Popular Science Monthly/Volume 24/April 1884/Popular Miscellany
Durability of Building Stones.—Dr. Alexis A. Julien has made examinations of buildings of various ages, and of tombstones in some of the older grave-yards around New York city, to assist in determining the durability of the various stones used in building. The coarse brown-stone, which is largely employed, appears to be one of the most perishable materials in use, so that many builders are returning to brick, although the finer varieties of brown-stone are better and compare favorably with other materials. Among the causes for the decay of this stone are mentioned, erection on the edge of lamination, the heat of the sun on exposed sides, and imperfect pointing, with poor mortar, which falls away and leaves the joints exposed to the weather. The presence of sea-salt in the atmosphere has exerted no appreciable effect, and lichens growing on the stone do not appear to have occasioned any decay or corrosion. The light-colored Nova Scotia sandstones have been too recently introduced to show marked defect, but evidences of exfoliation and of slight moldering in damp spots have begun to appear. Buildings constructed of the Amherst (Ohio) sand-stone show little decay, only discoloration; and that is regarded as a favorable sign rather than otherwise, for it indicates durability, while a stone that cleans itself does so by disintegration of its surface, the grains dropping out and carrying away the dirt. The coarse fossiliferous limestone from Lockport has disintegrated rapidly within the last ten years, chiefly on account of careless arrangement in masonry. The oölitic stone from Ellettsville, Indiana, shows an almost immediate and irregular discoloration, said to be produced by the exudation of oil. The oölite from Caen, France, has shown decay in several instances where it was not protected by paint. The dolomitic marble of Westchester County has decayed considerably after sixty years of use, but much of this is owing to the stone having been improperly laid. Often marbles, of various kinds, in tombstones, are in fairly good condition. Horizontal slabs show a tendency to bend. The frequent obliteration of inscriptions, the general and often rapid granulation of the surface, and the occasional Assuring of slabs, show that the decay of marble—in the varieties hitherto long used in New York city—is steady, inevitable, and but a question of time; and, if unprotected, this material is likely to prove utterly unsuitable for out-of-door use, at least for decorative purposes or cemetery records, within the atmosphere of a city. A blue-stone, or graywacke, is yearly coming into more general use, and, though somewhat somber in tone and difficult to dress, seems likely to prove a material of remarkable durability. The bluish Quincy granite has been used in many buildings, and rarely shows as yet many signs of decay. A fine-grained granite from Concord, New Hampshire, also promises to be durable. The light-colored and fine-grained granite of Hallowell, Maine, in which the white feldspar predominates, has shown some exfoliation, but in the single building in which this is remarked the stones appear to have been set on edge, and, as their structure is laminated, that is an important matter. "The weathering of granite does not proceed by a merely superficial wear, which can be measured or limited by fractions of an inch, but by a deep insinuation along the lines of weakness, between grains, through cleavage-planes, and into latent fissures. Thus, long before the surface has become much corroded or removed, a deep disintegration has taken place by which large fragments are ready for separation by frost, from the edges and angles of a block. When directly exposed to the heat of the sun, an additional agency of destruction is involved, and the stone is suddenly found ready to exfoliate, layer after layer, concentrically." The following is an approximative estimate of the "life" of different kinds of stone, signifying by the term life, without regard to discoloration or other objectionable qualities, merely the period after which the incipient decay of the variety becomes sufficiently offensive to the eye to demand repair or renewal: coarse brown-stone, five to fifteen years; laminated fine brown-stone, twenty to fifty years; compact fine brown-stone, one hundred to two hundred years; blue-stone, untried, probably centuries; Nova Scotia stone, untried, perhaps fifty to two hundred years; Ohio sandstone (best 856
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��ceous variety), perhaps from one to many centuries ; coarse fossiliferous limestone, twenty to forty years ; fine oolitic (French) limestone, thirty to forty years ; fine oolitic (American) limestone, untried here; coarse dolomite marble, forty years ; fine dolomite marble, sixty to eighty years ; fine marble, fifty to two hundred years ; granite, seventy- five to two hundred years ; gneiss, fifty years to many centuries. Many of the best building-stones in the country have never yet been brought to the city.
