Popular Science Monthly/Volume 43/June 1893/Popular Miscellany

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POPULAR MISCELLANY.

The Telautograph.—A new system of electric transmission was recently exhibited in New York and Chicago which promises to rival in commercial importance the telephone. This is the writing telegraph of Prof. Elisha Gray. By means of it any one can with an ordinary lead pencil on ordinary paper write a message or make a sketch and have it reproduced with exactness, in its minutest detail, in the receiving instrument, which may be hundreds of miles away. As this method of communication necessarily provides a record, and as the mistakes so easily possible in any system of oral communication can not occur, it should find a wide field of usefulness in the business world. Fac-simile telegraphs are almost as old as the art of telegraphy itself, but no such system has heretofore come into extended use, as they have proved unreliable in practice and have lacked the simplicity essential in any apparatus designed for general use. Nearly all previous attempts to provide autographic reproduction have depended upon synchronism in the movement of the transmitting and receiving instruments, a condition practically impossible of realization. Unlike these earlier devices, the system of Prof. Gray does not depend at all upon the timed movements of the instruments at each end of the line, but like the telephone the transmitter positively actuates the distant receiver. The fundamental principle of the apparatus is that first applied to this purpose by Mr. E. A. Cowper, of England, some fifteen years ago; but Prof. Gray has greatly simplified the construction and given a range and flexibility to the instruments which practically constitutes a new departure in this method of transmission. The principle involved is the familiar geometric one that any plain curve, no matter how intricate, may be decomposed into component parts along two lines at right angles to each other. If, then, a point be affixed at the junction of these lines, all that is necessary to reproduce its movements is to cause two other similar lines to reproduce the movements of the first two. A point at the junction of the second lines will then travel in exact conformity with the first point. This principle is made use of in the familiar draughtsman s instrument, the pantograph, used for producing enlarged or reduced copies of an original drawing. In Prof. Gray's apparatus the transmitting instrument consists of a box provided with a leaf or table, upon which the paper, which is fed from a roll mounted upon the instrument, rests. The pencil is placed at the junction of two silk threads at right angles to each other, the farther ends of which are wound upon drums in such a way that the motion of the pencil serves to rotate them backward and forward in exact accordance with the linear components of the curves described by it. These drums have each an arm which sweeps over a series of electrical contacts, thereby sending a succession of electrical impulses into its line wire proportional to its movement. A contact playing between stops serves to reverse the current with the reversal of the motion of the drums. The receiving instrument consists of a pen mounted at the junction of two light metal arms, the movements of which are controlled by the electrical impulses sent to line by the transmitting mechanism. This control is effected by means of a gear-wheel.—one for each metal arm—which is actuated by clutch-weights, which weights are in turn controlled by the current through the medium of an electro-magnet. The gear-wheels, therefore, move in one direction or the other in exact accordance with the currents sent over the line wires and give motion to the arms carrying the transcribing pen. The pen is of the ordinary form in such instruments, namely, a glass tube drawn out to a capillary bore near the point and supplied with a free-flowing ink.

 

Relations of Leaves and Boots.—As a result of investigations of the influence of manure on the development of roots, M. Dehérain has found that roots in unmanured ground have a larger growth than in manured, having to spread more in search of the scanty nutriment. It having been previously found that transpiration largely depends on the activity of the roots as well as on the evaporative surface, and is not, therefore, strictly proportional to leafy development, it follows that if a plant with small leafy growth evaporates relatively more water than one with more abundant foliage, it is probably due to large root-growth procuring more water. Volkens has observed that desert plants have extraordinarily long roots. M. Dehérain further points out that solar rays falling on a plant have the twofold work of assimilation and transpiration to perform, and that these are complementary. In strong, leafy plants, assimilation is vigorous, so that transpiration is limited; while in the leaves of an "anæmic" plant a large fraction of the solar energy is given to transpiration.

