Popular Science Monthly/Volume 38/February 1891/Popular Miscellany

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Popular Science Monthly Volume 38 February 1891  (1891) 
Popular Miscellany
 

POPULAR MISCELLANY.

Pasteur Institute, New York. — From the opening of the New York Pasteur Institute, February 18, 1890, till October 15th, 610 persons that had been bitten by dogs or cats presented themselves to be treated. For 480 of these patients it was demonstrated that the animals which attacked them were not mad. Consequently, they were sent back, after having had their wounds attended during the proper length of time when it was necessary; 400 patients of this series were consulted or treated gratis. In 130 cases the antihydrophobic treatment was applied, hydrophobia having been demonstrated by veterinary examination of the animals which inflicted bites, or by the inoculation in the laboratory, and in many cases by the death of some other persons or animals bitten by the same dogs. All these persons were, on the day of the report, enjoying good health. In eighty cases the patients received the treatment free of charge. The persons treated were — sixty-four from New York; twelve from New Jersey; twelve from Massachusetts; eight from Connecticut; nine from Illinois; three from Missouri; three from North Carolina; three from Pennsylvania; two from New Hampshire; two from Georgia; two from Texas; one from Maryland; one from Maine; one from Kentucky; one from Ohio; one from Arizona; one from Iowa; one from Nebraska; one from Arkansas; one from Louisiana; and one from Ontario, Canada.


The Tuscarora Deep. — Rear-Admiral Belknap, of the United States Navy, read a paper before the Asiatic Society of Japan in Yokohama, in October, describing the deep soundings made by his survey vessel, the Tuscarora, in the Euro Siwo, last summer, and comparing them with deep soundings in other seas and parts of the ocean. The main object of the Tuscarora expedition was to determine the feasibility of a cable route across the mid-North-Pacific from California to Yokohoma, by way of Honolulu and the Bonin Islands, and on the homeward run to survey a second route from a point on the east coast of Japan, on a great circle running through the Aleutian chain of islands, and ending at Cape Flattery at the entrance of Puget Sound. The mid-Pacific survey had been successfully run, without finding any unusually remarkable depths, and the party anticipated that the return survey would be correspondingly easy. But, putting to sea on the 10th of June, the Tuscarora had hardly got a hundred miles from the coast, when a sounding was made of 3,427 fathoms, the waters having deepened more than 1,800 fathoms in a run of thirty miles. The next cast was still more startling, for, when 4,643 fathoms of wire had run out, it broke without bottom having been reached. Corresponding depths to these were found in all the soundings taken in that neighborhood, the greatest measured being 4,655 fathoms. At 4,340 fathoms a Miller Casella thermometer came up wrecked from the resultant pressure. The time occupied in making a cast of 4,356 fathoms and getting back a specimen of the bottom was two hours twenty-six minutes and fifty-seven seconds. Good specimens were brought up from four of the depths, and in one other the specimen-cup struck rock. At the deepest of the casts the wire parted. In view of the remarkable depths found, the conclusion was irresisti- ble that the great-circle route would have to be abandoned, and a new line of less depth adopted if it could be found. This series of depths, ranging from 3,500 fathoms to 4,600 fathoms and upward south and east of the ridge between Cape Lopatka and the Aleutian Islands, indicates that a trough or basin of extraordinary depth and extent exists along the east coast of Japan and the Kurile Islands and under the Black Stream (Kuro Siwo), exceeding any similar depres- sion yet found in any other region of the great oceans. The depth of the deepest cast five miles and a quarter, the deepest wa- ter yet found is sufficient to hold two mountains as high as Japan's great Fusi- jama, and leave them nearly two thirds of a mile under water. This region of the Pa- cific has been named by the German geog- rapher Petermann the " Tuscarora Deep."

Improvement of Printing-machines.