Peroxide of Hydrogen. Peroxide of hydrogen, though it was discovered in 1818, has only recently, by the aid of cheapened processes of preparation, come into general use. When pure, it is a colorless liquid, which in decomposing gives off four hundred and seventy-five times its volume of oxygen. Diluted solutions of it, kept in the dark at a temperature of not more than 80, may be preserved for a very long time without decomposing. It is obtainable pure, in large quantities, and cheaply, in solutions of three per cent by weight or ten per cent by volume ; and it has come into extensive use as a bleaching agent, for disinfection, household purposes, and the toilet. It is the really operative agent in air-bleaching on the grass, which has been in use from time immemorial, and is well adapted for bleach- ing substances of animal origin, in which chlorine agents often fail. In using it the substance to be bleached must first be care- fully cleansed from dirt and oil. It may be applied as a bath in the shape of a weakly acid solution neutralized with a few drops of ammonia, or the substance may be dipped in it, and afterward slowly dried in the air. As the water evaporates, the con- centration of the peroxide of hydrogen in- creases, and the bleaching goes on more energetically. Dumas and Pettenkoferhave applied peroxide of hydrogen with much success and satisfaction to the clean- ing of oil-paintings and engravings. This substance has recently been found to be one of the most valuable and effective dis- infecting agents. In the household it has proved to be equal to the best of other known substances for purposes of washing and cleansing the person. It is adapted to the most tender skins. It has been pro-
��nounced preferable as a tooth-wash to all powders and to all other preparations which do not depend upon it. In bathing, with the addition of a drop or two of hartshorn, it quickly disintegrates and removes the dead skin without affecting the living tissue, except to make it more healthy and hardy. It is a salutary hair-wash, provided the hair has been prepared for it by previous wash- ing with soap or spirit. Professors Alex. Classen and 0. Bauer have found it a pow- erful agent in analytical chemistry. Die Natur.
Fact and Fancy regarding Fingal's Cave.
At the Montreal meeting of the American Association in 1882, Mr. F. Cope Whitehouse offered a paper on " The Caves of Staff a, and their Connection with the Ancient Civ- ilization of Iona." The Committee on Pa- pers, having heard Mr. Whitehouse in ex- position of his views, and examined his maps and drawings, and the testimonials which he was able to produce from men of authority in science, adjudged that there were sufficient merit and originality in his paper to justify giving it a hearing. The article was also regarded by us of enough interest to be given to the readers of " The Popular Science Monthly " in De- cember, 1882 ; and a summary of it was published in " Notes and Queries," Decem- ber 28, 1883. In it the author, regarding the situation of the Island of Staffa, which is shown in the map, the character of its
���rocks, the form of Fingal's Cave, and the shape and direction of its exposure, con- cluded that it was extremely unlikely that the cave could have been hollowed out by the natural action of the waves, and suggested the question whether it might not have been artificially excavated. The paper has not yet been adequately an-
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��swered. But the author was held up to ridicule, in a leading article in " Nature " of January 25, 1883, as the victim of " a thirst for scientific renown," who knew nothing of the subject concerning which he had given the result of his studies, but had succeeded in imposing himself upon a re- spectable scientific body, and upon a scien- tific journal. Mr. Whitehouse has taken his time to answer this attack, and has replied to it with vigor and to the point in a late number of the " Manhattan." Setting by the side of one another photo- graphs of the Island of Staffa and Fingal's Cave, and the representations of them given in the current works on geology, he shows that a wonderful ignorance of what they are like exists in the scientific mind, and is transmitted to students. German works ex- hibit a structure supposed to have been ex- posed for millions of years to waves capable of hollowing out two hundred and twenty- eight feet of basalt, and open at both ends, which Fingal's Cave is not, compared with which u a wall of bricks without mortar would be solidity itself." Hitchcock's " Geol- ogy " long gave a view that did not show any part of Staffa, but the adjoining Island of Boo-sha-la. Dr. A. Geikie, Director of the Geological Survey of Scotland, gave, in his "Primer" in 1881, u a tolerable engraving of part of the island" ; but, in 1882, he of- fered to more advanced students, in his "Text-Book of Geology," "a problem in physics and drawing which has hitherto passed uncriticised," " the bad copy of a picture for which its author apologized in 1819," " which picture was no more Staffa than a view inside the railings at the head of Wall Street would be Trinity Church." If our young American has been too hasty in his theories, upon which we do not under- take to decide, it certainly behooves his crit- ics, and especially those who are on the spot and wear official titles, to attempt some ap- proach to accuracy in fact.
