumina. "Slag-wool," or "silicate cotton," is obtained by turning a jet of steam or an air-jet upon the stream of molten slag as it issues from the furnace. By this the slag is dispersed or broken up into countless small, bead-like particles, each of which, as it flies away, carries behind it a delicate thread of finely drawn or "spun" slag. This substance has several valuable properties. It is extremely light, and absolutely fire-proof; is a non-conductor of heat and sound; and is so porous that it will absorb large quantities of water, and readily retains the same for a considerable time. The last property is important in the use of the substance as a fireproofing material; for, when water is pumped into a burning building, it is held by the slag-wool as by a vast sponge, and will evolve steam sufficient in itself to extinguish the flames, or at least assist powerfully in doing so. It is also an antiseptic; and this property, in conjunction with its great porosity, seems to render it specially applicable for medical purposes. Slag cements are prepared largely at several factories on the continent of Europe. To make them, the slag-sand, dried, is ground fine, mixed with slaked lime, and stamped, and the whole intimately mixed in a "homogenizer" of special construction. The slag cement is lighter than Portland cement, takes longer to set, and is cheaper. It is held in great favor in Germany, though it is not, perhaps, so good in all respects as Portland cement. Another kind of slag—the Thomas, or "basic slag," produced in making steel—is remarkable for its richness in phosphoric acid, and is coming into use as a fertilizing material. The demand for it in Germany already exceeds the whole available production of the country, and it is imported from Great Britain and Austria.
The Formation of a New Island.—An interesting account of the newly emerged volcanic island of the Tonga group is given by Mr. J. J. Lister in the Proceedings of the Royal Geographical Society for March. It has received the name of Falcon Island, and was formed by an eruption in 1885. It was visited during its formation by some natives of the group, who say that the center of action was wholly on one side of the present island; showing that in all probability the wind played an important part in determining its position. The uncovered portion lies approximately northwest of the supposed center. It consists of two parts: a conical mound at its southern end, about one hundred and fifty-three feet high, and a flat extending to the northward, which is from ten to twelve feet above high water. There is a considerable shoal area north of the flat, but at the base of the higher portion the water deepens rapidly. The soil of the island consists of a fine-grained, dark-gray material arranged in strata. The strata are marked by difference in color and the varying thickness of the salts which have crystallized on them. The soil below the surface was found still hot; the temperature at a depth of seven feet being 100° Fahr., while at the surface it was only 74°. With the exception of two young cocoanut-trees, which seemed not very hardy, there was no vegetation but a few bunches of grass; and a moth and small sand-piper constituted the animal population. The island will probably have disappeared in a few years, unless another eruption occurs, as the waves are rapidly wearing the shore line away.
Falcon Island.
The Unselfishness of Doctors.—Dr. Robert G. Eccles, in a lecture on the Evolution of Medical Science, delivered before the Brooklyn Ethical Association, pays a just tribute to the unselfishness of the medical profession. Medicine, he says, "in all ages has attracted into its ranks the most self-sacrificing members of society. As a science, it was born in altruism. To this day it offers the greatest opportunities of any department of life for the practice of the most ennobling graces of character. These constitute a primary cause of its evolution. . . . Medical men stand alone in the earth among all others, striving with their whole might to extinguish their own business. They preach temperance, virtue, and cleanliness, knowing well that, when the people come to follow their advice, their occupation, like Othello's, will be gone. They establish Boards of Health, to arrest the spread of disease, while well aware that such sanitary measures steal money from their purses. How well they succeed is shown by official statistics. . . . Nobody ever fails to send for a physician in typhus fever. Only six persons in a million die of this disease. Many more used to die when no effort toward its suppression was made. Whooping-cough seldom frightens patients, and neighborly old ladies of both sexes give advice. As a consequence, 428 in a million die of this disease. Measles, being a little more serious, needs the doctor oftener, and only 341 in a million die. Scarlet fever is still more alarming, so that medical advice is more in demand, and 222 in a million die of it. Diphtheria frightens still more, thus assuring the doctor's presence oftener, and 168 in a million die. It is thus with every disease: the fewer it kills the more people fear it, because, if they did not fear it, they would play the fool, and give it a chance to kill more people. If bakers, grocers, dry-goods men, carpenters, tailors, and members of all other lines of business, gave as much of their labor in charity as doctors do, poverty would instantly be wiped from the earth."
