Popular Science Monthly/Volume 52/December 1897/Fragments of Science
Unselfish Science.—One of the happiest features of the opening session of the American Association at Detroit was the welcoming address of ex-Senator Thomas W. Palmer. Amid the general scramble for money power which characterizes the present age, he said, "it is gratifying to know that there is an increasing number of men and women who, ignoring the common objects of ambition, have devoted themselves to and are diligent in the unselfish pursuit of truth." These men and women find in the phenomena of Nature history related with accuracy and predictions certain to be verified. "Formerly it was considered that there was a conflict between science and religion. Let us hope that that day has long been passed, and that the more enlightened public recognizes that religion has to do with the spiritual nature of man and science with physical phenomena." The speaker had been seeking a definition of science, and conceived as the most satisfactory one to his mind "the classification of phenomena to the end that principles may be established and declared from which may be deduced rules of action that shall be applicable to particular cases. When did science first originate? Back of the dawn of history, when primeval man, emerging from the shelter of the cave before he had even built him a hut, commenced to apply the force of Nature to his use. . . . How did science originate? By extended observations, experience, and comparison. The first savage who played in the water with his reed as a baby does with a straw, blowing and sucking it, gave the first illustration of hydraulics. The little savage playing in the woods at the ancient game of seesaw would find that the heaviest boy would have to sit nearest the center, and this would give the first suggestion of the lever."
The Beginning of Photography.—A bust of Daguerre, the inventor of the pioneer of all photographic processes, was dedicated at Bry-sur-Marne, where he died, June 27th, in the presence of representatives of the French Government. The idea of fixing by some chemical process the pictures which were formed on the screen of the camera obscura had been entertained, and many persons had tried to discover the art before Daguerre was born; but it was left for him, with the co-operation of Niepce de Saint-Victor, to accomplish the object. Daguerre was not a chemist or physicist, but a decorative painter, who when business was slack was not above painting theater scenes and panoramas, which had been introduced into France by our Fulton; and he derived much profit from a diorama which he exhibited with Bouton from 1822 to 1830. While thus occupied he met Niepce, a man of scientific knowledge but none of business. He told Daguerre of some experiments he had made in heliography, and a proposal of partnership followed in 1826. Niepce, however, never reached a practical result, but died in 1833, leaving a son who continued his researches. Daguerre in the meantime had acquired some ideas in chemistry and knew all Niepce's secrets, but was not able to use them alone. He formed another alliance with the son. In 1839 this younger Niepce called Daguerre into his laboratory and showed him a complete image fixed upon a silvered plate—the first daguerreotype. From this the photographic art has been developed by a succession of brilliant discoveries. No exact mathematical award of the merit of the invention can be made between the partners, but they must receive each an undivided share alike; but Daguerre has certainly reaped the wider fame. The discovery created a great sensation. In order that it might be placed immediately at the service of the public, the French Chambers, on motion of Arago, awarded pensions of six thousand francs to Daguerre and four thousand francs to Niepce as the price for which it should be made free.
The Career of a Floating Bog.—Floating bogs are very prominent features in some of the lakes of Minnesota. They have not, however, been found very abundant by Mr. Conway MacMillan in the Lake of the Woods. As developed, Mr. MacMillan says, the floating bog comes to have some characters peculiarly its own, due to its moving about in the water and its removal from any particular point of attachment. A redistribution of its component plants takes place, and the peripheral areas are specialized from the central. A group of plants may be distinguished at the water's edge, able to bear the lapping of the waves and enjoying the higher illumination. At the center of the island shrubs, or even small trees, may become established. Drifting about from one shore to another, touching at different points, and frequently exposed to strong winds while in transit, the bog becomes a resting place for numerous varieties of light seeds. It is, further, sometimes colonized by the plants of the region near which it may be situated. Thus the number of species of plants established upon it tends to rise; and floating bogs of long standing are scenes of very sharp struggle for existence among a considerable number of alien plants. The undulating movement communicated to the bog when exposed to wave action loosens somewhat its tangled network of roots and decayed organic substances, so that the nature of its soil is modified. The presence of the lake water underneath every part of the formation keeps it cool and moist beyond what is possible in an attached morass. These various conditions are sufficient to give the floating bog a population distinctively its own. It often happens that after floating for a season or two, or even for a number of years, a bog is carried into some angle or cove from which it does not readily escape, and may become anchored there. It is then subjected to the influences of the new environment, and is modified accordingly.