Why some Bodies feel colder than oth- ers. It is a familiar fact that, when we touch with the fingers different substances of the same temperature, some will feel colder than others. The differences of the feeling are commonlv ascribed to differences in the heat-conducting powers of the several
��bodies. A correspondent of " La Nature " suggests that, besides this, the specific heat of the bodies and the degree of polish of their surfaces should be taken into account. The effect of specific heat may be observed by pouring alcohol upon water and plung- ing the finger in so that a part of it shall be in the water and a part in the alcohol. The part in the water will feel much colder than that in the alcohol. So brandy may be taken, with safety, at a degree of cold at which water would infallibly irritate the skin. The effect of the degree of polish may be tried with a piece of marble or glass one side of which is smooth and another rough, with a file one side of which has been ground down, or with glazed and un- glazed paper. In every case the smooth side or substance, at ordinary temperatures, will appear colder than the rough one. The fact may be accounted for by remembering that the smooth body presents vastly more points of contact with the fingers, and con- sequently more conductors for the heat than the rough one. In like manner a liquid al- ways seems colder than the vessel contain- ing it, because it is in closer contact with the skin.
Are there Birds with Teeth 1 The
"Transactions" of the Natural History Soci- ety of Leipsic contains a paper by Dr. Paul Fraisse, on teeth and tooth-papillae in birds. It is generally admitted that there is a se- ries of birds having real teeth in their bills. Among these are the fossil archaeopteryx of Solenhofen, and the odontornithes, discov- ered by Professor Marsh in the North Ameri- can cretaceous. The jaws of the latter birds were furnished with teeth, and also with cavities containing supplementary teeth, like those of crocodiles. The curious relations which these birds exhibit with reptiles, as a kind of transitional stage between the two orders, suggest the question whether any living birds have teeth. On this point, Dr. Fraisse remarks that Geoffroy Saint-Hi- laire in 1821 discovered in two embryos of the parrot (Palceornis torquatus) papillae which he regarded as tooth-sacs and as ho- mologous with the rudimentary teeth of oth- er animals. In one of the jaws there even seemed to be duplicate rudiments, as among the mammalia. Cuvier accepted this an-
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��nouncement with a kind of reserve, and re- marked that the horny texture of the bill seemed to spread over these vascular papil- lae much in the same manner as the enamel over mammals' teeth. Blanchard resumed the investigation in 1860, and found in cer- tain birds, among them some parrots, for- mations imbedded in the jaws, which when microscopically examined presented consid- erable similarity in composition with den- tine and in structure with teeth ; and he concluded that those birds possessed a real dental system. Dr. Fraisse believes that pa- pillae are frequently present in the horny bill of the parrot, that they are rich in ves- sels and covered with a veneer of peculiarly adapted horn-cells which Blanchard took to be dentine, and which in microscopic sec- tions have quite a resemblance to that for- mation ; but that real teeth do not exist in birds. " Whether any first rudiments of teeth may have been the origin of the growth of horn-teeth is very doubtful ; but in all probability the horn-teeth should be regard- ed as secondary formations." The teeth of the odontornithes, in which Professor Marsh has found dentine and enamel, are excepted from this conclusion.
Alcohol regarded as a Beneficial Agent.
Dr. William Sharpe, an English physi- cian, has published a pamphlet in which he seeks to demonstrate that alcohol is a fac- tor in human progress. Looking into the history of the subject, he finds that the vine and the product of the vine have been in olden times more intimately associated with man's intellectual growth and development than with his purely physical wants. The stimulus of alcohol, when judiciously con- trolled, "always leads to active and higher mental efforts on the part of individuals," thus producing a contrary effect to that of other stimulants, which tend rather " to bring about a contented state of dreamy in- action " and to repress effort. " To under- stand fully," he says, " the beneficial action of alcohol as regards mental development, we must first get a clear view of the value of those states of cerebral excitement which most people, though in varying degrees, ex- perience something of, rising as they then do mentally above the level of what may be called their ordinary every-day thoughts.
