Popular Science Monthly/Volume 18/March 1881/Popular Miscellany
POPULAR MISCELLANY.
Bone-Caves in Pennsylvania.—Professor Leidy in company with Dr. T. C Porter, of Easton, Pennsylvania, visited, in August last, Hartman's Cave, near Stroudsburg, Pennsylvania, on the invitation of Mr. T. D. Paret, of that place, and examined a number of interesting animal and other remains which were found there. The cave is partly filled with a bed of clay ten feet deep, on which rests a thin layer of stalagmite, and on this about a foot of black, friable earth mingled with animal and vegetable remains. The cave appears to have been too small to be inhabited by the larger carnivora, and no large entire bones of them were found, but about a half-bushel of fragments and splinters of limb-bones of smaller and large animals have been collected, many of which exhibit marks of having been gnawed, whether by rodents or small carnivora Professor Leidy does not assume to decide. Some of the splinters are derived from such large and strong bones that it is questionable whether even the largest carnivora could have produced them, and are presumed to be remnants of human feasts, in which the bones were crushed to obtain the marrow. A few of the bones are somewhat charred, among them a small fragment of a bison's jaw with a molar tooth. Most of the bones are of species still living, but some of them, as jaws of the reindeer, bison, and wood-rat, are of animals no longer belonging to the fauna of the State; and a few, as the teeth of the Casteroides Ohioensis, and the jaws of a young peccary (Dicotyles nasutus), are of extinct animals. None of the remains have been identified as positively pertaining to our domestic animals, unless two of the teeth may be those of a fœtal or new-born horse. The vegetal remains include a few small fragments of charcoal and seeds of dogwood, pig-nut, and walnut. Remains of human work were found—a large stone celt of hard brown slate, from the bone-earth some distance within the cave; five bone awls, some of them gnawed; the prong of an antler worked so as to be barbed on one side; a needle of bone resembling a crochet-needle; a fish-hook of bone; and a cone-shell, of a species' found on the western coast of Central America, bored through the axis as a head. Professor Leidy has, since exploring this cave, examined a collection of bones in the Museum of the Philadelphia Academy of Natural Sciences, which were found more than thirty years ago in the Durham Cave, Bucks County, Pennsylvania. The bones are of the same character as those of Hartman's Cave.
Temperature of the Breath.—We have before noticed the fact that the effect of breathing upon the bulb of a thermometer through several folds of flannel is to raise the temperature of the thermometer several degrees above that of the mouth and body, and the theory suggested by Dr. Dudgeon to account for the phenomenon, that the breath is the vehicle by which superfluous heat is removed from the body. Dr. William Roberts pronounces this theory untenable, and indicates, as an experiment that will show it to be fallacious, that a naked thermometer placed in the mouth, and breathed upon by expiration, will hardly rise to the normal temperature of that part of the body. He suggests another explanation, which has been accepted by Dr. Dudgeon. It is, that the temperature of the thermometer is raised by the action of the specific heat which is liberated by the condensation of the moisture of the breath. If the experiment of breathing is repeated with the same thermometer and flannel at short intervals, the degree to which the temperature rises decreases with each repetition till at last only a slight effect is produced. This is because the flannel, already charged with moisture, has a diminished capacity for condensing more moisture with every new trial of the experiment. If, on the other hand, the flannel is thoroughly dried before beginning the experiment, an increase of temperature to 115°, or several degrees higher than the highest noted by Dr. Dudgeon, is indicated immediately on breathing upon it. The capacity of the cloth for absorbing moisture has been largely increased by the drying.
Perforation of Lead Pipes by Rats.—We give herewith another well-authenticated case of the perforation of a lead water-pipe by rats, kindly furnished by Mr. Henry C. Hallowell, of Sandy Spring, Maryland. Mr. Hallowell writes: "As the confirmation of a statement is sometimes of value, I send a hasty sketch of a piece of lead pipe in my collection that has been gnawed by rats, as described by Dr. William Eassie, in "The Popular Science Monthly" for January. The pipe is one
Lead Pipe gnawed by Rats.
and one eighth inch in diameter, and the lead three sixteenths of an inch thick. The hole is three inches long, and appears to have been made to get to water."
The Manufacture of Indigo in Bengal.—Indigo is almost entirely obtained from leguminous plants of the genus Indigofera, of which two principal species are grown in India and America. The factories in Bengal are provided with filters, presses, a boiler, drying-grounds, reservoirs, and vats for fermentation. The plant is cut in the morning, and taken to the factory. In the evening it is loaded in the vats, tightly pressed down, and then submerged in water and exposed to a process of fermentation for from nine to fourteen hours. The progress of the fermentation is tested by drawing off a little of the liquid, when, if it is of a pale straw-color, the quantity of indigo will not be so great, but the quality will be better than when it is of a deep-yellow tinge. The liquid, when it is drawn off after fermentation, is always of a more or less deep-yellow color. It is allowed to remain for some little time, and is then, while still warm, beaten with long bamboos for two or three hours. It gradually becomes of a pale green color, and the indigo forms into small flakes. The mass is allowed to remain for half an hour, and the water is then turned off gradually by withdrawing one by one corks which have been placed at different levels in the vat. The water is returned to the river, and the deposit, which resembles a thin scum, is carried through a trough into a deep trench. It is then brought up and boiled for a short time to prevent a second fermentation, which would turn it black and spoil it. After about twenty hours, it is again boiled for three or four hours; then poured off, and strained through a filter. A thick, deep-blue paste, almost black, remains on the cloth of the filter after the liquid has been strained through. This paste is exposed to a pressure, which removes every particle of moisture, after which the indigo is found in a large, thick block, the cutting of which demands extreme care. The blocks are put in the drying-ground, a large brick building from which the light of the sun is carefully excluded, and, after from three to four days, are ready to be sent to the market.