 

Folk Lore of the Kootenay Indians.—Among the Kootenay Indians of southeastern British Columbia there exist some strange ideas of mythology. Their folk lore is extremely picturesque, and bears strong resemblance to that of the earlier European and Asiatic races. The moon is regarded by them as a man, and the sun (natā-nik) as a woman. There was no sun in the beginning (according to the Kootenay-Indian mythology), but after the Indians had vainly endeavored to discover it, the coyote was successful in making it rise above the mountains. Another version makes the chickenhawk cause the sun to rise, and the coyote, getting angry, shoots an arrow which misses the sun, and causes the prairie to take fire. The man in the moon is an Indian, who chopped wood every day, including Sunday, whereupon the moon came down and seized him, and he has been up there ever since. In the same manner the stars are supposed to be Indians, who have "got up into the sky" from time to time; thunder is caused by a great bird, and the lightning by the arrows which it shoots. Their version of the flood is a very quaint piece of folk lore, and apparently entirely original with them. In a report of the British Association for the Advancement of Science, on the Northwestern Tribes of Canada, Mr. A. F. Chamberlain describes this legend very interestingly, and in his pamphlet, which covers almost every trait and characteristic of the Kootenays, as well as statistics of the development of their language and customs, he relates the strange history of their sociology, folk lore, physical characteristics, etc. The monograph is published at the offices of the association at Burlington House, London.

 

Animals for Pets.—What is required for an every-day pet, says the London Spectator, is that it shall be beautiful and intelligent; that it shall neither be too large nor too delicate; and, if a bird, that it shall sing or talk—preferably both. The limits set by size and constitution are the main consideration in the choice of pets. Yet even so, the possible range is very great, and might well extend far beyond the species which form the main body of those usually seen at home. Tame rabbits are plenty, but tame hares are rare. A charming little foreign pet for the house is the suricate, "an active and vivacious little fellow, some ten inches long, with greenish-brown fur, large bright eyes, a short pointed nose, and dainty paws, which, like the squirrel's or the raccoon's, are used as hands, to hold, to handle, and to ask for more. . . . The creature is made for a pet, and is so affectionate to its master that it can undergo any degree of 'spoiling' without injury to its temper." A larger and more beautiful creature is the brown opossum from Tasmania—the "sooty phalangist"—with fur of the richest dark brown covering its prehensile tail like a fur boa. "Its head is small, with a pink nose and very large brown eyes; and it has a 'compound' hand, with claws on its fingers, and an almost human and clawless thumb, with the aid of which it can hold a wineglass, or eat jam out of a teaspoon. That owned by the writer was, without exception, the most fearless and affectionate pet he has ever known. In the evening, when it was most lively, it would climb on to the shoulder of any of its visitors, and take any food given it. It had a mania for cleanliness, always 'washing' its hands after taking food, or even after running across the room, and was always anxious to do the same office by the hands of any one who fed it. It made friends with the dogs, and would 'wash' their faces for them, catching hold of an old setter's nose with its sharp little claws, to hold it steady while it licked its face. The staircase and banisters furnished a gymnasium for exercise in winter, and in summer it could be trusted among the trees in the garden." The American gray squirrel, the coati, the mongoose, the marmot, and the prairie dog are commended as pleasant pets in their various ways; but only one monkey—the capuchin—is thoroughly recommended as an indoor pet. No other monkey approaches it in good temper and pretty, winning ways. They all have good, round heads, with black fur on the top and light brown on the cheeks. Their faces are most expressive and seldom still, for they take deep and abiding interest in everything in or about their cages. One is mentioned which had learned to put out burning paper by beating it with its hands or knocking it against the floor. Another, if it got a match, would collect a heap of straw, strike the match, light its bonfire, and dance around it. "The capuchin is so small, so pretty, and so clever that it seems to embody all the good and none of the bad points of monkey nature."

 

Spinal Curvature in Schools.—The result was recently presented by Dr. Scudder, of Boston, of an investigation into the seating of thirty-five hundred schoolgirls, with especial reference to its effect on the spine. Lateral curvature of the spine, the author said, is probably due to several factors, among which are the weight of the body falling upon a weakened spine; weakness of the spine in bone, muscle, or ligament; and a position persistently out of the median antero-posterior plane of the body. The author had made a careful examination of the seating in schools, and found that faulty positions are certainly induced because of the lack of adaptation of seat to pupil and of pupil to seat. It was not possible to say how much of a factor poor seating is in causing lateral curvature, but there could no longer be any doubt that it plays an important part. He favored as a counteractive measure the introduction of general neutral movements tending to develop the whole child along the lines of his natural muscular evolution, or exercises like those of the Swedish gymnastic system. Some of the participants in the discussion of the reading of the paper suggested that faulty school attitudes might be less potent in producing curvature than bad habits acquired independently of them. All agreed upon the utility of suitable exercise as a counteractive.