Dragon-flies and Mosquitoes.—A study of practicable methods of getting rid of the nuisances of flies and mosquitoes has been set on foot by Mr. Robert H. Lamborn, of New York, aided by Mr. Morris K. Jessup; and the first fruits of the effort will shortly appear in the publication of three essays, for which prizes have been awarded. Mr. Lamborn, having been struck with the voracity of dragon-flies, and their activity in destroying mosquitoes and flies, invited attention to the investigation of their life history, and of the possibility of propagating them and applying them directly to the destruction of the noxious insects. The investigations showed that under natural conditions dragon-flies were among the most formidable enemies that the offensive insects had to encounter; but the results as to the practicability of artificial propagation and application were not encouraging. Mrs. Aaron, of Philadelphia, to whom the first prize was awarded, found that, as they do not breed in the same waters as the mosquito, they would have to be produced on an enormous scale and then taken to the mosquitoes; and that the artificial breeding of them is attended with great difficulties. Mr. Archibald C. Weeks, of Brooklyn, made experiments in breeding them artificially, and failed. They can not, moreover, be kept in houses and cities without changing their habits. Mr. William Beutenmuller, of the American Museum of Natural History, finds that dragon-flies are the natural enemy of the mosquito in its various forms and of flies, and that those insects disappear before them, but concedes the difficulty of raising them artificially. These experiments do not dispose of the question of our calling dragonflies into service. Early efforts usually fail of the success that follows patient persistence. Much may be accomplished at once by encouraging the natural multiplication of the Libellulidæ; and future effort may yet develop a practicable way of raising them artificially. Other remedies are suggested which seem efficient and more immediately practicable. Among them are the cultivation of the yeast-fungus, which is fatal to flies, and attacks them frequently; fish-planting; thorough draining of spots where water can stand; and insecticides, one of the most efficient of which is kerosene. One drop of oil applied to a pool having ten square inches of surface cleared it very quickly of all life; and three dollars' worth of crude oil will be sufficient to apply to a mosquito-pond of a hundred acres five times in a season. Spraying petroleum on compost-heaps and other breeding-places is equally effective to prevent the development of flies.
Walking-Sticks and Umbrella-Handles.—The art of making walking-sticks and umbrella-handles has been greatly developed during the last forty years. Formerly, only a very few native woods and some foreign species were used for these purposes. Twenty years ago the first collection illustrating the materials used was presented by a London firm to the museum at Kew. The collection has been completed by a supplementary one from the same house, and in its later form exemplifies many points in the advance of the art. There is now hardly any limit to the material that can be turned to account for the purposes under consideration, and manufacturers keep a keen lookout for new sources of material, and novelties in sticks and fashion. The cultivation of sticks for the market has been taken up as a business at some places in continental Europe, and special attention is often paid to making the roots grow into shapely forms for the handles. A London manufacturing establishment, the floor space of which nearly covers an acre, have extensive storehouses filled with native and foreign sticks, from which stock is drawn, as it is wanted, for the shops. These, as they grow, are often very crooked, and have to be straightened. A heap of sand is provided on the top of a very hot stove, into which the sticks are plunged, and kept till they have become pliable. "The workman then takes the crooked stick while it is still hot and inserts it in a notch cut in a stout board, placed at an angle inclined from him," where he bends and strains it. When it has become perfectly straight it is thrown down to cool, after which it becomes rigid and permanent in its lines. Heat is an important element in this matter, and produces different effects on the several kinds of wood, the degree of heat necessary to straighten one kind of stick being often sufficient to spoil another kind. The same power which makes a crooked stick straight is applied to make a straight one crooked; so we find that the rigid stems of bamboos, partridge canes, and all the various kinds of sticks that are required to be curled or twisted, are by the application of heat made to assume almost any shape or form. Thus we often see ladies' sun-shade handles twisted and even tied into double knots. By far the largest number of sticks used are those known as natural sticks—that is, saplings of trees or climbing plants, when the roots have sufficient character to form handles or knots. These are always more in demand than sticks cut from solid wood. The finished canes are sometimes mounted with precious metals, stones such as onyx, jasper, marbles, even precious stones, ivory, and horns of all kinds.