Purification of River-Water by Organic Agents.—Mr. R. Warrington, in "The Chemical News," notices that, in the discussions on the qualities of river-water, the destruction of sewage which takes place in such water is in every case referred to the oxidizing influence of the air, and the action of organic agents is overlooked. Yet it is evident, and generally admitted, that these agents play an important part in the change of organic into inorganic matter. The process is in effect the joint work of a number of independent organisms having different functions, the action of one class following that of another, and each carrying the process through a particular stage. First are the fungi, whose main function is apparently the rapid oxidation of carbon; then come the bacteria, embracing many families of similar physical structure, but endowed with very different chemical powers. One class attacks nitrogenous organic matter and liberates nitrogen in the form of ammonia; another determines the conversion of carbonaceous organic matter into inorganic carbonic and nitric acids. Lastly come the chlorophyl-bearing plants to consume these products of the lower organisms; they also have the property of assimilating urea and inorganic ash constituents. These organisms must follow in their order, or they will fail to do their work. Sewage will finally be destroyed in a river of adequate temperature, unless the natural agents of oxidation are excluded by the addition to the water of chemical refuse fatal to organic life, or unless vegetation is prevented by artificial means. Temperature and light, or rather darkness, are important factors in the process. The experiments show that the oxidation in rivers increases as the temperature rises. The amount of dissolved matter in rivers is found to be greatest in February, when organic action is suspended, and least in September and August, when the action is most energetic.
Mind in Work.—It is set forth on the highest authority that whatever we do should be done with our might. This precept being interpreted means that there should be mind in work. The difference between a work of art and the product of machinery lies in the presence of a mark of mind directing the handiwork in the one case, while the other is simply a predetermined result produced by a duly formulated process wherein or whereby physical forces are directed and controlled by other physical forces on a sot plan, to perform a defined series of actions, which must, in the nature of things, end in the production of the effect foreseen. Mind sets the one process, or series of processes, in operation, and they work out their physical destinies. In the other, mind is the active controlling power throughout. Starting from these premises, we are now concerned to point out that little or no success can be expected in any calling which does not suit the temper and bias of the mind pursuing it. There can not be "might" or earnestness—of the best sort—in an uncongenial enterprise. It is not necessary that an occupation should be ardently loved, but it is indispensable that there should be some special fitness for a calling if the powers of mind are to be resolutely and effectually engaged. Medical men see a great deal of life, and nothing strikes the observant family practitioner more than the number of feeble, sauntering, and loitering minds with which he is brought into contact. No inconsiderable proportion of the common and some of the special ailments by which the multitude are affected may be traced to the want of vigor in their way of living. The human organism is a piece of physico-mental machinery which can only be successfully worked at a fairly high pressure. It will almost inevitably get out of gear if the propelling force is allowed to fall below a moderately high standard of pressure or tension, and that degree of tension can not be maintained without so much interest as will secure that the mind of the worker shall be in his work. It is curious to observe the way in which particular temperaments and types of mental constitution are, so to say, gifted with special affinities, or predilections for particular classes of work. The men who work in hard material are men of iron will, which is equivalent to saying that the men of what is called hardheaded earnestness find a natural vent for their energy in work that requires and consumes active power. On the other hand, the worker in soft materials is commonly either theoretical or dreamy. There is a special type of mental constitution connected with almost every distinct branch of industry, at least with those branches which have existed long enough to exercise a sufficient amount of influence on successive generations of workers. We are all familiar with what are called the racial types of character. It would be well if some attention could be bestowed on the industrial types, both in relation to educational policy and the study of mental and physical habits in health and disease.—Lancet.
Changes on the Moon.—A European astronomer, M. Jules Klein, affirmed, in March, 1878, that he had discovered evidence contradicting the generally received opinion that all action had ceased upon the moon. He claimed that he had observed a large depression, in the shape of a crater, newly formed to the east of the crater Hyginus, and that a large valley had been made south of the mountain called by Mädler the Colimaçon. His views were disputed, and it was said that he had seen, not something that was really new, but something that had been overlooked in previous observations. He defends the accuracy of his affirmation in a recent number of the "Astronomische Nachrichten" by producing evidence that the objects he describes had never been noticed, until he pointed them out, by astronomers who had made a constant study of the moon, and whom they could not have escaped if they had not been new. The original journals of Gruithuisen, which have just been published, bear directly upon the question. They are accompanied by the astronomer's original designs, which are of an astonishing fineness and accuracy. Among the designs is one including the crater Hyginus, with its great cleft, and Mount Colimaçon. The most minute details are given; but the depression in Ilyginus is wholly absent, as is also the valley south of Colimaçon, although every other furrow on that side of the mountain, of which Gruithuisen made a special study, is scrupulously given. M. Klein describes his object as a large funnel-shaped crater, from which a shallow ladle shaped valley extends toward the south, terminating in a small crater. The valley may be recognized, when it is not in shadow, as a gray spot. M. Klein believes, but does not undertake to prove, that nebulous clouds are produced on the moon which have no analogies on the earth; and that whoever examines the observations which have been made on the lunar formations from the time of Gruithuisen to the present will be convinced that changes for which we can not account are taking place on its surface.