 

Contrasts in Mountain Scenery.—Writing in Appalachia from the New Hampshire mountains of his visit to the Sierra Madre Mountains, Mr. Charles E. Fay begins by describing the contrast between the two scenes, than which, he says, there can hardly be a greater one. "The cool, balsamic air, the morning sky already piled with cumulus cloud prophetic of showers in mid-afternoon, the green fields cut by teeming brooks undulating away to meet the darker forest green that drapes the varied shapes of Whiteface, Passaconaway, Paugus, and the lower slopes of Chocorua, are a striking antithesis to what we looked on there. These mountains woo you, and there is an anticipated satisfaction in the promise made yourself to stand on every one of the peaks within your range of vision, attaining them by pleasant journeys through ferny, mossy, pathless woods. But in southern California the mountains do not invite one—at least, not for their own sakes. The conditions of climbing are most unfavorable. The summer heat is intense. They lie beyond an unattractive stretch; for the grass and flowers that in spring cover in wonderful profusion the ground that slopes upward to the sudden beginning of the steep foothills have withered, and in July all is parched and barren. The scattered live-oaks in the foreground, domineered by the will of the prevailing wind, have a half-frightened air; nothing of the repose of our maples, oaks, and white pines. The mountains themselves, rising with an almost monotonous uniformity of grade, are also burned as dry as a cinder, their dead-white rocks pallidly reflecting the remorseless sunlight. Not until near the summits or deep in the cañons do you find forest trees. The dull vegetation of the slopes of lesser altitude is of a shrubbery hard to penetrate, the most common sorts being a so-called greasewood (not the plant known in Colorado by that name) and a disagreeable thorn-bush, which, however slightly broken as you force your way through it, gives forth a sticky, milk-white juice; less frequent is the Manzanita, its smooth, reddish brown being prettier to the eye than yielding to the push." These slopes abound in rattlesnakes, and there are myriads of lizards or "swifts."

 

Amenities of Scientific Controrersy.—Says the Independent, April 20, 1893: "Not on the ground of Incompetency, but on the ground of courtesy and decency, we will say that there ought to be a certain overhauling of the United States Geological Survey. Our attention has been called to articles in the American Anthropologist and the Literary Northwest by William J McGee, member of the Geological Survey, criticising a geological work recently written by a competent gentleman not connected with the Survey, but who has given great attention for many years to surface geology. This review is sprinkled with such words, applied to the author of this volume, as 'idlers,' 'pitiable paupers,' 'swindle,' 'harpies,' 'parasites,' 'shyster,' 'gull,' 'vulture,' and 'betinseled charlatan.' It is a long while since we have seen so indecent an article."

 

The Channels of Mars.—A new explanation of the channels of Mars is offered by Mr. T. W. Kingsmill, of Shanghai, China, as follows: As Mars revolves round the sun, under the rule of gravitation, it must have tides on its surface; and since its moons are not sufficiently large to cause any sensible rise, its tides must be mostly solar. Now, the best views we have of this planet are when it is in opposition—that is, when we are interposed between it and the sun, so that we should always see it best at high tide. The writer then makes rather a strong point of the great eccentricity of the orbit of Mars, and the consequent heavy fall it makes when plunging toward the sun. Situated farther from the sun than we are, Mars must be regarded as an older member of our system; and since it is smaller than the earth, it is only natural that its surface crust should be thicker than that of our planet. Granting this, then the internal pulp would not have such a power to compensate for the rapid fall as the earth does internally, for there would not be so much of it, so that an external compensation, assuming the crust to be too thick to alter its form, would have to take place at the surface. On the surface, of course, the water is the only power; therefore we should expect, to put it in Mr. Kingsmill's own words, "that the water in the ocean would be projected into the Martial hemispheres, and as the planet approached the sun, tides would sweep round the planet; that the canals should sometimes appear and>sometimes be duplicated. . . is only, a priori, what might be anticipated."