Microscopic Structure of Stone.—The investigation of the minute structure of minerals and rocks is recommended by Dr. H. Hensoldt as the application most eminently adapted to afford pleasure and satisfaction to the lover of the microscope. It presents an exceeding complexity of forms and a most wonderful display of colors, and offers a field as yet almost untrodden and affording endless opportunities for research. "Especially striking and lovely is the appearance of many of the volcanic or igneous rocks, when reduced to thin sections, and examined under the microscope. The dullish green lava, called pitch-stone, which is found in dikes on the island of Arran, on the west coast of Scotland, exhibits under the microscope whole forests of fern-trees, garlands, leaves, and flowers of marvelous magnificence. A certain granite from Cornwall contains needle-shaped crystals of tourmaline, radiating star-like from a common center. Basalts, obsidians, porphyries, serpentines from various localities, show labyrinths of multicolored crystals resembling rows of pillars, turreted castles, and fairy caves, glowing in all the tints of the rainbow. The sedimentary or stratified rocks, while they can not under the microscope equal their Plutonic rivals in brilliancy of color or gorgeousness of crystalline display, make up for this deficiency by other features of interest, compensating the inquirer with revelations of a different character, but none the less remarkable. Many marbles and limestones are found to be literally composed of foraminifera, the tests of rhizopods, resembling tiny shells of the most delicate and beautiful forms. . . . Thin sections of almost any piece of flint exhibit under the microscope quite a little world of curious organic remains, such as sponge spicules, xanthidia, small fragments of coral, and the foraminifera already mentioned, furnishing very strong evidence that the flints are silicified fossil sponges. . . . This branch of study, though barely thirty years old, has already contributed such a vast deal of new information to natural science that it has, in more than one respect, revolutionized our old-fashioned conceptions of geological research."
Asphalt in Building Construction.—Some interesting examples of recent new uses of this substance are given in a paper with the above title by Mr. T. H. Boorman, published in Architecture and Building. The writer says: "From the cellar to the roof, asphalt has been used where the requirements have been water and fire proof floors. Its principal merits are its utter imperviousness to water or damp, and its elasticity, whereby cracking, especially from the influence of frost, is prevented. Also from a sanitary point of view the advantages of asphalt are incontestable, for it possesses great antiseptic properties, and, owing to its having no joints, it is impossible for particles of animal or vegetable matter to lodge in crevices and putrefy. It greatly promotes cleanliness, as it can be easily washed, and for this reason is invaluable in hospitals, breweries, stables, etc. Asphalt first appears in your specifications as under the item of 'damp course.' It is advisable to lay throughout the walls on the grade of the cellar-floor half an inch of asphalt, with a lap of about two inches on the inside, so allowing a connection with the asphalt finish of the cellar-floor and hermetically sealing the house from damp, noxious gases, and vermin. In residences you will probably consider you have done your duty by asphalt if you have thus specified for your damp course and cellar-floor; in the latter, by the way, three fourths of an inch of asphalt on three inches of hydraulic cement concrete will serve the desired purpose of a durable damp-proof floor. The yards of city residences are now frequently laid with asphalt, the material being peculiarly adapted to the roller-skates and tricycles of the younger members of a family. From a building, then, in which only one floor, the cellar, is required to be of asphalt, let us consider where every floor and the roof can be of this material; in printing-houses, lithographing establishments, breweries, sugar-refineries, and slaughter-houses, you will often find this material used throughout. This year, however, sees a novelty in construction with asphalt. Theophilus P. Chandler, Jr., architect, of Philadelphia, is using rock asphalt on every floor of a large apartment-house; the carpets will lie on the asphalt, being fastened down to narrow strips of wood set against the partitions when the asphalt is laid. Now, I fancy I hear you say, ' Well, asphalt is not pleasant in appearance.' Why, gentlemen, the mayor's private office in the great City Buildings of Philadelphia, the greatest municipal edifice in the country, is laid with asphalt with a border of colored tiles."