The Ocean-Currents of Greenland and Iceland.—Captain N. Hoffmeyer, Director of the Royal Danish Meteorological Institute at Copenhagen, has published a summary of the facts ascertained in the recent deep-sea explorations of the Danish schooner Fylla, Captain Jacobson, which help to explain, why Iceland, lying nearly on the edge of the Arctic Circle, is not frozen like its neighbor Greenland. The first Norwegian Deep-Sea Expedition, under Professor Mohn, brought out the surprising fact that the bank on which the British Islands lie is connected by a submarine ridge, of at most three hundred fathoms below the surface of the water, with the Faroe Islands, and that these islands are similarly connected with the southeast coast of Iceland; further, it was discovered that over this bottom ridge separating the Atlantic water in its great deeps from the water of the Arctic Sea—at least in summer—a relatively warm mass of water was moving toward the northeast which fully prevented the cold bottom water of the Arctic Ocean from flowing into the North Atlantic basin. Since, however, the depths of the Atlantic are occupied with a bed of water only a few degrees above the freezing-point, the cooling of which can not be ascribed to circumstances of place and position, but must be caused by an inflow of polar waters, the fact ascertained by the Norwegian expedition that no such inflow takes place between Iceland and Europe, in the broadest passage between the two seas, has become of the greatest scientific importance. Attention was accordingly directed to the other passages between the two seas—the Denmark Straits between Greenland and Iceland, and Davis's Straits—concerning the features of which not enough was accurately known. The most that had been learned concerning them was the work of a few observers, chiefly Admiral Irminger, who, by comparing the annual reports of voyages between Greenland and Iceland, had found that the Atlantic water along the fifty-ninth parallel, between the Orkney Islands and 30° west, over an extent of about nine hundred nautical miles, had tolerably uniform and relatively high temperature on the surface with a superficial current to the north; that, further, in consequence of this current, the warm surface-water, at least in summer, reached the south coast of Iceland essentially unchanged in temperature, and was directed thence toward the northwest and north into the Denmark Straits and along the west coast of Iceland; that, on the other hand, a cold stream filled with thick drift-ice flowed from the Polar Sea along the east coast of Greenland through the Denmark Straits to Cape Farewell, and was strong enough to reach over to the northwest coast of Iceland and fill its fiords with ice. As an offset to this, the ice does not, even in winter, enter the great bays of the west coast of Iceland, and the fisheries are prosecuted in those waters through the whole year. North of Iceland the stream sets decidedly toward the east, and often brings with it Greenland ice, which blockades the whole coast for a longer or shorter time. Admiral Irminger believes that this stream is a branch of the great East Greenland ice-stream which has rebounded from the northwest coast of Iceland and been deflected to the east. Other investigators have reached conclusions agreeing with these. In order to determine the matters which were in question, the Danish Government, in 1877, provided the Fylla with the necessary apparatus and ordered Captain Jacobson to take soundings and measurements of temperature. He performed his work with much energy, against many difficulties, and discovered that the warm stream which had been mentioned as washing the west coast of Iceland has considerable depth, and that it is strong enough at the North Cape to pass around it in its continued progress along the north coast of the island. The meteorological observations in the Island of Grimsey have also shown that this warm stream affects the island in the same way in the winter and considerably moderates its climate. Nevertheless, in severe winters, the Greenland ice pushes far down and causes the warm current to be covered with its cold meltings; the season is protracted, and Iceland suffers a bad year with hardly any summer.