 

Factors of a River's Character.—Where a river shall go, what kind of a channel it will cut, how much work it will do, says A. P. Brigham, in his paper on Rivers and the Evolution of Geographic Forms, are matters determined, in an infinite number of ways, by the underlying strata. A river flowing on horizontally bedded rocks will tend to have, in its youth, a narrow cañon. Alternations of hard and soft strata give, in early stages of river life, alternations of rock benches and talus slopes; and many terrace-like horizons on the sides of the valley mantled commonly by soil, have this origin. Thus a terrace may be built up or carved out, and it may consist of alluvium, glacial rubbish, or bed rock. Tilted rocks give different types of river valleys in infinite variety. These types may be said to be just now beginning to attract a fair share of the interest of geographers and geologists. They will, in years to come, afford some of the most intricate as well as most fascinating problems which are open to inquiry.

 

The Critical Point in a Thunderstorm.—The belief that danger from lightning ceases as soon as the rain begins to fall heavily—expressed in the words of a mother reassuring her children, "Don't cry any more, God is sprinkling the earth with holy water"—prevails extensively among the Flemish peasants. Usually, according to M. P. J. De Ridder, lightning flashes from storm-clouds at the line between the heavy rain of large drops and the finer rain—or from the edge of the heavy rain. This is always the case in cumulo-nimbus storms, and as the number of storms of that kind exceeds all others, the belief of the peasants is at least worthy of attention. In nimbus storms, on the other hand, the critical point is at the latter end. In those of them which are developed in the veil of strato-cirrus, as when the sky is slowly covered, the rain falls at first without intensity and increases gradually, with distant thunder, while the storm itself does not seem to make much headway. But suddenly the rain falls more rapidly, and the dangerous moment has come. The roar of the thunder becomes terrible, the storm ceases, and the sky is cleared.

 

The Agaves.—The name of aloes is commonly given to plants of peculiar appearance which have long, fleshy leaves, with spines on their tips and sides; but this does not explain why the name has been given to species to which it does not belong, such as the agave, which do not resemble them. In Central America, their real country, where they have been cultivated on a large scale from the most remote times, they are called pitu, ozal, istle, metl, maguey, etc. Probably, soon after the discovery of America, a species of agave was introduced in the south of Europe, and became quite at home there. Linnæus, not realizing that all the agaves are American, gave it the specific name of Agave americana. Now there are more than a hundred species on horticulturists' catalogues, but many of these are only varieties. The uses to which these plants are found applicable are constantly increasing. In the United States and Europe they are only garden ornaments. In Mexico they hold the first place as wine plants and as textile plants. The filamentous substance obtained from their leaves is known all over the world as aloes fibers. These fibers, of length and thickness depending on the variety and locality, are so elastic and durable as to be in great demand for ropes, brushes, harness, and coarse woven goods. The national drink of the country—its wine and cider, there called pulque—is produced from this plant. When pulque not yet wholly fermented—then called agua miel or maguey juice—is properly distilled, an alcoholic drink called mescal is obtained. The plants are cultivated on a large scale in the lower and middle lands of which the agave is native, and the consumption and exportation have attained a great development. The maguey enjoys the advantage of flourishing where nothing else can grow; and immense tracts of sterile soil on the sea coast have been, under the stimulus of profit, made to produce remunerative crops. Yet the plant does not reject fertilizers, and those containing potash have been found very good. The elevation and climates of the several provinces varying considerably, many kinds of agave are cultivated, according to their adaptations, and have been given as many local names, which are Aztec or Spanish. Some ten varieties are adapted to produce fibers of henequen, or Sisal hemp—long, silky, elastic, and durable fibers suitable for rope-making or for coarse woven fabrics. Other varieties called lechuguilla in Mexico, having shorter and coarser fibers, furnish acceptable substitutes for hog's bristles in brush-making. These fibers are called istle or tampico. The thick and fleshy part of the root of some of these agaves—called amole—is used for soap, and when roasted furnishes what is considered a "savory food." The Agave americana is planted in Algeria for hedges. The dry flower stalks furnish materials for light buildings; and the pliant pith is made into insect paste and dressing for razor strops.