Limits of the Power of Hearing.—Lord Rayleigh began a lecture at the Royal Institution on The Limits of Audition by observing that one of the latest determinations of the frequency of vibrations to which the ear is sensitive gave the lower limit as twenty-four complete vibrations a second, and the upper as about twenty thousand a second. These limits are, however, very ill-determined, because the matter depends largely on the vigor of the vibration and the individual ear. Old people do not hear high notes which are audible to young persons, and the speaker had reason to believe that babies hear notes which persons twenty or thirty years of age can not detect. Experiments on the extent of vibration necessary to audition were described, which appeared to show that a vibration having an amplitude expressed in centimetres by a fraction having eight for its numerator and one, followed by eight ciphers, for its denominator could still affect the ear. To make a comparison with the limits of microscopic vision, the vibration that is just perceptible to the ear would have to be multiplied by one hundred before it could be seen by any possible microscope; or, put in another way, the sensitiveness of the ear is such that it could distinguish differences of pressure one hundred times less than the residual pressure of the best vacuum, which is to be measured in millionths or less of an atmosphere.
Early Traction Cables.—The first use of cables for transmitting power to a distance—telodynamic transmission—was made, according to Prof. W. Cauthorne Unwin, in 1850, at Lozelbach, Alsace, when some large factories which had been idle for nine years were started up again. The buildings were scattered at considerable distances apart, and there was only one steam engine. A steel band, working like an ordinary machine belt, was introduced for driving one of the factories about two hundred and fifty feet from the engine. It was mounted on pulleys a little more than six feet in diameter and making one hundred and twenty revolutions per minute, and was used for eighteen months, transmitting twelve horse power. On the suggestion of an English engineer, a wire-rope cable, a quarter of an inch in diameter, was then substituted for the band, while the same pulleys were used, with grooves turned in the rim to hold the cable—till after a few years they were replaced by pulleys of iron. A transmission to a distance of seven hundred and fifty feet was next arranged, with cables running on pulleys ten feet in diameter, at a speed of about fifty feet per second, and transmitting forty horse power, which, with pulleys at mid-distances, are still in use. The amount of work transmitted by a cable is proportionate to the amount of effectual tension in the cable and its speed. The strongest material should be used for the cables, and they should be run at the highest practicable speed. The largest cables which it appears practicable to use are about one inch in diameter. In order that the bending stress may not be excessive, the pulleys are of large diameter, usually from twelve to fifteen feet. Gutta-percha, soft wood, and leather have been used for the throat of the pulley, on which the rope runs. The greatest speed at which it is practicable to carry the rope depends upon the centrifugal tension of the pulley, and is usually about one hundred feet per second. With pulleys from three hundred to five hundred feet apart, a one-inch rope will transmit about three hundred and thirty horse power.
Dahlias and "Cactus" Dahlias.—The first dahlias seen in Europe grew in the Botanical Gardens at Madrid, in 1789, from seeds sent from Mexico. The flowers were "single" and had eight rays disposed in a circle around the yellow disk. The first double forms were produced in Louvain, Holland, in 1814, after three years' work. All members of the composite family that have been through the process of doubling and have enough flexibility to entitle them to extended cultivation exhibit, Mr. Wilhelm Miller says in the Bulletin of the Cornell University Experiment Station, at least three strongly marked tendencies—to reproduce single forms; to develop large globular flowers that are completely double; and a tendency toward what are called pompons. The single varieties are the most natural and the easiest to produce and fix, while the large-flowering and pompon varieties are to a greater extent products of art. The large-flowering varieties are the hardest to produce and the most uncertain. These somewhat conventional and artificial forms are still supposed to be essential to the nature of the dahlia; but they are not. In the evolution of the dahlia too much attention has been paid to color and not enough to form. The twelve hundred varieties catalogued in 1841 "were too much like twelve hundred variously painted balls of two sizes. No new or original idea found place in the evolution of the dahlia till 1873, when the first "cactus" dahlia, Juarezii, was produced. Instead of short, stiff, artificially formed rays, it has loose, flat rays with pointed or twisted ends, and the peculiar red that is associated with the cactus. Other colors have since been developed, which are not that of the cactus, and that part of the name of the class is no longer appropriate. Only the rays have been cultivated, while the disk flowers have been neglected. In the chrysanthemums, by cultivating both, a bewildering variety of forms have been obtained. It may be many years before the disk flowers of the single dahlia can be drawn out to so great a length as in some of the chrysanthemums; "but it can be done, and there is no reason in the nature of things why we should not have a race of dahlias analogous to the anemone-flowered chrysanthemums." The chrysanthemumlike forms are already some of the best we have.