Stammering.—Stammering, according to M. A. Chervin, generally originates in a sudden nervous shock which the victim of the affection has received in childhood; sometimes it is a habit which has been acquired by the practice of imitating other persons who stammer, or by constant association with stammering members of the family. It takes place whenever the rhythm of respiration is interrupted by the effort to speak being made at the wrong stage of breathing. Speaking, to be easy and regular, should be an act of expiration. Some persons begin to speak while they are drawing their breath, but are compelled to halt as soon as they have uttered the first syllables. They spit out their syllables; then, suffering an oppression of the chest, are compelled to relieve themselves from it, and the rest of the phrase goes out in a gasp. Others speak during the period of expiration, but do not begin until the lungs have been nearly emptied and have not air enough to keep up the action of their vocal organs. Others speak through their nose and fail in the utterance of the stronger consonants. Stammerers are not always equally liable to suffer from their affliction, but the intermittence is not regulated by any law. Sometimes they may be helped over the difficulty by pronouncing the embarrassing word for them; sometimes by a little diversion of attention. Children who stammer much are often able to speak with perfect freedom under circumstances in which they are free from embarrassment, as the stuttering boy playing with his dog, or the girl with her doll; but, if another interrupt them with the most simple question, they will begin to halt in their speech. The fault may often be alleviated or made to disappear by reading or speaking aloud when alone. Some persons are accustomed to use, before the syllables which give them difficulty, certain words which seem to them to smooth the way of the rebellious consonant. One stammerer is mentioned by M. Chervin who had the habit of saying et, mais, oui (and, but, yes), before every difficult word, whatever it might be, which often gave a ludicrous turn of expression to his remark. The same expedients do not, however, always have the same operation with different persons, and sometimes result oppositely with the same person. Singing is nearly uniform in its action. In chanted or rhythmic speech, as in the recitative of operas, stammering is very rare. Singing, reduced to its most simple element, cadence, enters largely into the application of the means employed by M. Chervin for the cure of the affliction. The poetic cadence in the declamation of verse and the variety of intonations which give to poetic diction a character very different from that of familiar conversation, are generally effective in preventing halting in the speech. More than this, it is often enough to speak or read in the same measure with a stammerer to make it more easy for him to speak or read. The accompaniment serves as a kind of support or guide, which affords incontestable assistance in a majority of cases. Generally, reading and recitation are easier than conversation, especially if they are carried on in a low voice. It is proper to remark, in connection with this point, that with all stammerers whose difficulty is accompanied with glottic spasms, articulation in a low tone, diminishing the play of the vocal chords, operates as a restraint upon one of the provocations to stuttering. There is no resemblance between stammering and what is called writer's cramp, which results from the excessive use of an organ; no connection between it and paralysis. When it occurs with paralysis, it is only as one of the symptoms. In the majority of cases it appears as a single infirmity in subjects otherwise healthy, is generally wholly curable, and may be ameliorated in the most rebellious cases.
Turquoises.—All the turquoises in Europe come from one mine, which is situated in Persia, on the road from Teheran to Herat, not far from Meschid, the capital of Khorassan. Two kinds of turquois are distinguished in mineralogy: the real stone turquois, or calaite (in Persian, sengui), and the osseous turquois or odontolite. The latter is considered a false turquois, and is supposed to be composed of a piece of bone colored with phosphate of iron. The Persians again divide the real turquoises into two kinds—the sengui, or stony, and the khaki, or earthy, turquois—accordingly as they are incrusted with the rock, or are obtained by washing the earth, and are clear of foreign matters. The mines are at the village of Maden, in the region of the salt-mines of Doulet Aly. The salt district is like an immense block of salt just covered with a thin soil of red clay. The miners get out the salt by making a hole, putting a ball of clay into it, and striking upon the clay till a block is detached. The hills in which the turquoises are found have the same reddish gray aspect as is remarked in the salt-rocks; they are formed of rocks and an earth full of pebbles, and are bored in their whole extent with galleries, tunnels, abandoned pits, and land-slides, which give the place a curious aspect. The mines belong to the Government, as do also the salt-mines, and are farmed out for a small sum. They are not very actively worked, and the product is small. The process for extracting the gems is much like that pursued in mining for the sale, except that, instead of using a ball of clay, the miners burn a bunch of dry grass in the hole, taking precaution, as soon as the cracks appear, not to damage the turquoises which may be incased in the block. The stones are generally found in groups, often numbering twenty-five or thirty, incrusted with a thin calcareous envelope which is white next to the mineral, brown on the side next to the rock. The khaki, or earthy turquoises, are found in the valley adjoining the hills, in a soil composed of gravel and rounded stones resting on a clay subsoil. After the earth has passed through two or three washings, a considerable number of turquoises are left, of moderate size, but pale and of little value, if the diggings are fresh. The turquoises in the older pits have a better color, because, the miners say, the stones acquire their color with age. Among the largest turquoises which have been mentioned are one of which a drinking-cup was made for the Shah of Persia, and one in which the treasure of Venice was kept, and which weighed several pounds. Generally the large turquoises are pale or discolored, and of little value, and are used principally for the decoration of furniture, and of the saddles and bridles of rich Persians.