The first automatic printing-machines, ac- cording to Messrs. Southward and Wilson's woik on the subject, were invented for calico-printing in 1*750. About a hundred years ago, Nicholson took out a patent for a machine applicable to the printing-press. It did not come into use, on account of Nicholson's poverty, and the first practical machine was made by Koenig in 1810, when the Annual Register was printed on his press. This machine was capable of printing a thousand copies in an hour, while no other press then existing could print more than a fourth of that number. Curved stereotype plates were made by Cowper in 1816. Inking by rollers had al- ready been invented. For the last sixty years progress has been very rapid, and every year brings some new machine to

��save time and trouble, and increase the speed of production. Much attention is now given to type-setting machines, of which six are described by Southward and Wilson as in use. The great difficulty in the use of these machines, which has only now been solved, is in the distribution of the type. It is evaded in the London Times office by taking a cast of the matter, then melting the type and refounding it. One of the latest machines, it is said, however, ef- fects the distribution as rapidly as the set- ting.

The Aye-aye. A curious creature is the aye-aye (Cheiromys madagascariensis), which was long a puzzle to naturalists on account of its many peculiarities of form and structure. It was named by the French traveler Sonnerat, after an exclamation made by the Malagasy natives on seeing it. It is classified by Prof. Owen as the sole representative of the last of the three fami- lies into which the lemuroids are divided. It has eighteen teeth, of which the four front ones two upper and two lower are much like those of a rat. Cuvier compared the lower teeth to plowshares. They are powerful cutting instruments, and availa- ble for removing wood, making holes in branches, and gnawing through the stems of sugar-canes and other similar plants. The ears are large, round, and open, and have been compared to those of a bat ; the eyes are wide and staring ; and the upper lip is perfect, or uncleft. The whole body, ex- cept the ears, nose, soles, and palms, is cov- ered with thick, dark fur. The most curi- ous peculiarity of the animal lies in the structure of the third and fourth fingers, which are very long, the fourth being the largest and longest, while the third is so ex- traordinarily thin and wasted in appearance that, as Prof. Owen-says, it seems as if it was paralyze d. The use of this finger is described by Prof. Saudwith, who gave his pet aye-aye some sticks to gnaw which were bored by grubs : " Presently he came to one of the worm-eaten branches, which he began to ex- amine most attentively, and, bending forward his ears and applying his nose more closely to the bark, he rapidly tapped the surface with the curious second digit as a woodpecker taps a tree, though with much less noise, 568

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��from time to time inserting the end of the slender finger into the worm-holes as a sur- geon would a probe. At length he came to a part of the branch which evidently gave out an interesting sound, for he began to tear it with his strong teeth. He rapidly stripped off the bark, cut into the wood, and exposed the nest of a grub, which he daintily picked out of its bed with the slender tapping finger and conveyed the luscious morsel to his mouth." The aye- aye is nocturnal, and seldom lets itself be seen in the daytime.

Montezuma's Head-dress. A study was recently published by Mrs. Zelia Nuttall of a rare object in the Imperial Ambras Col- lection at Vienna which has been variously described as a Mex can head-dress, a gar- ment intended to be worn about the waist as an apron, and a standard. Whatever it may have been, it was supposed to have be- longed to some person attached to the court of Montezuma. The author decides that it was a head-dress. As it is now mounted, on a backing of black velvet, it presents a gorgeous appearance. The long, loose fringe of quetzal-feathers exhibits slight evidence of decay, while the other parts have been carefully restored. The fan-shaped base of the feather-piece is com- posed of harmoniously disposed concentric bands of delicate feather-work studded with thin beaten gold plates of different shapes. The details of the structure and attachment of these plates confirm what the early Span- iards said about the admirable nicety of Mexican industrial art. The loose fringe was composed of about five hundred of the long tail-feathers, of which each male quet- zal bird has but two. Next to it the most striking feature of the specimen is the broad turquoise-blue band of feathers on which a design was executed with small gold pieces, originally fourteen hundred in number, disposed, overlapping one another like fish-scales, so as to form a flexible rec- tilinear pattern suggesting a series of small towers. The blue of this band was edged with a band of scarlet feathers, so disposed that their inner sides, curling outward, formed a projecting ruffled border. Above this were fringes of the small wing-feathers of the quetzal and of the tail-feathers of the

��cuckoo, whose white tips formed a sharply defined broad line studded with small gold disks. The whole was skillfully worked upon a suitable backing, and secured by a kind of kite-frame. " Manufactured with the utmost care," says Mrs. Nuttall, "of materials most highly esteemed by the Mexicans, uniting the attribute and em- blematic color of Huitzilopochotli, fashioned in a shape exclusively used by the hero- god's living representatives, the high priest and the war chief, this head-dress could have been appropriately owned and dis- posed of by Montezuma alone at the time of the conquest, from which period it assuredly dates." It was probably one of the gifts sent to the Emperor Charles V by Cortes in 1519.