Animals' Stores.—A writer on Animals in Famine observes in the London Spectator that if we examine the stores made by most of the vegetable-eating animals that lay by a "famine fund," we shall find "a rather curious similarity in the food commonly used by them. They nearly all live on vegetable substances in a concentrated form—natural food lozenges, which are very easily stored away. There is a great difference, for example, between the bulk of nutriment eaten in the form of grass by a rabbit and the same amount of substance in the ‘special preparation’ in the kernel of a nut, or the stone of a peach, or the bulb of a crocus, off which a squirrel makes a meal. Nearly all the storing animals eat ‘concentrated food,’ whether it be beans or grain, hoarded by the hamster, or nuts and hard fruits by the squirrel, nuthatch, and possibly some of the jays. But there is one vegetable-eating animal whose food is neither concentrated nor easy to move. On the contrary, it is obtained with great labor in the first instance, and stored with no less toil after it is procured. The beaver lives during the winter on the bark of trees. As it is not safe, and is often impossible, for the animal to leave the water when the ice has formed, it stores these branches under water, cutting them into lengths, dragging them below the surface, and fixing them down to the bottom with stones and mud. This is more difficult work than gathering hay."
Ancient Man in the Delaware Valley.—At a joint session of the Geological and Anthropological Sections of the American Association, held for the discussion of the Evidences of the Antiquity of Man in the Delaware Valley, Professor Putnam gave a general review of the whole subject and of the statements made by Dr. Abbott in 1883 of the finding of supposed palæolithic implements in the gravels near Trenton, N. J. The more important of the facts brought up have already been noticed in the Monthly. During the investigation of the region under Professor Putnam's supervision, in which every foot of the tract{—}half a mile long and one hundred feet wide—was dug over, photographs were taken of the chipped stones as they were found in situ in the sand and clayey deposits. These photographs and the specimens themselves were exhibited to the sections. While himself convinced that the argillite implements found in this site were the work of men anterior to the Indians, he had invited other archæologists and geologists to visit the place and investigate for themselves. Several had done so, and had reached conclusions similar to his and Dr. Abbott's as to the antiquity of the argillite remains. Papers were read by G. N. Knapp, H. B. Kummel, Prof. Thomas Wilson, Dr. H. C. Mercer, and Prof. R. D. Salisbury substantially in agreement with these views. Prof. G. F. Wright held that the formation of the clay indicated the action of water, thus further attesting the great antiquity of the find. Prof. W. H. Holmes held that the implements simply indicated the beginning of the Indian in that region. He thought the sand was piled up by the action of the winds, but did not touch upon the presence of the clay.
Ingenuity in Bow Making.—To establish the point that environment is not the cause but the occasion of industries, and that the true source of all arts must be sought in the ingenious human creature, Prof. O. T. Mason cites the fact that the withholding or the concealment of gifts by Nature acts as a stimulus to ingenuity. "Take, for example, the bow. There are regions where the wood for this implement is perfect, as in South America or the hard-wood forests of the eastern United States. Here the very embarrassment of riches leads men to be satisfied with a very poorly made bow. Now, the characteristics of a good bow are rigidity and elasticity. When our ingenious friend the Indian climbed the eastern slopes of the Rocky Mountains away from the hardwood forests, he invoked the mammals to yield the sinew from the leg or the scapula, and with this he glued an elastic back upon his poor implement or united two or three horns so as to get his effect, the middle piece giving the columnar resistance, the wings putting to flight the arrow. By and by you approach the hyperborean man and ask him how he is going to have a bow. It is true that he has only brittle driftwood, that glue will not hold in his cold and damp clime, and that materials for arrows are scarce. The result of this is the sinew-backed bow and the harpoon arrow, together the most complicated and ingenious device ever contrived by a savage mind. The bow wood has one virtue, that of rigidity. By an ingenious wrapping of hundreds of feet of fine sinew thread or braid from end to end along the back with half hitches on the limbs at every danger point the virtue of elasticity is added, and you have one of the most quickly responsive implements in the world. The arrow is quite as cleverly conceived."