��This is not difficult, if we bear in remem- brance that it is during such periods of high mental activity, in which the mind, tran- scending the more circumscribed limits of reason, sweeps intuitively into the veiled and distant regions of universal truth, that all great conceptions arise and have arisen in times past, crudely at first it may be, but which, nevertheless, when reduced to order and embodied in works, have been of ines- timable value to mankind. . . . The stimu- lus produced by alcoholic liquors, if not nearly of so high an order, is more easily called into play, while in a practical sense, the latent ability being present, it is more vigorous and effective as regards actual work. Hence the value of alcohol, as a stimulant, lies in the fact that it produces artificially and sustains temporarily that state of mental excitement or exaltation ne- cessary to the conception and projection, though not to the detailed elaboration, of those enduring works that, whether in the domains of art, architecture, or engineer- ing, are remarkable for boldness of execu- tion, originality, and grandeur of design ; and further, that it is the only manageable stimulant which, when used in moderation, and in the form of wine or spirits, is not only not injurious, but conduces to the gen- eral health, while it favors both mental and physical development." Dr. Sharpe also as- signs to alcohol a beneficial agency in stimu- lating genial thoughts and feelings.
Japanese Lacqners. The Japanese dis- tinguish in lacquers between crude lacquer, which is obtained from the trunks of live trees and forms the basis of nearly all the mixtures used in making lacquer-ware ; branch lacquer ; and black lacquer, a prep- aration. The yield of branch lacquer is only about one per cent in comparison with that of other lacquers, while the proportion of ninety per cent is required in working. Hence a mixture is made of various kinds of lacquers, sea-weed jelly, finely grated sweet- potatoes, and as much soot as is needed to color the mass. Each manufacturer has his own special mixture, but the extraneous ad- ditions are believed not to injure the qual- ity of the whole. True branch lacquer be- comes extremely hard when dry ; but, since when used alone it will not dry under some
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��twenty days, the pure sap is now but little used. The black lacquer is made by adding to crude or branch lacquer about five per cent of the tooth-dye used by women, a liquor formed by boiling iron filings in rice- vinegar, exposing to the sun, and stirring frequently for several days. In preparing all the lacquers it is an essential object to get rid of the water that exudes from the tree with the sap. This can not be effected without adding water, which is done in small quantities, three times a day, for two or three days. All the water then evaporates together. No lacquer will dry till this pro- cess has been gone through. If crude lac- quer, which is originally of the color and consistency of cream, is exposed to the sun for a few days without adding water, it be- comes black, or nearly so, thinner and trans- lucent, but will not dry if applied to an ar- ticle. If, now, water is mixed with it, it at once loses its black color and its transpar- ency, becomes again of a creamy color, only slightly darker, and can be used after evapo- ration of the water, like any ordinary lac- quer, and will dry. The greatest difficulty the lacquer-workers have to contend with is that of obtaining a clear, transparent var- nish. What is called transparent varnish is really black to the eye, and has to be ground and polished after application before it will present a brilliant surface.
Superstitions about Stone Implements.
Richard Andree, a German anthropologist, has remarked that, wherever prehistoric stone implements have been found, whether in Europe, Asia, Africa, or America, identical ideas, agreeing frequently in the minutest particulars, have been associated with them in the popular mind. It is really astonish- ing to find the negroes, the South American Indians, the Burmese, and the different Eu- ropean stocks entertaining the same super- stitions respecting the origin and supposed wonderful properties of the stone axes. Such conceptions must be regarded as compara- tively new, for they can only have origi- nated after the implements had gone out of use, and the casual finding of them would be capable of exciting a mystified curiosity. They would naturally appear to the finders, who had no idea of their use, as something wonderful, perhaps having their origin in
��another world ; and it would also be natural to attribute mysterious properties to them. The fall of meteoric stones would give a kind of a justification to such notions. People everywhere have thought the stone imple- ments were the product of the lightning, or its bolts, and that the noise of thunder was caused by their striking the earth ; and the belief is very common that the " thunder- axe," which is driven deep into the ground, will gradually rise to the surface again in the course of some definite period, as seven days, weeks, or years. The finder of one of these mysterious objects esteems it highly on account of the peculiar properties attrib- uted to it, and transmits it to bis posterity. Such stones are regarded as amulets in Asia and Europe, and as fetiches on the Guinea coast. They are believed to preserve one against harm, to prevent sterility in women, to give protection against fire and lightning ; treasures are sought with them, and most effective medical properties are attributed to them. They have been believed to have a kind of life, and to sweat on the approach of a storm. These superstitions have no footing among people who are still in the stone age and acquainted with the use of stone implements. Thus, no trace of them is found in the South Seas and Australia ; although a foundation for them appears to be laid among the West Australians, in the shape of a belief that certain smooth, oval stones have fallen from the sky.