Influenza and the Weather. A study of the relations of weather and influenza, so far as they may be illustrated by the regis- trar-general's reports for London from 1875 to 1890, has been published by Sir Arthur Mitchell and Dr. Buchan. The recurrence of a strongly marked winter maximum and an equally marked summer minimum through the whole forty-five years, with a small sec- ondary maximum running from the middle of March to the middle of April, indicate that the rate of deaths from influenza is in- verse to the temperature. The curve show- ing their distribution is congruent with that for diseases of the breathing organs, with the addition of a slight rise in the spring. But although the epidemics occurred mostly during the cold season, they were not con- nected with any exceptionally cold weather at that season, but rather with exceptionally warm weather, which manifested itself gen- erally both before and during the epidemic. In no case was any exceptionally cold weather, intercalated in the period of the epidemic, accompanied with an increase of deaths from influenza, or even with an ar- resting of the downward course of the curve of mortality, if the cold occurred at the time the epidemic was on the wane. Other dis- eases which appear to have prevailed most extensively during epidemics of influenza are diseases of the breathing organs, phthisis, diseases of the circulatory system, rheuma- tism, and diseases of the nervous system. The diseases which yielded a mortality un-

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��der the average during the prevalence of the epidemic were diarrhoea and dysentery, liver disease, measles, scarlet fever, typhoid fever, and erysipelas. The death-rate of persons above twenty years old rose consid- erably above the average during the four or five weeks immediately preceding the begin- ning of the registration of deaths due to the epidemic. In studying the dissemination of germs of the disease by winds, it is well not to confine attention to surface winds. It ia now found that atmospheric circulation takes place largely through cyclones and anticyclones, by means of which the levels of the currents are changed.

Zigzag Lightning. It was asserted by Mr Shelford Bidwell, in a lecture at the Lon- don Institution, that the zigzag lightning- flash of artists has no existence in nature, but is simply an artistic fiction or symbol ; and the speaker produced photographs to prove his point, asserting that not an in- stance of the zigzag flash could be found among the two hundred specimens in the collection of the Meteorological Society. Mr. Eric S. Bruce has since published a paper for the purpose of showing how the zigzag flash, which is really often seen by observ- ers and is frequently depicted by artists, may have a counterpart in nature consistent with the evidence of the society's photo- graphs. In his view, the appearance is not the flash itself, but is the optically project- ed image of the flash formed on clouds, not of a smooth surface, but of the rocky cumu- lus type. The image of the flash takes the angles of the uneven surface and becomes zigzagged. The author has exemplified this process by casting the photograph of a light- ning-flash, by means of the optical lantern, on model cumulus clouds, when the " stream- ing " flash became zigzagged.

Identification by Measure. M. Jacques Bertillon has described a method now prac- ticed in France of identifying criminals by comparing their measures. Photography is used in it only as an aid to identification es- tablished by other means. The basis of the system is to obtain measurements of those bony parts of the body which undergo little or no change after maturity, and can be measured with extreme accuracy to within

��a very minute figure. Those parts are the head, foot, middle finger, and parts of them, and the extended forearm from the elbow. By the classification of these anthropometri- cal coefficients, a list including any number of persons of whom photographs are obtained can be divided into many groups containing a small number of individuals each. Stress is laid on the importance of the hand and the ear as marks of recognition. The hand, because it is the organ in most constant use in every calling, and in many trades and professions it becomes modified in ac- cordance with the particular character of the work which it has to do. The ear is the precise opposite to this. It changes very slightly, if at all, except perhaps in the case of prize-fighters, who develop a peculiarity which is easily recognized. It is, therefore, an important organ to measure, inasmuch as the results are not likely to be nullified by a change in the conformation.