 

The Danger of the Celluloid Button.—An instance is related in England in which a lady was put in great danger while standing before a bright but not blazing fire by the burning of one of the fancy celluloid buttons of her dress. Experiments made by Prof. C. Vernon Boys prove that articles composed of this material are very susceptible to heat and take fire very readily. Prof. Boys advises the public to guard themselves from what is likely to be a grave source of harm, even to the extent of fatal issues, by taking the precaution of submitting to a very simple test that resembling tortoiseshell, hairpins, combs, and other ornaments, and toys. On briskly rubbing the button on cloth a strong smell of camphor is evolved. If this ready test fails, a small portion may be ignited; it will burn energetically with a flaring noise, and the fumes of camphor given off can not be mistaken. If the article is composed of other material, the smell will probably bring to remembrance that produced on burning feathers. Celluloid, it is said, may be made uninflammable and safe by mixing with it certain metallic salts—among them the chloride of tin.

 

Evolution of the Color of Birds.—Mr. Charles A. Keeler, of the California Academy of Sciences, has published a volume of 336 pages on The Evolution of the Colors of North American Land Birds. In explanation of how he arrives at the theories which he advances he quotes the experiments and researches of many celebrated scientists on the evolution of the colors of butterflies, goldfish, spiders, etc., and dwells particularly on the effects of climate and the laws of heredity—uninterrupted transmission, sexual transmission, and mixed or mutual transmission—as the chief elements in the evolution of the coloring of birds' plumage. Remarking, en passant, that the plumage of birds, confined or diseased, loses its brilliancy, and that, should the confined wild bird breed, the plumage of the offspring would be of less beautiful colors than the parent, Mr. Keeler cites Mr. Darwin, who says: "Each of the endless variations which we see in the plumage of our fowls must have had some efficient cause; and if the same causes were to act uniformly during the long series of generations on many individuals, all probably would be modified in the same manner." And in relation to the fact that there is a general constancy of coloration in the wild birds, he remarks that this uniformity of coloration is preserved by free intercrossing, and where this is prevented by isolation or migration, variations of color very frequently take place. Young birds of various species, after the autumn molt, continue through the winter to assume, by degrees, the more intense colors characteristic of the adults, without changing feather; and Mr. Yarrell says that many birds appear to become more brilliant in color as the breeding season approaches, without either molting or the wearing away of the tips of the feathers. Of the effect of food and environment upon the colors of bird plumage, Mr. Keeler believes that the direct influence of the environment plays an important part in the evolution of colors, and regarding food he quotes Mr. Frank Beddard, who says in Animal Coloration: "If the nature of animal colors is borne in mind, it seems impossible to doubt the modifying action of food; those that are due to structural peculiarities of the parts colored (e. g., feathers of many birds), may be altered just as much as those that are caused by the deposition of pigment; for the 'structural' colors depend largely upon pigment for their manifestation. . . . When there is an obvious relation between waste matter and the skin pigments, it can not be doubted that variation only in the amount of the food may lead to color changes." 8ome interesting color evolutions are given in the chapter entitled The Direct Influences of the Environment; for instance, if a yellow canary is fed with cayenne pepper, it will cause the feathers to turn red; carmine was given to some canaries and the yellow feathers became white; while Amazon parrots change from green to yellow when fed upon the fat of certain fishes. Notwithstanding the exhaustive manner in which Mr. Keeler has treated the subject, he says that "the paper is written more with the hope of stimulating thought, and Inciting in a new and as yet almost untrodden field of ornithological inquiry, than with the expectation of reaching definite results."

 