A Subterranean River in Austria. One
of the recent publications of the Austrian Tourists' Club contains a description of the " Recca Cave," which it is claimed must be ranked among the greatest natural curiosi- ties of the Austro-Hungarian monarchy. The cave is situated near the middle of the Karst mountain-land, in the bare and sterile plateau that spreads out above Trieste, in a region rich with caves, and has been formed by the flow of the Recca River under the cre- taceous hills. Similar river-excavations are common in the region, but that made by the Recca surpasses all the others in extent. Near the railroad-station of Vistrica-Ter- novo, the Recca is a stream some fifteen or twenty paces broad and two or three feet deep. Thence it flows along the border of the chalk and tertiary formations in a deep-
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��ly cut but pleasant valley, till it comes to a point where the chalk crosses its course in a semicircular range, and seems as if it would stop its further progress with a dam nearly four hundred feet high. The river has, however, conquered this wall by boring under it a tunnel fifty feet high and half as wide, through which it rushes in a very live- ly torrent. In the course of a little over a hundred yards, it passes a chimney-shaped shaft, which extends to the whole height of the mountain end presents an opening more than thirty feet in diameter at the surface. After another hundred yards the stream crosses the floor of a doline (or sink-hole) four hundred feet broad, and then, after crossing a narrow ledge, enters the great doline of St. Canzian. Here the steep, fre- quently impending rocks on three sides form a gigantic kettle, the western wall of which falls perpendicularly more than five hundred feet. On the southern side a turf-covered slope descends toward the bed of the river, to end abruptly in a precipice of nearly two hundred and fifty feet. Having twice bored the hills for relatively short distances, the Recca continues its course till it meets the rock-wall a third time and excavates a third subterranean channel, this time of thirty- five kilometres, or twenty-two miles. This is the Recca Cave proper, and from it the stream emerges near San Giovanni di Duino into the important river, though a short one, the Timavo, the mystery of the origin of which has been solved by this tracing of the course of its main affluent.
Scottish and Irish Crannogs. Dr. Rob- ert Munro, in his "Ancient Scottish Lake- Dwellings or Crannogs," draws a parallel between the island-fortifications of the west- ern Celts and the lake-dwellings of Switz- erland, and then suggests a connection of development between the crannog and the moated castle of the middle ages. "Cran- nog " is a Gaelic term, from crann, a mast or tree, and seems to point to the fact that wooden piles or tree-trunks formed an im- portant part in the structure. While the crannogs have several features in common with the Swiss pile-dwellings, they exhibit also some important points of difference, whereas the Irish and Scottish structures are essentially similar. The latter were
��really fortified islands, sometimes natural) but generally artificial. When complete and in use, they would present the appear- ance of small islands surrounded by strong palisades for defense, with buildings of va- rious kinds on their surface, dug-out canoes ready for use, and in some cases a causeway or gangway communicating with the shore. They were certainly built with great skill, and with a solidity of which the endurance of parts of them to the present time is the best evidence. Stone weapons have been found in the crannogs, but the bulk of the remains they yield are of bronze and iron, and some of the coins and pottery point to Roman influences. It is generally admitted that even the Irish crannogs are long sub- sequent in date to the earlier Swiss lake- dwellings. The crannogs, moreover, con- tinued much longer in use than the cor- responding lake-dwellings in Switzerland ; those of Ireland down to the seventeenth century, those of Scotland to a century or two earlier. They were evidently used mainly for defense. In the more northern and wilder parts of Scotland the wooden structures gave way to stone castles, and in the end, as Dr. Munro points out, instead of the castle being brought to the water, the water was brought to the castle in the shape of a moat. It is certainly possible that some individual castles may be the di- rect representatives of former crannogs, but it would be very hard to prove that there has been, as Dr. Munro seems inclined to think, any general connection of the kind between the two structures.