Irish Myths. In his book on the Myths and Folk-lore of Ireland Mr. Jeremiah Curtin regards as insufficient the theories of Mr. Miiller and Mr. Spencer, who de- rive all mythology from a misconception of the meanings of words and a confusion of ideas, and refers its origin to a misconcep- tion of the causes of phenomena. " The personages of any given body of myths," he says, " are such manifestations of force in the world around them, or the result of such manifestations, as the ancient myth-makers observed." Mr. James Mooney remarks that the definiteness of detail characteristic of Irish stories contrasts strongly with what is found in other parts of Europe. In Hun- gary, for instance, the usual introduction is, " There was in the world " ; while the Rus- sian story-teller, hardly more satisfactory, informs us that " in a certain state in a cer- tain kingdom there was a man." In the Irish myths, on the contrary, according to Mr. Curtin, we are told who the characters are, what their condition of life is, and how they lived and acted ; the heroes and their fields of action are brought before us with as much definiteness as if they were per- sons of to-day or yesterday. The Gaelic my- thology, so far as it is preserved in Ireland, is said to be better preserved than the my- thology of any other European country.

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��From the definite character of the myths, together with the internal evidence afforded by the language itself, it would seem that the Gaelic occupancy of Ireland dates from a very remote antiquity going back, in fact, to the period of the earliest wave of migration from the primitive home of the Aryans.

Cariosities of African Custom. Yet new phases of African life and custom are de- scribed in the diary of a journey from Bihe to the Bakuba country of the eminent Port- uguese trader, Silva Porto. The Kiboko or Kashoko, when their chief dies, either re- turn to their relatives or build themselves a new village. The new chief also builds a new village, and receives a man or a woman from each of his sub-chiefs as a contribution toward peopling it. The lukatio, or brace- let, bestowed as a symbol of power upon one of the chiefs by his superior for faithful service, is made of brass or copper, inter- woven with the sinews of a human being who has been sacrificed on some specially solemn occasion. It is covered with the skin of an antelope, and has charms attached to it. If the holder of this emblem loses the favor of his feudal lord, a messenger, bearing a similar bracelet, but of smaller size, and a two-edged knife, is sent to him, and the disgraced chief and his brothers and wives usually with him quietly submits to decapitation. A curious custom, called slnkai/andando, is observed by the Bakuba in concluding a bargain. An offer having been made and accepted, the vender plucks a leaf and presents it to the intending pur- chaser, who taking hold of it cuts it asunder, when the two pieces are thrown behind. If this mode of confirming a bargain is neg- lected, the vender can claim double the value of the merchandise in question.

Preservation of Mummies. A supposi- tion that the mummies of the Egyptian kings in the Archaeological Museum at Gbizeh had begun to decay since they were unrolled and deprived of their bituminous coverings was suggested by the appearance of a white efflorescence on certain parts of the mummy of Seti I. In order to ascertain whether this was true, Dr. Fouquet, a person having special qualifications for the work.

��was invited by M. Grebaut to examine the mummies and the efflorescence, and deter- mine whether signs of decay had been de- veloped since the unrolling; whether the efflorescence was the result of damp, and whether the mummies were threatened with destruction. Dr. Fouquet reported that he had observed the efflorescence on the mum- my of Seti I at the time it was unbandaged, June 16, 1886; that a specimen of it ex- amined microscopically was found to be composed of scales and prisms of crystallized salts, with the origin of which dampness had nothing to do, and that in it were neither mycites nor spores ; and that efforts to propagate mold on pieces of mummy and mummy-cloth exposed to damp resulted only in sterility. The efflorescence is, in fact, simply an extrusion of the salts employed in the embalming of the mummy, and of the repairs to the same when it was removed, about twenty-three hundred years ago, from its original resting-place to Dahr-el-Bahari. Hence, the mummies are supposed to be safe from atmospheric deterioration.