Value of Pure Mathematics.—The presidential address of Prof. A. R. Forsyth in the Section of Mathematical and Physical Science of the British Association related to the value of the study of pure mathematics aside from the consideration of any applications that may be made of it. By some, mathematical study is regarded as useful only as it affords means for arriving at results connected with one or other of the branches of natural philosophy; by others, as it may possibly apply to practical issues. To the former class of critics the author cited instances in which the utilitarian bias in the progress of knowledge has not been the best stimulus, or in the long run the most effective guide toward securing results; to the others he maintained that mathematical students are justified in not accepting practical issues as the sole guide by the consideration that such issues widen from year to year and can not be foreseen. Moreover, if such a principle was adopted many an investigation undertaken at the time for its intrinsic interest would be cast aside unconsidered, because it did not satisfy an external test that really had nothing to do with the case, and might change its form of application from time to time. Among instances in which the purely mathematical discovery preceded the practical application and was not an elucidation or an explanation of observed phenomena, are cited the principles of conic sections, known to the Greeks two thousand years before Kepler and Newton found in them the solution of the universe; the methods of analysis by the application of which the discovery of the planet Neptune was attained; the reasoning on the properties of wave-surfaces by the use of which Sir William Hamilton inferred the existence of conical refraction; and the theory of functions, in which the purely mathematical interest was deemed supreme, which has found application in the investigations of Lagrange and others on the construction of maps; in investigations on discontinuous two dimensional fluid motion in hydrodynamics; in the dynamics of a rotating heavy body, in various questions in electrostatics, and in some of the recent advances in physical astronomy. In the field of natural philosophy mathematics will furnish more effective assistance if in its systematic development its course can freely pass beyond the ever-shifting domain of use and application.
Curiosities of Zoölogy.—Prof. L. C. Miall observes, in his sectional address at the British Association, that zoölogists may justify their favorite studies on the ground that to know the structure and activities of a variety of animals enlarges our sense of the possibilities of life. Surely it must be good for the student of human physiology, to take one specialist as an example of the rest, that he should know of many ways in which the same functions can be discharged. Let him learn that there are starfishes whose nervous system lies on the outside of the body, and that in other animals it is generally found there during some stage of development; that in certain animals the circulation reverses its direction at frequent intervals; that there are animals with eyes on the back, on the shell, on limbs and limb-like dependencies, in the brain cavity, or on the edge of a protective fold of skin; that there are not only eyes of many kinds with lenses, but eyes on the principle of the pinhole camera without lens at all (nautilus), and of every lower grade down to mere pigment spots; that auditory organs may be borne upon the legs (insects) or the tail; that they may be deeply sunk in the body and yet have no inlets for the vibrations of the sonorous medium (many aquatic animals). It is well that we should know of animals with two tails or with two bodies permanently united; of other animals developed within a larva which lives for a considerable time after the adult has detached itself (some starfishes and nemertines); of animals which lay two or three kinds of eggs; of eggs which produce two (an earthworm) or even eight embryos apiece; of males which live parasitically on the female, or even undergo their transformations, as many as eighteen at a time, in her gullet; and of female animals which are mere bags of eggs. The more the naturalist knows of such strange deviations from the familiar course of things the better will he be prepared to reason about what he sees, and the safer will he be against the perversions of hasty conjecture.