Heat in Tunnel-Excavations.—Dr. F. M. Stapff, engineering geologist of the St. Gothard Tunnel, has published, in the "Revue Universelle des Mines," the results of the studies he made during the progress of the operations in the tunnel as to the highest temperature at which men can work underground, and the depth below the surface at which that temperature is likely to be met in tunneling. The limit of temperature at which men can work depends upon the length of their exposure, the amount of exertion they put forth, their condition, and the nature of the atmosphere, particularly as to its degree of moisture. It is certain that men can not become used to stand, for any length of time, a higher degree of temperature than from 140° to 165° Fahr., even when they keep perfectly still, and are in quite pure air. Men have worked at 104° on railways in the United States and Mexico, at 72° to 94° in Belgian collieries, at 125°, under exceptionally favorable conditions, in the Fahlun copper-mine in Sweden, and are said to work occasionally in the stoke-holes of tropical steamers at 156°. The highest temperature observed in the Mont Cenis Tunnel was 86°. In the St. Gothard Tunnel work was carried on at 87° on the Airolo side, in an atmosphere saturated with moisture, and at 84° on the Göschenen side, in an atmosphere less highly impregnated. Professor Du Bois-Reymond estimates that men can stand a temperature of 122° when the air is as dry as possible, but that even 104° is likely to be fatal in an atmosphere saturated with moisture; and he recommends quick lime, notwithstanding the heat it gives off, as preferable for counteracting the heat, because it absorbs the moisture, to ice, which adds to it. Salt and ice are, however, good. The highest limit of air-temperature theoretically possible in tunnel-work would be that which would induce fever-heat, or 107° in the body; the highest practicable, but still a dangerous, temperature should not raise the heat of the body over 104°. On this basis an extreme temperature of 114° would be admissible at the Göschenen end, and of 100° at the Airolo end, of the St. Gothard Tunnel. The temperature within the borings of the St. Gothard Tunnel was found to increase with the depth of the excavation, at a general average rate of 1° Fahr. per 88·1 feet of vertical depth below the surface of the mountain. The rate is subject to local variations, giving sometimes as much as 9° of error, arising from irregularities in the surface of the mountain. Thus the actual temperature is higher than the calculated temperature under depressions of the surface, and lower under peaks; but for considerable lengths of tunnel the calculated and actual temperatures substantially agree. Dr. Stapff estimated, when the excavations at St. Gothard had been driven to within about one thousand yards of the middle of the tunnel, that the temperature at the middle, before piercing the wall between the two excavations, would be 89° for the rock, and the same for the air about one hundred and fifty yards behind either fore-breast. The actual temperatures in March, 1880, after the two excavations had been connected, were 87°. The temperature of the air immediately at the two fore-breasts was brought down to 82° Fahr., while boring, and to 86° Fahr. while clearing away the débris, or to about 5° below the calculated point, by the operation of an extra supply of compressed air. The question of cooling the air in the tunnel-galleries presents great difficulties, for the heat of the rocks is inexhaustible, and the air, no matter in what condition it may be delivered, becomes heated up again nearly as soon as it is distributed. The use of jets of water is objectionable on account of the increase of dampness that attends it, and the mists to which it gives rise. Dr. Stapff is not able to recommend any better cooling apparatus than a combination of the cooling mixture of ice and salt and quicklime.
Relation of Elevation and Exposure to Rainfall.—M. Th. Moureaux has drawn up a set of maps based upon the reports of the Central Meteorological Bureau of France, which show what was the distribution of rain over the country for each month of the year, and for the whole year, 1878. Except in February and September, which were dry, the year was a moist one; the rains were excessive, except in the Mediterranean littoral and some parts of the valley of the Saône. The amount of rain increased with the height of the locality. The map shows at the first glance that the low regions, the plains, correspond with the smallest falls. The minima were constant during the whole year; in constructing the monthly maps, the absolute minimum in each month was found to be on the littoral of the Mediterranean, and the relative minima were found to correspond to the large valleys, whatever might be their direction. The valley of the Loire below Orleans, and those of its affluents on the left bank, the basin of Paris, the valleys of the Garonne, of the Saône, of the Lower Rhône, were regions in which relatively little water fell. In mountainous regions, at the same height, the rains were much more abundant on the slope exposed to the direct action of moist winds than on the opposite slope. When a mass of air rose along the side of a mountain, it became steadily cooled, its load of moisture was relatively increased, and the clouds soon precipitated their burden; the condensation was more active as the difference of temperature increased, and as the air of the plain approached the point of saturation. The inverse phenomenon was produced on the opposite slope. Descending the side opposed to the direction of the wind, the air became warmer, and its temperature further and further from its dew-point; the rain was light and often there was none. The minima were thus constant during the several seasons. The same was not the case with the maxima. They could be divided into three groups: 1. Those maxima wholly due to altitude; 2. Those which were attributed to the combined influence of altitude and of the situation as related to moist winds; 3. Those which were connected with the action of neighborhood to the sea. In the first group, the rule was absolute; the highest points constantly received more rain than the surrounding places of a loss altitude. But this was not the case with the maxima which were due to the neighborhood of the sea or to exposure to rain-bearing winds. The maxima of the hills of Normandy, Brittany, and Poitou were due to the fact that those provinces lay near and to the east of a great mass of water. This influence was made effective by the frequency of winds from the west, which drove toward those regions the moist air of the ocean; accordingly, it was most clearly manifested during the cold season; but the maxima were considerably lessened, or disappeared when the rains came from the southeast. So the maximum of the gulf of Gascony resulted from the predominance of winds from the west or northwest; and, when the south winds were pouring torrential rains into the basin of the Rhône, but little water fell in the basin of the Adour. Heavy rains did not fall simultaneously over the whole of the central plateau. They were limited to the slopes exposed to the direct action of rain-bearing winds. When brought by winds from the south or southwest, as was most frequently the case, they fell upon the side toward the ocean; while, when they came from the south and southeast, they were deposited on the Mediterranean slope. The laws of the distribution of rains, which M. Belgrand announced in 1865 for the valley of the Seine, are verified by the maps, and their general application appears to be made more clear every year.