The Fijians. In a lecture on the Fiji Islands, delivered at Hokitika, New Zealand, the Rev. S. J. Gibson said that the native population was about a hundred thousand, while the Europeans numbered three hun- dred thousand. All the natives have em- braced Christianity ; churches and schools are found in every village, and crime is al- most unknown. In the construction of the native houses, chimneys and partitions are not appreciated. The sleeping-place is di- vided off by mosquito-curtains only. The men are powerful, well developed, with cop- per-colored skins, and some of the women are of prepossessing appearance. European clothing is used by some of the natives, and gives them occasionally a grotesque appear- ance. Oiling the body and liming the hair are customary. A dress consisting of a white shirt, a length of white sheeting round the waist, and a sash of native cloth is be- coming. Young girls wear a waist - cloth and a sort of pinafore, without either head- covering or boots. The language is musi- cal, but difficult to master ; and it is, indeed, almost impossible for a white man to learn it thoroughly. A kind of bread is made by burying fruit with some substance to make

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��it ferment. After a time it is dug up and eaten ; but the smell is rather strong at first. Fiji is a commonwealth in the proper sense of the term, all articles being public property. No native lives by trade, and they seem to have no idea of the principles of commerce. They are industrious, and adepts in pottery and wood-work, although their implements are for the most part crude. The native drum, formerly used to sound the war alarm, is now employed to summon people to church, which they all attend.

Ocean Transportation of Plant Species.

Experiments performed by Dr. Guppy at the Keeling Islands, which are six or seven hundred miles from the nearest large land, show that certain kinds of seeds will germi- nate freely after being thirty, forty, or fifty days in sea-water. During this time they may be conveyed, on a drift current of only one knot an hour, a distance of from one thousand to twelve hundred miles. Some seeds that do not readily float, or float only for short periods, are conveyed hither and thither in a variety of ways as in the cavi- ties of pumice-stone, and in the crevices of drift-wood. Such seeds as germinate have difficulties in establishing themselves, the most formidable of which are caused by the crabs, which eat the green sprouts as soon as they appear. If the plants escape the crabs in their earliest infancy, they are safe. An evidence of the tenacity of life under unfavorable conditions is afforded by the fact that despite clearing and cultivation, and the introduction of foreign enemies, no species of plant ever known to grow wild on the little islands has become quite extinct.

The Wise Use of Medals. More dis- crimination in awarding medals by learned societies is recommended by Prof. W. M. Williams. " Looking critically," he says, " at the awards that have been made during the present generation, it is difficult to find a case in which the honor has not been fairly earned ; but still, I think, they have not been as beneficially awarded as they might have been, nor in the manner generally desired by their founders. Most of them were in- tended as a stimulant, encouragement, and help to scientific workers. Such a medal

��would be all these to a poor or young or obscure worker, but is none of them to a man whose reputation is established, whose scientific eminence is already attained, and who is already quite sufficiently official." A case in point is that of J. A. R. Newlands, whose duly published discovery in 1864 and 1865 of the periodic law of the chemical elements was not noticed, while the Royal Society's Davy medal for the same discov- ery was given four or five years afterward to the "official" chemists Mendeleef and Lothar Meyer. But at length, in November last, Newlands received the medal which he had earned previous to either of the other chemists.

Leonardo da Vinci's Theory of Fossils.

M. Charles Revaisson is publishing photo- typic facsimiles of the manuscripts of Leo- nardo da Vinci. It seems that nothing which constituted the scientific domain of mankind in the sixteenth century was strange to that illustrious artist. We give here his theory of the formation of fossils : " Of animals which have bones on the outside, such as shell-fish, snails, and oysters, of innu- merable species. When the floods of turbid rivers discharge fine mud on the animals living in the adjoining waters of the sea- shore, the animals remain pressed in the mud, and, being overwhelmed by its weight, necessarily die for want of the creatures on which they are accustomed to feed. The sea receding in time, this mud, the salt water having run off from it, becomes changed into stone, and the shells are filled with sand instead of the animals that have de- cayed from within them. Thus, in the midst of the transformation of all the surrounding mud into stone, that also which remained within the shells becomes joined by means of a slight opening of the shells with the other mud ; so that all the shells are inclosed within the stone that is, the stone that in- cludes them and that which they contain. These shells are found in many places ; and nearly all the petrified mollusks in the rocks of the mountains still have their natural shells particularly those which had grown old enough to be preserved by their hard- ness ; and the young, being already for the most part reduced to lime, had been pene- trated by the viscous and petrifiable humor.