The Life of the Toad.—From a study of the toad, by Mr. A. H. Kirkland, we learn that in this region it usually emerges from its hibernating quarters during April. Cold weather retards its movements, but on warm days in the spring the toads make their way to the ponds and stagnant pools. Mating is begun as soon as the water is reached, or even before, and in a few days the long slimy "ropes" of eggs deposited by the female may be found in the pools. The eggs are nearly black, and rapidly increase in size. In two weeks the young tadpoles are clearly outlined, and in three or four weeks the eggs hatch. The vegetable detritus of the pond bottoms and the slime and algæ attached to sticks, planks, etc., seem to be the common food of the tadpole. Warm weather favors the growth of the tadpoles, and usually the young toads are fully developed, leave the water, and spread over the fields. At this stage they are extremely sensitive to heat, and secrete themselves under leaves, stones, rubbish, etc., during the day; but after a hard shower they come out by thousands. Observations of the toad's feeding show that eleven per cent of its food is composed of insects and spiders beneficial or indirectly helpful to man, and eighty per cent of insects and other animals directly injurious to cultivated crops or in other ways obnoxious to man. Their stomachs can accommodate enormous quantities of food, and one will consume in twenty-four hours an amount equal to that required to fill the stomach four times. It is estimated that in one season a toad might destroy cutworms which would otherwise have damaged crops to the extent of $19.88. The toad thus renders conspicuous service to farmers, and gardeners and greenhouse owners could make it of special use. As there are laws for the protection of insectivorous birds, why should there not be as stringent legislation against the destruction of toads? If merit of service rendered to man be the standard by which legislation is determined, the toad presents a record which will compare favorably with that of any insectivorous bird.
Magnitude of Mexican Ruins.—Of the ruins of ancient cities in Mexico which Mr. W. H. Holmes has examined and described in his publications respecting them in a comprehensive scientific manner, none, perhaps, are more remarkable and extensive as a whole than those near the city of Oaxaca. Many of the important works here are found on mountain tops, "and one soon comes to recognize the notched profiles of the ridges and peaks that border the valley as being due to the strangely directed enterprise of the ancient inhabitants. The feeling of surprise induced by this discovery is followed by one of amazement as the real nature of the work dawns upon the mind. As the explorer climbs the slopes and picks his way from summit to summit, he is fairly dazed by the vast array of pyramids and terraces, which not only crown the heights, but overspread the steep slopes, destroying traces of natural contour and making the mountains actual works of art." Climbing one of the larger pyramids of the group on the summit of Monte Alban, the author obtained a magnificent panorama of the mountain and the surrounding valleys and ranges. "Turning to the north, the view along the crest was bewildering in the extreme. The crest of Alban, one fourth of a mile wide and extending nearly a mile to the north, lay spread out at my feet. The surface was not covered with scattered and obscure piles of ruins, as I had expected, but the whole mountain had been remodeled by the hand of man until not a trace of natural contour remained. There was a vast system of level courts inclosed by successive terraces and bordered by pyramids on pyramids. Even the sides of the mountain descended in a succession of terraces." But San Juan Teotihuacan, twenty-five miles northeast of the capital, in the magnitude of its remains and in the evidence the site furnishes of population and antiquity, "easily stands at the head of the ancient cities of Mexico. It lacks the well-preserved, sculpture decorated buildings found elsewhere in Mexico and Central America"; . . . but if the entire mass of the ruined structures of either Chichen, Uxmal, or Mitla was to be heaped up in a single mound it would hardly surpass the great Pyramid of the Sun alone in bulk, and the whole bulk of the Teotihuacan remains is many times that of its chief pyramid."
Significance of the Totem.—The Import of the Totem was the subject of a paper read by Miss Alice C. Fletcher before the Anthropological Section of the American Association. The Omahas have two totems, the social and the individual. In the course of the ceremonial attendant upon reaching puberty the young man fasts till he falls into a trance. If he sees or hears anything while in that condition, that becomes the medium through which he obtains supernatural power. He must seek and slay the animal he saw and preserve some part of it. This memento is his totem. Its efficacy is based on the Omaha's belief in the continuity of life, which links the visible to the invisible, binds the living to the dead, and keeps unbroken the thread of life running through all things, making it impossible for the part and the entirety to be dissociated. Thus one man could gain power over another by obtaining a lock of his hair. The totem opens a means of communication between man and the various agencies of his environment, but it can not transcend the power of its particular species; consequently all totems are not equally potent. Men who see the bear are liable to be wounded in battle. Winged forms give the faculty of looking into the future and controlling coming events, while thunder gives ability to control the elements and authority to conduct certain religious rites. The simplest form of the social totem is in the religious societies, the structure of which is based upon the grouping together of men who have received similar visions. Applied to the gens, or tribal body, the object of the totem was to teach the people the knowledge and duties of kindred, and one of the most important of these duties was the maintenance of the union of the tribe. The gentile totem gave no immediate hold upon the supernatural, as did the individual totem to its possessor. Outside of certain rites it served solely as a mark of kinship, and its connection with the supernatural was manifest only in its punishment of violations of the taboo. Its inculcation was that the individual belonged to a definite kinship group, from which he could never sever himself without incurring supernatural punishment.