The Asteroids and Jupiter.—Dr. J. Holetschek has published, in the "Deutsche Rundschau," a summary of our present knowledge of the asteroids, or the group of bodies which revolve in orbits between those of Mars and Jupiter. Of the two hundred planets of this group which had been discovered in July, 1879, sixty-three were discovered in the United States, sixty in France, twenty-eight in Germany, seventeen in Austria, fifteen in Great Britain, eleven in Italy, five in Asia, and one in Denmark. Professor Peters, of the Clinton Observatory, has discovered more (thirty-six) than any other single observer. The orbits of one hundred and seventeen were calculated in Germany, those of forty-eight in the United States, and those of the others in Austria, France, England, Russia, and Sweden. The theory at first adopted that these bodies are the fragments resulting from the explosion of a larger planet, was contradicted by the calculations of Professor Newcomb, in 1860. D'Arrest sought to establish the fact of a connection among them by finding relations in the eccentricities of their orbits, but the elements of the planets discovered since have set this theory at rest. The idea of a collision of two bodies has also been given up. The little planets mock all attempts to combine their relations, and each asserts its individuality as an independent member of the solar system. They exhibit common features only in the limitation of their orbits, so far as the discovery of them has extended, to a particular zone, and in a corresponding limitation of their periods of revolution around the sun. Taking the earth's mean distance from the sun as unity, the halves of the major axes of their orbits may all be represented by numbers between two and four. Their periods of revolution around the sun are between four and eight times that of the earth. Great variations occur within these limits. Very perceptible and peculiar intervals exist in several cases in the mean distances of particular asteroids from the sun, which might once have been accounted for by supposing that there were planets not yet discovered which would occupy them. But as the numerous discoveries of new planets have failed to furnish the bodies sought for, and have rather rendered the gaps more obvious, it has been suggested that the vacancies are not casual, but are owing to a real natural cause. A theory has been suggested that they are occasioned by the attraction of Jupiter, and is supported by the fact that a vacancy exists at every distance from the sun at which the time of a planetary revolution would bear a definite relation to the year of Jupiter. A planet could not continue in such a position, for it would be subjected to disturbances at every conjunction with Jupiter, the effect of which would be to draw it out of its course and out of its relation with the larger planet till it found a new period of revolution not commensurable with that of Jupiter. A large gap exists between the asteroids Gerda and Sibylla, in the place which a planet making two revolutions to one of Jupiter would occupy. Gerda, having an orbit interior to this place, completes its revolutions in fifty-four days less; Sibylla, with an exterior orbit, requires a period one hundred and two days longer than that of half the year of Jupiter. Similar gaps exist at distances where planets, if there were any there, would have periods of revolution corresponding to two thirds, two fifths, three fifths, two sevenths, and three sevenths of that of Jupiter, although planets are found on either side of these spaces whose periods of revolution bear no fractional relation, or an extremely remote one, to that of Jupiter. Saturn also produces modifications in the position of the asteroids which are less noticeable on account of its greater distance and lighter mass.
The Diffusion and Softening of the Electric Light.—M. L. Clémandot, a French engineer, has invented a new arrangement for the diffusion of the electric light, which, he claims, presents considerable advantages over the opaque globes hitherto employed for that purpose. The globes operate by absorbing the light until they become luminous—a process in which a considerable proportion of the light is wasted. M. Clémandot aims by his process to make all the light available for illumination. It is based on the principle which governs the diffusion of the light of the sun. This is effected by vapors floating between us and the sun, which distribute the light equally without stopping more than a very small proportion of it. To imitate these vapors he uses a solid substance, but in a condition so attenuated as to be, for practical purposes, almost the same as vaporous. It is glass, spun into threads one hundred and seventy-five times finer than a hair, or forty-five times finer than the finest silk fiber, with which he surrounds the light with a double envelope. His glass-fleeces are put into a lantern constructed especially for the purpose, so as to exclude dust, the glasses of which may be given any desired degree of opacity, and any color, including those colors which will neutralize the injurious properties of the electric light. The apparatus can be adapted to any of the systems of electrical lighting.
William Lassell.—William Lassell, LL. D., F. R. S., the famous astronomer and maker of telescopes, died October 5th, in the eighty-second year of his age. His name is closely associated with the history of the reflecting telescope. About 1820, not having sufficient means to enable him to buy expensive instruments, he began to construct reflecting telescopes for himself, beginning with a Newtonian and a Gregorian telescope of seven-inch aperture, with which he succeeded so well that he was encouraged to make a Newtonian instrument of nine inch aperture. In 1844 he began an instrument of two feet aperture and twenty feet focal length, in the making of which he introduced many improvements over the similar instrument of the Earl of Rosse. With this instrument he discovered the satellite of Neptune in 1846, the eighth satellite of Saturn, simultaneously with Professor Bond, in the United States, in 1848, and two satellites in addition to the two already known, of Uranus, in 1851. He afterward made an instrument of four-feet aperture and thirty-seven feet focus, which he set up at Malta, and with which he made numerous observations of nebulae and planets, besides preparing a catalogue of six hundred new nebulæ discovered at Malta. His latest recorded work was the construction of an improved form of machine for polishing large telescopic mirrors, which is described in the "Transactions of the Royal Society" for 1874.