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��"Of the bones of fish which are found in the petrified fishes. All animals having bones within their skin which have been covered by the mud of rivers, which have overflowed their ordinary beds, have received to the line the impress of that mud. And with time, the beds of the rivers having fallen, these animals having the impression of the mud which has inclosed them and consumed their flesh and organs, the bones alone remaining their organization being consumed they have fallen to the bot- tom of the concavity of their impression ; and in that concavity the mud, when it has been dried by its elevation above the course of the river from its aqueous moisture and then from its viscous moisture, becomes stone, inclosing within itself whatever it finds there and filling everything hollow with itself. And finding the concavity of the impression of such animals, it pene- trates subtilely into the minute porosities of the earth by which the air which was in them escapes that is, by the lateral parts, for it can not escape above, because that porosity is occupied by t'-ie humor that de- scends into the void ; and it can not flee be- low, because the humor already fallen has closed the porosity. There remain the lateral particles opened so that the air condensed and pressed by the humor that descends escapes with the same slowness with which the humor descends. That humor drying becomes stone without weight, and main- tains the same form as the animals that have left their impression there, and of which it incloses the bones.

The Taxation of Revolvers. The fol- lowing, from the London Lancet, will ap- ply with equal force in this country, where, in not a few cases, the boys even indulge in the senseless and dangerous practice of car- rying fire-arms : " The dangerous folly of carrying revolvers was once more illustrated in a case recently tried in the North London Police Court. In this instance a young man, described as being most respectably con- nected, though without occupation, was ac- cused of threatening to shoot a policeman with whom he had had an altercation. Though he had been drinking, he was not intoxicated. A revolver loaded in two chambers was taken from him. The case

��is exactly typical of its kind, and requires no further explanation to show the hazard and the uselessness of this custom of ha- bitually carrying fire-arms. Entirely need- less for purposes of self-defense, they may become at any angry moment the instru- ments of hasty and irreparable crime. An- other minute and the policeman might have been a corpse and his assailant a foredoomed murderer, all for the sake of a petty differ- ence of opinion. Most persons, we feel sure, will agree with us that the time is over- due for some restrictive measure which will abate this growing nuisance. We would, therefore, advocate once more the imposi- tion of a sufficiently heavy tax upon the possession of these weapons, and of regis- tration in each case of sale. To regulate by such restraints an idle practice and a constant menace to public security implies no injury to, but rather a needful care for, private rights."

The Pamir Table - land. The name Pamir is not properly the name of any par- ticular spot, but means the country of frozen winds. It is well fitted to the region to which it is applied a table-land in central Asia, having the height of the Jungfrau, one of the highest of the Alps, and a super- ficial extent of a hundred thousand square kilometres. In consequence of its height, although it lies in the latitudes of southern Spain, its climate is extremely rigorous. The snow-line varies somewhat, at a height of about fifteen thousand feet, and the zone of cultivation rises to within about fifteen hundred feet of it. Within this zone cereala are raised, and a few good pasture tracts are found here and there. Forest growths are wanting.

About Certain Dye-stnffs. The princi- pal dye-woods of the Argentine Republic are the Quebracho Colorado, the Algorrobo bianco, the CorovMo, and the Lapacho. The extract of the quebracho, the chemical con- stitution of which has not been ascertained, when dried, gives an almost bla.ck substance, brittle, and having a characteristic luster. It is used alone to dye wool, and with mor- dants. The brownish-black sap of the al- gorrobo gradually solidifies in the air into a resinous and gummy substance that wholly

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��dissolves in water, or into delicate, viscous, and somewhat tough superficial lamina?. Without using any Mordant, it produces very fast colors in wool, silk, cotton, and linen goods, varying, according to the appli- cation, from the clearest to the blackest brown. The corovillo affords a deep scarlet color, the preparation and application of which are a secret known only to a few fam- ilies who keep it well. The acid extract from the lapacho lapachic acid appearing in greenish-yellow needle-crystals, affords, according to its treatment, rose-crimson, yellow, clear brown, and dark brown. The tree itself has some remarkable character- istics in the impenetrable density of its in- florescence previous to the appearance of the leaves, the firmness and strength of its wood and its freedom from ash, the resist- ance of the wood to decay, and the intense induration of its wood when soaked for a considerable time in water.