Behavior of Young Snakes.—One of the most curious matters connected with the breeding habits of certain snakes is the "egg-tooth," a small tooth fixed to the united premaxillary bones, and projecting slightly forward, beyond the edge of the upper lip. It is present only in the embryo, and is shed very shortly after the escape of the young snake from the egg. This tooth is employed by the little snake in ripping open the tough egg-covering in its efforts to escape from its prison. The young of the Heterodon (a snake closely allied to the copperhead) are perhaps the most amusing youngsters of the snake family. In Volume XV of the United States National Museum, O. P. Hay, in a paper entitled On the Breeding Habits, Eggs, and Young of Certain Snakes, gives a very interesting account of the singular habits of the young Heterodon from personal observation. Having received a consignment of twenty-seven eggs, which were supposed to be those of the copperhead snake, he watched the bursting from the tough, parchment-like egg-covering of the young snakes, and exactly eight days after the receipt they were all hatched, the length varying from seven to eight inches. "From the moment of escape from the egg all were quite active and manifested the characteristics of the adults. . . . A faint hiss was uttered, but that may not have been voluntary. One would sometimes flatten its head and body and rear up with the anterior third of its length from the ground. If one did not know well their inoffensive natures, one would be excused for fearing to handle them. An exceedingly singular habit possessed by the adults (which is also practiced by the young) is that of feigning death." On being struck or teased, they will roll over as if in the intensest agony, and then throw themselves on the back and lie there as if dead. If left undisturbed for a little while they would turn over and creep slyly away. In this paper Mr. Hay treats the peculiar appearance of the eggs of snakes, which bring forth their young alive, very interestingly, and it would seem that even in these also there is present th§ singular egg-tooth.

 

Precautions against the Lizard.—A superstition prevails among the Shuswap Indians of British Columbia that a man who sees a small lizard of a particular species is followed by it wherever he may go during the day, till at length, when he is asleep during the following night, it finds him, and, entering his body, proceeds to tear out his heart, so that he quickly dies. The late Mr. Bennett, of Spallumsheen, told Dr. Dawson in 1877 that the Indians employed by him in making a ditch for purposes of irrigation, on coming into camp in the evening, would jump several times over the fire in order to lead the possibly pursuing lizard to enter the fire and be destroyed in attempting to cross. He also noticed that they carefully tied up the legs of their trousers when retiring. If, while at work during the day, they saw one of these little lizards, which appeared to be abundant in that locality, it would be caught in a forked twig, the ends of which were then tied together with a wisp of grass, and the butt end of the twig afterward planted in the soil. Thus treated, the lizard soon died and became a natural mummy. If, during the progress of the work, any one found and carelessly tossed aside one of these lizards, the Indians would throw down their tools and search diligently until they found it and secured it in this manner. A similar belief to the one here recorded is noticed in Nature by Mr. C. Bushe, as prevailing in Ireland, with reference to water-newts, which are there called man-eaters. One woman to whom a specimen was shown, said they were known to jump down people's throats, to their certain destruction.

 

Life in Morocco.—The present population of Morocco, says Nature, is a puzzle almost as difficult, although on a smaller scale, as that of China. The authors, Lieutenant-Colonel Sir Lambert Playfair and Dr. Robert Brown, of the Bibliography of the country, give 4,000,000 as an estimate, but the guesses of various authorities vary between 1,500,000 and 15,000,000. The roads shown on the map are merely mule and camel tracks made by the feet of the pack animals, unaided by any engineer. Ferries are rare, and, of course, bridges are unknown in the interior. The distribution of towns and villages is often at variance with the rules holding for civilized countries. The villages are built out of the way of the main tracks, because people never travel in Morocco for the good of the inhabitants, and it is safer to live off the path of the tax collector and the government official, who demand free food and quarters. The great number of place-names on the map of so thinly peopled a country is due to the fact that the tombs of saints are such important landmarks that they must be indicated, even if only a few persons live beside them. All the places beginning with Sidi (Lord, Master) are either actually tombs, or the tomb has formed the nucleus of the town or village. "Sok," another affix of frequent occurrence, means market-place, and many of the established sites for periodical fairs are uninhabited between the gatherings of people from far and near. Many of the place-names on the coast exist in two forms at least—the native word and its Portuguese or Spanish translation; Casablanca and Dar-el-beida (both meaning white house), for example.