Climatology of Europe.—The climate of Western Europe is ameliorated by the warmth of the Gulf Stream in winter, and by the neighborhood of the ocean in summer, and approaches what is called an insular climate. In Eastern Europe these modifying influences cease to be felt, and the climate gradually assumes a continental character, with greater differences of temperature, colder winters and warmer summers. The differences in the summer temperatures of the eastern and western regions are less marked than those in the winter temperatures, and amount at most to about 27°. For the greater part of the continent the difference in the temperature of July is not more than about 18°. The mildest summers are felt in Ireland and Norway, and the hottest in Southeastern Europe. The difference is perceptible between places in corresponding latitudes in the southeast and southwest. Thus, Syracuse is 7° and Sebastopol is 512° warmer in July than Lisbon and Oporto. A similar difference, but less in extent, appears in going eastward along the northern parallels. The differences in the winter temperatures of the several parts of the continent are much more marked than are those of the summer temperatures. The mildest winters are felt along the Mediterranean coast and in the Iberian Peninsula, where the mean temperature in January is from 16° to 19°. The next mildest are those of the western coast of France and the southern coast of England and Ireland. The winters of western Scotland and the Orkney and Faroe Islands are milder than those of Berlin and Milan; those of the Arctic coasts of Scandinavia than those of the Gulf of Bothnia, as is shown by the fact that the Arctic fiords of Norway, even as far as North Cape, are not frozen, while the Gulf of Bothnia is regularly frozen in winter. In Russia the January temperature diminishes as we go east, so that, while it is about 24° at Warsaw, it is reduced to 4° at Uralsk. The highest annual mean temperature, the mildest winters and the warmest summers, must be looked for where the land approaches the thirty-fifth parallel, at the southern points of Spain, Sicily, and Crete. The highest known mean in Europe is at Catania, 65°, the temperature of January being there 51°, and that of August 81°. Gibraltar enjoys a warmer temperature in January, 54°, nearly corresponding with the temperature of Cairo. The January of Catania is like that of the end of April, the January of Gibraltar like that of the first half of May, in Berlin. These extreme southern points suffer, however, occasionally from frost and snow. Snow fell on the African coast in 1845 and 1850, and in the latter year a temperature below the freezing-point was observed as far south as the Sahara; and the Nile is said to have been frozen in the year 859. So it is safe to assume that no place in Europe is secure from snow and frost.
A New Theory of Chemical Affinity.—M. Berthelot has endeavored, in his recently published "Essai de Mécanique Chimique fondée sur la Thermochimie," to connect the laws of chemistry and the theory of the unity of physical forces. He believes that he has discovered a direct relation between chemical affinity and the capacity of different bodies in combining to throw off heat. Thus hydrogen burns in oxygen, liberating enormous quantities of heat; the affinity of the two bodies is known to be strong. The same is the case with phosphorus and oxygen. But nitrogen and hydrogen, instead of liberating heat when they combine, absorb it. Their affinity for each other is feeble. Again, when two bodies combine in different proportions, forming different compounds, it is always the combination in which the most heat is liberated that tends to form. More heat is liberated in the formation of water than of the binoxide of hydrogen, and it is water that is naturally formed when the bodies burn together. This law of chemical compositions and decompositions has been termed by M. Berthelot the principle of maximum work, and is enunciated by him thus: Every chemical change accomplished without intervention of a foreign energy (heat, electricity, light) tends to the production of the body or system of bodies which liberates heat. This principle throws light on a multitude of facts hitherto unexplained. M. Berthelot indicates many applications of his principle. Acetic acid, combining with soda, produces a certain amount of heat, and forms acetate of soda; hydrochloric acid, combining with soda, liberates more heat, and forms chloride of sodium. If, now, we apply hydrochloric acid to the acetate of soda, chloride of sodium will be formed, with the production of an amount of heat just equal to the difference between the heat of formation of acetate of soda and that of chloride of sodium; but the converse will not take place when acetic acid is mixed with chloride of sodium. Combinations which are formed with much liberation of heat are very stable; those in which heat is not liberated are unstable. Chloride of sodium will resist a white heat without decomposing, while chloride of nitrogen, in the formation of which heat is absorbed, will decompose and explode spontaneously. This fact leads to another remark: that, in accordance with the law of maximum work, all explosive bodies are bodies that produce heat in being decomposed.
Diseases of Miners.—Dr. Paul Fabre, of Commentry, France, has made a particular study of the diseases of miners. He has found that diseases, the character of which is largely governed by certain accessory circumstances, are prevalent among workmen who labor in damp or wet galleries. No morbid symptom is developed among those who work in a gallery which is simply damp and of a temperature of not more than 58°. But if cold water falls upon them, or if they have to put their legs in water, they become subject to lumbago, sciatica, to indefinite pains in their limbs, and often to a real rheumatism. The rheumatism is generally subacute, sometimes chronic, and most often localized in a single joint—generally that of the left knee, on which the pick-men and heavers rest in working. In galleries which are saturated with moisture and where the temperature exceeds 77° to 86°, the workmen are soon overcome with an extreme lassitude; they get hot, they gasp for breath, the sweat rolls down their bodies, and they are obliged to stop working and rest for a while in a cooler spot, A rapid enervation which compels frequent changes of the men in the gallery, sudoral or miliary eruptions, sometimes boils, rarely eczema, are among the phenomena which Dr. Fabre has most frequently observed in these conditions. If, while the gallery is constantly damp, the air is vitiated by poisonous or irrespirable gases, and if the water contains sulphates or sulphuric acid in solution, the men, in addition to pains in their limbs and difficulties in breathing, experience lively itchings and painful smarts wherever the surface of the skin has been abraded. Those who have labored for a long time in the damp galleries contract a chronic inflammation of the gums, together with muscular pains in the limbs, and have often intestinal troubles and spots of purpura. These phenomena indicate the coming on of a mild form of scurvy. The remedies are to be found in whatever will improve the sanitary conditions of the mines and the homes of the miners, and in the usual applications for scurvy whenever the symptoms of that disease appear.