Speed Of Insects. "Flies," observes a writer in the London Spectator, "frequent the insides of our windows, buzzing slug- gishly in and out of the room. But what different creatures are they when they ac- company your horse on a hot summer's day ! A swarm of these little pests keep perti- naciously on wing about your horse's ears ; quicken the pace up to ten or twelve miles an hour, still they are there ; let a gust of wind arise and carry them backward and behind, the breeze having dropped, their speed is redoubled, and they return to their post of annoyance to the poor horse. But this example gives only a partial proof of the fly's power of flight. The present writer was traveling one day in autumn by rail at about twenty-five miles an hour, when a company of flies put in an appearance at the carriage-window. They never settled, but easily kept pace with the train ; so much so, indeed, that their flight seemed to be almost mechanical, and a thought struck the writer that they had probably been drawn into a kind of vortex, whereby they were drawn onward with little exertion on the part of themselves. But this notion was soon disproved. They sallied forth at right angles from the carriage, flew to a dis- tance of thirty or forty feet, still keeping pace, and then returned with increased

��speed and buoyancy to the window." The same writer estimates that the dragon-fly, which passes and repasses as in instantane- ous jerks, is capable of flying at a speed of from eighty to a hundred miles an hour.

Ambergris. The word ambergris is French for gray amber, which is a misnomer, for ambergris is a very different substance from amber. The latter is fossilized resin, and is therefore of vegetable origin, while the former is a product of some disease in the sperm whale. Ambergris is sometimes found in the intestines of the whale, but most of the supply is picked up in masses which float on the surface of tropical seas. The best ambergris is soft and waxy, gray in color, and streaked with different shades. It is opaque, inflammable, and remarkably light. It is found in the largest quantities near the Bahamas, but it is a scarce article at best, being quoted in New York at thirty- four dollars an ounce, wholesale. Its use is in perfumery, its great value being due to its powerful odor, which somewhat resembles that of musk, but is much more lasting. It is so peculiar that it has never been success- fully imitated. Ambergris is so costly that it is one of the most adulterated articles known in commerce. It is too costly to use alone, but a small quantity of its solution in alcohol is mixed with other perfumes, the blended odor of which it intensifies. A grain or two rubbed down with sugar is often add- ed to a hogshead of wine, to which it gives a pleasing fragrance. A handkerchief per- fumed with the famous Parisian compound perfume, extrait d'ambre, will retain the odor after several washings.

Strength of the Earth's Crnst. In esti- mating the strength of the earth's crust, Mr. G. K. Gilbert uses the term crust to in- dicate the outside part of the earth, without reference to the question whether it differs in constitution from the interior. The con- ditions of the problem are illustrated by supposing a large tank of paraffin with level surface. If a hole be dug in this and the material piled up at one side, the perma- nence of the hole or heap will depend on its magnitude. Beyond a certain limit, further excavation and heaping will be compensated by the flow of the material. Substitute for

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��paraffin the material of the earth's crust and the same result will follow, but the limitations of the hole or heap will be dif- ferent, because the strength of the mate- rials is not the same. Assuming the earth to be homogeneous, the greatest possible stable prominence or depression is a meas- ure of the strength of the material. Hav- ing examined a marked example of elevation and depression in the region of the Pleisto- cene Lake Bonneville and the Wahsatch Mountains, the author deduces the working hypotheses that the measure of the strength of the crust is a prominence or cavity about six hundred cubic miles in volume ; and that mountains, mountain ranges, and valleys of magnitude equivalent to mountains, exist generally in virtue of the rigidity of the earth's crust ; continents, continental pla- teaus, and oceanic basins exist generally in virtue of isostatic equilibrium in a crust heterogeneous as to density.

The Dragon-fly and the Cricket. Mr.