The Moon and the Sabbath.—The Rev. R. J. Floody presented to the American Association the results of ten years' research into the origin of the week and holy day among primitive peoples. He found that they were widespread among the nations of the ancient world from very early times. Each of these peoples is assumed to have independently originated the Sabbath and not to have received it second hand from other tribes. To account for the unanimity in observing this universal custom among so many races, we must look for its source in some pheomenon of Nature common to all. The prominence of seven as a sacred number among ancient peoples is due to the moon. Each lunation has four phases or quarters, averaging about seven days apiece. Nature worship was the earliest form of worship among primitive peoples, and the moon took precedence among objects of Nature. When the new phase of the moon appeared, men worshiped it, showing their honor and respect by sacrifices and then a feast. They would naturally rest from labor most of the time to give attention to the feasts. Work on the sacred day was considered inauspicious. This early week was the rough and ready reckoning of men devoid of the use of astronomical instruments. The holy day was not the seventh day of time, but the seventh day of the moon. The difficulty of getting the exact number of days of the lunar week to fit into the lunar month led to the substitution in some of the nations of three weeks of ten days each. The author substantiated his theory by citations from the literature and traditions of many peoples.
Hindu Godlings.—The godlings or inferior deities commonly worshiped by the masses of the Hindus, and described in Mr. W. Crooke's book on the Popular Religion and Folklore of Northern India, are of very different character from the exalted conceptions of divinity described in the Vedas and known to the select among high-caste Brahmans. They are very numerous, and are described under the five headings of the godlings of Nature, heroic and village godlings, the godlings of disease, the sainted dead, and the malevolent dead. The godlings of Nature include the sun, the moon, the demon of the moon's eclipse, the rainbow, the Milky Way—known also as the pathway of the snake or the course of the heavenly Ganges—Mother Earth, thunder and lightning, the sacred junctions of rivers, sacred wells and lakes, hot springs, waterfalls, sacred mountains, hail and whirlwind, aerolites, etc. The great rivers, especially the Jumna and the Ganges, stand very high in the list of benevolent Nature godlings. The heroic village godlings form a numerous class; and there seems to be confusion between some, of them and some Mohammedan saints in high repute. The current from a ventilator placed at the tomb of one of these saints to furnish fresh air to the pilgrims was believed by them to be his holy breath, and they went round to worship it. The godlings of disease are mostly goddesses, and are forms of Kali, the goddess of death. There is a goddess of cholera, and one of smallpox, but none of the plague; whence it is inferred that that disease is new to India. The belief in the good luck of horseshoes is common in India, and so is the custom of throwing rice after brides.
Classification of Fibers.—While engaged in cataloguing the fibers of the world, Charles Richard Dodge found that a better classification was needed, and has published the scheme which he devised. Besides the popular understanding of the term fiber as relating to those forms of filamentous substance that can be spun and woven or twisted into cordage, he would include under it rougher substances that are plaited. In his classification two groups of fibers are recognized, based on cell structure. The first group includes fibers with fibro-vascular structure, embracing three groups: bark fibers, derived from the inner bark of exogenous plants; woody fibers, comprising barked stems or twigs, roots, the split wood of exogenous plants, and wood-pulp; and structural fibers, derived from the structural system of endogenous plants. The second group—fibers of simple cellular structure—comprises surface fibers, including the down or hairs surrounding exogenous seeds or their envelopes; the hairlike growth found on stems, leaves, and buds; fibrous material produced in the form of epidermal strips from the leaves of palms, etc.; and false fibrous material—mosses and leaves used for packing, and certain fungous growths. It is the consideration of these useful native fibers that makes it possible to enumerate a thousand species of fibrous plants, while the world's commercial fibers would hardly reach a total of fifty species.