Variability of the Level of the Ocean.—M. H. Trautschald, of Moscow, lately sent in a paper to the Geological Society of France, maintaining that the level of the ocean was not invariable, in which he expressed the following conclusions: 1. The level of the sea has fallen, as parts of the earth's crust have risen from the bottom above its surface; 2. The surface of nearly all the continents has once been at the bottom of the sea, and has risen from the waters, partly in consequence of upheavals, partly in consequence of the retreat of the ocean; 3. When the continents have been formed, a part of the waters of the seas is carried away from them, and held on the land as lakes, rivers, eternal snows, and as a constituent of organic matter—thus the quantity of water in the ocean has been constantly diminished, and its level has fallen; 4. As the earth cools, ice accumulates near the poles and on the mountains, water is soaked down more deeply into the crust of the earth, and mineral hydrates are formed everywhere. It follows that the level of the sea has been gradually falling ever since water has existed as a liquid upon the earth.
Spiders and Tuning-Forks.—According to observations recorded by Mr. C. V. Boys, in "Nature," spiders are very sensibly affected by the vibrations of a tuning-fork, and act toward it as they would toward a fly that comes to their web. When a fork, lightly touching a leaf, or other support to the web, was sounded, the spider, if at the center of the web, would lace the fork and feel with its fore-feet to find along which radial thread the vibration was traveling. Having become satisfied on this point, it would run along the proper thread till it reached the fork, or, if it came to the junction of two threads, would first stop and determine which was the right one. If the spider was not at the center of the web, and was not on a thread in contact with the fork, it had, when it perceived a vibration, to go to the center to see which radial thread was vibrating. It would then run out to the fork. If the fork was not removed when the spider had reached it, it would seize it, embrace it, and run along on the legs of the fork as often as it was made to sound, "never seeming to learn by experience that other things may buzz besides its natural food." If, when a spider had been enticed to the edge of the web, the fork was withdrawn, and then gradually brought near, the spider seemed aware of its presence and direction, and would reach out after it; but, if a sounding-fork was gradually brought near a spider that had not been disturbed, the spider would instantly drop; then, as soon as the fork was made to touch any part of the web, it would climb back and reach the fork with marvelous rapidity. By means of a tuning-fork a spider could be made to eat what it would otherwise avoid—even a fly dipped in paraffine—if its attention was kept fixed by the constant vibration of the fork.
Deterioration of Binding in Libraries.—Mr. H. A. Homes, in the "Library Journal," notices some causes additional to those arising from the use of gaslights, which may conduce to the deterioration of bindings in libraries. The modern methods of tanning do not give as durable a leather as the old processes, which it took months or years to complete. This may be the reason that the goat-skins of Turkey, in the tanning of which there is nothing modern or "improved," are still recognized as furnishing the best leather for bindings. The sulphide of sodium that is sometimes used in tanning may supply a part of the sulphur that is complained of in modern libraries. A second cause is the practice of using split skins, which gives a binding only half as strong and lasting as the old whole skins; and a third cause may be found in the gases escaping from the hot-air furnaces with which libraries are warmed, which are hardly less destructive than the products of illumination, and are more constantly in action.
Mixed Education.—Professor Alexander Hogg, in a note reprinted from the "Proceedings of the National Educational Association," refers to the perplexities arising from mixing military with industrial education in the Agricultural and Mechanical College of Texas. A cadet failed to receive promotion at the hands of the faculty, and the board of directors confirmed their decision, and then turned out the whole faculty. Professor Hogg says that serious troubles have befallen these institutions in several States, and remarks: "With regard to the cause, I venture to suggest that it will be found that it has all grown out of the complications of attempting to run in the same institution these three leading features, viz., agricultural, mechanical, and military education. The military, so far as I have been able to learn (and this is corroborated by my personal experience), is the source of all the troubles. And this, I think, grows out of the further fact that the military, to be of any use whatever, must be thoroughly equipped in all its departments and requirements, while the act of Congress, granting lands for the support of these colleges, intended it should be secondary, and cultivated entirely as a means of discipline and good order—not at all intended to make proficients in arms, but simply as a gymnastic exercise."
Rate of Growth of Coral.—Light is thrown on the question of the rapidity with which corals grow, by the case of specimens of living coral which were recently found on the hull of the French man-of-war Dayot, after a cruise of a few months in the South Pacific Ocean. When the vessel reached Tahiti, several corals were discovered growing on the copper sheathing, the longest of which was fungia of discoidal shape nine inches in diameter, and weighing when half dry two pounds and four ounces. The Dayot had entered tropical waters several months before, but had not made a long stay in any harbor until she reached the Gambier Islands, where she remained for two months in the still waters of a coral basin. Thence she sailed direct for Tahiti. A young fungia probably became attached to the sheathing of the ship in passing the reef, where the vessel rubbed, and grew to the size and weight it had attained when observed, in nine weeks.