E. Giles relates, in the Journal of the Bom- bay Natural History Society, that in June, 1888, his attention was attracted by a large dragon-fly which was cruising backward and forward in his porch in an earnest man- ner that seemed to show that he had some special object in view. Suddenly he alight- ed at a small hole in the gravel and began to dig vigorously, sending the dust in small showers behind him. " I watched him," says Mr. Giles, " with great attention, and after the lapse of about half a minute, when the dragon-fly was head and shoulders down the hole, a large and very fat cricket emerged like a bolted rabbit, and sprang several feet into the air. Then ensued a brisk contest of bounds and darts, the cricket springing from side to side and up and down, and the dragon-fly darting at him the moment he alighted. It was long odds on the dragon-fly, for the cricket was too fat to last, and his springs became slower and slower, till at last his enemy succeeded in pinning him by the neck. The dragon- fly seemed to bite the cricket, who, after a struggle or two, turned over on his back and lay motionless, either dead or tempo- rarily senseless. The dragon-fly then, with- out any hesitation, seized him by the hind legs, dragged him rapidly to the hole out of

��which he bad dug him, entered himself and pulled the cricket in after him, and then, emerging, scratched some sand over the hole and flew away. Time for the whole transaction, say, three minutes."

Evolntion in Floridian Shells. Except Mr. Edward Potts's article on Fresh-water Sponges collected in Florida, all the papers in Vol. II (December, 1889) of the Trans- actions of the Wagner Free Institute of Science of Philadelphia are by Prof. Joseph Leidy. They are on Some Fossil Human Bones ; Mammalian Remains from a Rock Crevice in Florida; Mammalian Remains from the Salt Mine of Petite Anse, Louisi- ana ; Platygonus, an Extinct Genus allied to the Peccaries ; and The Nature of Organ- ic Species. The last paper relates to a se- ries of shells found in Florida which appear to illustrate the transmission or evolution of an extinct form [Fulgur contrarius) into that of a living species {Fulgur perversus). The changes are illustrated by engraved plates. In this series, as also in a series of Strombus, great variability seems to have prevailed among the fossil forms, while the existing species are comparatively stable. Another shell, the Mchngena coronata, found in the same bed, manifests great uniformity in structure ; " while, at the present time, it is probably the most variable shell living on the coast of Florida. . . . We thus find in the same bed one genus that was widely variable in character which now manifests much greater stability in structure ; and also two genera that were quite fixed or stable that at the present time are very in- constant." In explanation of this anomaly Prof. Leidy suggests that " no species has been found to be constant or permanent during a long period of geological time; and there appear to have been periods of rest and periods of activity in the transmu- tation of species. Surviving from the Mio- cene age, the Fulgur -contrarius may have been ripe for a change, which was stimu- lated into action by a cause that would not affect other species, especially such as had not been in existence long. For the same reason the Melongcna coronata and the Strombus pugilis may be active in their in- constancy now, as they have survived from a former period."

�� � Ancient Maps of the Egyptian Desert. — Mr. Cope Whitehouse called attention, in the British Association, to some points in connection with ancient maps of Egypt, Lake Mœris, and the Mountains of the Moon. The revised map of Egypt prepared by the Intelligence Department of the War Office shows a part of the changes effected by the observations of the author. A critical study of the manuscript and printed maps attached to the text of Claudius Ptolemy had enabled him to aver, as a crucial test of their authenticity, that a depression would be found to exist in the desert to the west of the Nile and to the south of the Fayoum. The physical conditions of this region have now been determined with extreme accuracy. The most important maps of the printed editions of Claudius Ptolemy, of the sixteenth and seventeenth centuries, have been reproduced in the fac-simile atlas of 1890. Mr. H. M. Stanley's identifications of Ruwenzori with the Mountains of the Moon reversed this method. He found the mountains and then examined the maps and the historical evidence. The existence of ancient originals from which the mediæval copies were made is no longer open to dispute. They have never been submitted to critical analysis. It is reasonable to anticipate other important additions to geographical knowledge as the result of the renewed credit which will henceforth attach to the only atlas which has reached us from ancient days.