Some People of New Guinea.—Of the natives of the neighborhood of the Owen Stanley Range, New Guinea, Sir William MacGregor says that their features are decidedly good, and their faces indicate more character and strength than those of the average coast men. The cheek-bones in some are rather broad and prominent. The nose is generally of the Semitic type. They possess all the volubility of the Papuan race, and are less shy than tribes that have seen more of white men, but are apparently superstitious and easily frightened. "They informed us that they used both the bow and the spear, but we never saw one of them with a weapon, and I could not induce them to bring any to camp; not, as it appeared, as if they mistrusted us, but seemingly doubting whether it would not be misunderstood should any of them with arms in their hands meet any of our party away from camp." They always left the camp before nightfall. They would exchange food for salt, beads, and cutlery, but did not care much for tobacco, growing a good quality of their own. They also cultivate peas, beans, yams, sweet potatoes, and several varieties of bananas, and have abundant food.
Origin of the American Indian.—Prof. F. W. Putnam, in an address before the Archæological Association of the University of Pennsylvania, said, in reference to the origin of our Indians, that two well-defined groups of races are found in America. They have entirely different-shaped skulls. One group starts in Mexico and reaches to Peru. They are a short-headed people. They extended across from Mexico along the Gulf coast, up the Mississippi Valley and along the southern portion of the Atlantic coast, not crossing the Alleghanies and not being found north of the Great Lakes. They were the people that built the mounds and founded the civilization of Mexico and Peru. Another race, a long-headed people, inhabited the northern part of the country, and were the authors, among other articles, of certain objects found in Wisconsin. These two races have,met and mingled, and the result is the American Indian.
Results of M. Pasteur's Anti-rabic Treatment.—M. L. Perdrix's report of the antirabic vaccinations at the Pasteur Institute since 1886 divides the cases treated into three classes: those of persons bitten by dogs ascertained experimentally to be mad; of persons bitten by dogs decided by veterinary examination to be mad; and of persons bitten by dogs supposed to be rabid. The proportion of deaths after treatment is shown by the tables to be very small; for a total of 7,893 cases of all the classes, it was 0·67 per cent; but the proportion has decreased from year to year; it having been 0-94 per cent in 1886, 0·73 in 1887, 0·55 in 1888, and 0·33 in 1889. The decrease is attributed to a better appreciation of the gravity of the cases and a more judicious proportioning of the measure of treatment to that feature. The gravity of the case appears to vary somewhat according to the part of the body that is bitten. The most dangerous bites were in the head, with which the mortality was 2·36 per cent; next were the hands, 0·69 per cent; and last the body and limbs, 0·27 per cent. The inferior gravity of the last class of bites may, perhaps, be attributed to the action of the clothing in wiping the animal's teeth.
The Unexplored Regions of Canada.—It is commonly supposed that all parts of Canada have been explored and are known. Mr. G. M. Dawson thinks that this opinion is not correct, and that the clearness of the maps, on which it is chiefly founded, is due to their makers having assumed for regions of considerable extent what has not been verified. Probably but little of the regions which are really unknown is agriculturally or climatically attractive; but they may contain mineral wealth, and some of them may in time have value for cultivation. In marking out the districts which he regards as unexplored, the author takes no notice of comparatively small tracts of country lying between explored regions, or of any having an area of less than 7,500 square miles; and he also omits the arctic islands lying to the north of the continent. With these limitations he enumerates and defines sixteen distinct regions in the Dominion concerning which definite and satisfactory information is wanting, varying in area from 7,500 square miles to 289,000 square miles. In all, it may be stated that "while the entire area of the Dominion is computed at 3,470,257 square miles, about 954,000 square miles of the continent alone, exclusive of the inhospitable detached arctic portions, is for all practical purposes entirely unknown. In this estimate the area of the unexplored country is reduced to a minimum by the mode of definition employed. Probably we should be much nearer the mark in assuming it as about one million square miles, or between one third and one fourth of the whole. Till this great aggregate of unknown territory shall have been subjected to examination, or at least till it has been broken up and traversed in many directions by exploratory and survey lines, we must all feel that it stands as a reproach to our want of enterprise and of a justifiable curiosity. In order, however, to properly ascertain and make known the natural resources of the great tracts lying beyond the borders of civilization, such explorations and surveys as are undertaken must be of a truly scientific character."