Effects of Gases on Insects. Mr. L. P.
Gratacap reports, in the " American Natu- ralist," respecting experiments he has made upon the power of different insects to live in various gases. The Colorado beetle proved the hardiest of them ; it was killed outright in the vapor of prussic acid, which it, however, stood longer than any other in- sect experimented with, while it was para- lyzed for a time in illuminating gas, and died after two hours' imprisonment in nitrous oxide. The effects of oxygen were not very marked ; hydrogen produced lethargy in flies, and was bad for snapping beetles, moths, and a wasp ; carbonic acid killed flies at once, and threw Colorado beetles on their
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��backs ; carbonic oxide killed ants, but not Colorado beetles ; prussic-acid vapors and nitrous-acid fumes destroyed everything, as did chlorine everything but Colorado bee- tles ; nitrous oxide exhibited but slight ef- fects ; and illuminating gas appeared to produce death if the exposure was long enough. Mr. Gratacap recommends charg- ing from time to time with illuminating gas as probably, and charging with diluted prus- sic-acid fumes as certainly, an efficient pre- ventive of the ravages of insects in cabinet cases.
Backsheesh in Areadia. " How much to be envied are you Singalese ! " says Ilerr Haeckel, in his " Indian Letters of Travels." "You are not troubled either about the cares of to-morrow or of the distant future. What you require for your own life and your children's grows of itself at your mouth ; and whatever else you may want in the way of luxury you can get with the slightest exertion. You are, indeed, like the lilies of the field, that grow around your simple huts ; they sow not, neither do they reap, and still heavenly Nature feeds them. You are not excited with political or military am- bitions ; no anxious thoughts about busi- ness, or the rise and fall of stocks, disturb your sleep. The highest honors, titles, and orders of civilized men are unknown to you. Yes, I believe it fully, you do not envy us Europeans for our thousand superfluities ; you are happy in being simple men, Nature- men, living in a paradise, and enjoying that paradise. Yes, what care -burdened civil- ized man would not envy you your simple condition, and your paradisiacal content- ment ? " A few moments after indulging in these reflections, Herr Haeckel reached the last post-station before arriving at Point de Galle, and was still thinking he had come upon a place where the struggle for exist- ence had no being. His porters awakened him from his dream by speaking to him of their "backsheesh." It was now time to attend to that matter, for it might be for- gotten, in the hurry and confusion, if it was put off till they got to the city. Herr Haeckel had remarked that a native gentle- man had given each of the porters a " double anna," and reasoned that, in consideration of bis superior distinction as a u white man,"
��it would be proper to quadruple the amount and give a shilling. The porters returned the coins with irritation, and gave their pa- tron a very flattering lecture about the dis- tinction to which he was entitled by reason of his purely white skin. The main point which they presented was, that every white man ought to give double what he had given, or a rupee ; but that as white a man as he was, with his light hair, must belong to the very highest caste, the dignity of which would be suitably maintained by a still larger gift. Without acceding to the full force of this complimentary argument, Herr Haeckel yielded so far as to give the full white man's backsheesh of a rupee to each man, and had the pleasure of hearing himself pronounced a perfect gentleman.
The Chinese Superstition of Severed Queues. Dr. D. J. MacGowan, in a report on the health of Wenchow, has published some facts concerning " epidemic frenzies," or " popular crazes," which frequently pre- vail among large portions of the Chinese population. One of them raged very exten- sively in 1876, when it was believed super- natural agencies were at work cutting off the queues of the people. A sorcerer, get- ting possession, with the aid of a spirit, of one of these queues, was believed to be able thereafter to evoke at will the soul of the owner and use it as a servile demon, while the man was fated to die. The only remedy within the reach of a person who has lost his queue is to cut off an inch or more of what hair he has left and soak it for eighty days in a cesspool ; by this means the mys- terious connection between the hair remain- ing on his head and that in possession of the sorcerer is severed. Amulets and charms are, moreover, relied on for the prevention of disaster to the queue. A charm for this purpose was invented by the Governor of Kiang-Su, who also recommended an anathe- ma attributed to Tao Tse, which was to be chanted while copying it on yellow paper with the blood of a cock mixed in vermil- ion, after which the paper was to be burned and the ashes swallowed. The panic was created by some revolutionists, who secretly cut off the queues of a few passers-by in each large city, and then proclaimed that a diabolical agency was at work.