 

Sirius and its Companion.—The slight periodical displacements of Sirius, first observed about seventy years ago, were found by Bessell in 1851 to be due to its revolution in an ellipse, the largest diameter of which is 2·4″, which is accomplished in about fifty years. Sirius was therefore concluded to be a double star, with a satellite of considerable relative importance, which, as it was not seen, was supposed to be dark. The satellite, which is not quite dark, was seen for the first time in 1862; and can now, by taking proper precautions, be found at will. The period of revolution of the group has been determined by M. Auwers at forty-nine years and between four and five months, and the orbit an ellipse, the greater axis of which is 2·42″. Hence, according to the estimated distance of Sirius, the two stars are about twenty times as far apart as the distance of the earth from the sun, or equal to the distance of Uranus. The mass of the whole system has been computed to be 5·24 times that of the sun, of which Sirius has 2·20 times and the companion 1·04 time. The orbit of the companion is larger than that of Sirius. The distance apart of the two stars, now less than 4″, will diminish for two years longer, after which it will begin to increase again, till in twenty-six or twenty-seven years it will exceed 11″. The discovery of the system and of the rate of its revolutions affords proof of the operation of the force of gravity beyond the limits of the solar system.

 

Origin of Cholera.—All the theories of the origin of cholera, Mr. C. Egerton Fitzgerald suggests, may be right. The disease will eventually be found to be a miasmatic one, of which the hitherto undiscovered germ can be conveyed through the air, by water, excreta, infected bodies, and clothing. What the special germ may be we as yet know not; but that it multiplies with enormous rapidity under favorable conditions of heat, moisture, and dirt there can be no doubt. Each individual aa he is attacked becomes a fresh nidus, a hotbed for disease germs, which seek and require only a suitable soil or cultivating medium for their propagation; but a suitable condition of the atmosphere exists only under certain exceptional circumstances. This accounts for the rapid spread of cholera among large masses, especially dirty masses, of men. Each unit of infection acts on suitable media exactly as would a particle of yeast if introduced into a mass of fermentible fluid under the requisite conditions of temperature, etc. This is the explanation of the fact that, although cholera may arise sporadically anywhere, under favorable but exceptional circumstances, it is endemic only in India, where, presumably, these requisite conditions constantly prevail. That cholera does spread principally along the lines of human intercourse, that it may be conveyed by man, by water, by fomites, may be readily conceded without affecting the contention as to its miasmatic and aërial character and method of propagation. That cholera is caused by Koch's vibrio is to the last degree improbable, and certainly unproved, and the presence of that microbe in the dejecta of cholera patients may be due simply to its finding a congenial soil there.

 

Progress in Practical Electricity.—The recent inaugural address of Mr. W. H. Preece, as President of the English Institution of Electrical Engineers, was devoted to a review of the progress of the practical applications of electricity during the forty years of the speaker's service in developing them. He spoke first of the extension of the telegraph; then of the oceanic service of the Eastern Telegraph Company, the greatest cable corporation in the world, whose system of 25,370 miles stretched from Cornwall to Bombay, connected the northern and southern shores of the Mediterranean with Malta, and joined the various other islands of the Mediterranean and the Levant. This company, in conjunction with the Eastern Extension and the Eastern and South African Companies, also gained access to Australia and New Zealand on the one hand, and the Cape of Good Hope on the other, the combined mileage reaching a total of 47,151 miles. There was no more perfect apparatus in existence, the speaker said, than the lightning protector, and if it ever failed to do its duty it failed from man's neglect of some simple rule or his failure to keep it in proper order. In 1892 not an accident was recorded in any high-class telegraph instrument in the whole United Kingdom. To railways, electricity had proved an invaluable adjunct—in the repetition of signals obscured from the view of the signalman, and in night signals. The number of telephones in actual use might be put down at a million. The speaker had recently devised a new form of cable which would probably quadruple the rate of telegraphic cable working to America. There was no theoretical reason why we should not converse between London and every capital in Europe, while it was not impossible to speak even across the Atlantic. Heating and cooking apparatus worked by electricity had not at present a very favorable outlook, though many appliances had been shown in operation. The electric light was essentially the poor man's light. Many efforts were being made to utilize the waste forces of Nature in producing electric currents for the economical supply of the light. There were many towns whose streets could be brilliantly illuminated by the streams running past them. The range of power transmission had been enormously extended since much higher voltages than were possible with continuous currents could be employed. Meanwhile, power transmission by single-phase alternating current had also been developed. The use of electrically transmitted power in mines had been greatly extended within the last few years, especially in America, and the use of electrical energy for working railways was making gigantic progress in the United States, while it had begun to make a serious move in the United Kingdom.