Crystallization seen in the Act.—The process of crystallization as observed under the microscope is described by Dr. H. Hensoldt in a paper on crystallogenesis. The commencement of the operation is always signaled by the sudden appearance, in the previously clear and colorless field, of innumerable dark points, which, in an incredibly short time, augment in volume, till a diameter of perhaps 1500 of a millimetre is reached. It is then observed that the particles are spherical in outline, and that their darkness is only an optical illusion, caused by a broad diffraction-ring, for in reality they are quite transparent. They are evenly distributed over the field, and their "growth"—a kind of spontaneous swelling, which can be plainly followed—is uniform and simultaneous. The particles then appear to become suddenly endowed with polarity; they change their positions, roll about like billiard-balls in every direction, yet always in straight lines. For a moment all seems confusion, but behold! some invisible "floor-master" is asserting his authority, and in another instant we have the first manifestation of a symmetry destined to culminate in that perfect crystalline regularity which has excited the wonder of all ages. The globules, originally scattered all over the field, are now arranged in lines or rows, like so many strings of beads. Some of these rows consist of only three or four globules, in others we can count ten, fifteen, twenty, or more; and it would seem as if each spherical body was surrounded by a delicate film or pellicle, which prevents the dissipation of the internal molecular forces. A series of rapid changes is now inaugurated, which can be followed only with the greatest difficulty. The globules in each line, by a sudden and simultaneous movement, unite and form solid rods, and there are grounds for believing that this solidification is due to the rupturing of the mysterious pellicle referred to. Within a quarter of a second after the formation of the rods (which are of uniform thickness, however much they may vary in length), we observe a general commotion among them. Each now appears to act as a separate bar-magnet, and while some unite at right angles, others range themselves in close contact side by side, and form a symmetrical wall. Layer is piled on layer; each little rod falls mechanically into its proper place; and before we have time to realize the strangeness of the spectacle, the field is studded with little cubes of exquisite brilliancy. What we have seen here in an evaporating drop of chloride of sodium may be observed in any other saline substance which we allow to crystallize under the microscope, with the sole difference that the diameter of the globules and the form of the ultimate crystals vary according to the nature of the substances employed.
The Genuineness of the "Nampa Image."—The Boston Society of Natural History had a discussion a few months ago respecting the "Nampa image," or the little human figure of clay that was found in boring a well at Nampa, Idaho, in August, 1889. Prof. Wright produced letters and statements substantiating the genuineness of the discovery and certifying to the eye-witnesses of the fact as men of unimpeachable intelligence and integrity. A report by Mr. Albert Allen Wright, on his examination of the image as to the material of which it is made and its appearance, stated conclusions favorable to its antiquity. Prof. G. F. Wright regarded the direct evidence as of as high order as could well be obtained. "There was no sensational publication in the papers, nor has there been any suggestion of mercenary motives. There were no archaeologists or scientific men on the ground to be humbugged. Apparently the image would have disappeared and dropped out of notice but for the fortunate chance which brought it to the attention of Mr. Adams, when his own mind was interested in that class of subjects. The evidence is most direct as to the impossibility of the image's having fallen into the well from the surface, or of its having been put in by design." Much weight is also attached to Prof. F. F. Jewett's opinion as to the character of the iron oxide on the image. "It seems in the highest degree improbable," Prof. Wright adds, "that any one should have manufactured such an object on the spot, and been so successful in meeting all the conditions present. I am, therefore, prepared to accept without further question the genuineness of the image, and shall look for further confirmation as time elapses." Prof. Putnam spoke of natural evidences which the image afforded of its age. Prof. H. W. Haynes said that he regarded the image as a most important evidence of the antiquity of man in America.