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��The Pygmies. Dr. Emin Bey gives in a recent number of Petcrmann's " Mittheil- ungen " some later notices of the Akkas, the pygmy race discovered in Africa, and first described by Schweinfurth. They are a hunting people, divided up into numer- ous tribes that do not mingle "with one another. They have no fixed abodes, but wander around in the countries of the Mon- butte and the Amadi. When a small soci- ety of them sojourns temporarily around the settlement of some chief, they build little huts for the married ones, while the unmar- ried satisfy themselves with mere shelters from the sun. Usually they live in the groves that line the streams, which afford them game and good hiding-places. The chiefs provide them with grain and roots, and take their pay in the proceeds of the hunt. The Akkas are vengeful and dan- gerous when offended, and are skilled in the use of the bow and arrow. Emin Bey's measurements gave heights of between four and four and a half feet for full-grown Ak- kas. The color of their skin varies from a clear yellow to a glistening red. The whole body is covered with a thick, stiff, filthy growth of hair. A disposition of the skin to wrinkle, peculiarly observable in the eye- lids, makes them look much older than they are.
Origin of Fires in London. The statis- tics of fires in London for the thirteen years, 1870-'S2, state the origin and nature of 22,262 fires, of which ten per cent at- tained serious proportions. The most fires were started in private houses, but they were the least dangerous ones, for only 2*4 per cent of them became serious, while in such establishments as saw-mills, furniture ware-rooms, rag-stores, and builders' shops, more than one fourth of the fires were de- structive. No particular influence of sea- sons in promoting or diminishing the dan- ger of fires appears from the London re" ports, where the difference in the number of outbreaks in the several months is com- paratively small and irregular, but in agri- cultural districts the most fires seem to take place in July and August. According to the facts presented by Mr. W. G. McMillan, in a lecture before the Society of Arts, the distribution of fires over the hours of the
��day seems to be governed by a distinct and well-defined law. The curves illustrating the hourly distribution, through several years, show a remarkable symmetry and a wonderful agreement in general form. The most outbreaks occur between eight and nine in the evening, whence the numbers fall somewhat rapidly to a minimum at be- tween six and nine in the morning. Thence the curves rise gradually to the evening maximum. By far the greatest number of the fires recorded originated in the use or abuse of light- and heat-giving apparatus. The most prolific source of danger still ap- pears to be the candle, less dangerous than when the old-fashioned, spark-emitting tal, low-candles were in use, but still operative by means of the ease with which it may be set under a shelf or carried within reach of light drapery. Surrounding the candles with tall shades like lamp-chimneys is rec- ommended as a precautionary device. Pe- troleum is, with due precautions, a safe fluid, but there are other burning-fluids, and some kinds of petroleum, that are highly dangerous. Coal-gas is entirely safe, except from the danger of leaks at the joints of the pipes, which may be guarded against; but all burners should be fixed, else they may be carelessly brought within reach of drapery. Many fires are caused by careless- ness in throwing away matches after they have been used. Directly and indirect^, artificial heating is responsible for a large proportion of fires. It operates through sparks shot out from open grates ; through defects in flues ; through the proximity of wooden beams and planks to flues, steam- pipes, or register- furnaces ; and through carelessness in disposing of hot ashes. The red fire used in theatres is very liable to spontaneous combustion ; plumbers some- times allow their portable furnaces to set fires ; and the sun shining through a body so shaped as to act as a lens to concentrate its rays, has been known to set papers on fire. Water is still the cheapest and most effective extinguisher ; and other agents in use are good in their way. Gypsum, used as a plaster and in concrete, is an excellent fire-proofing material. Wood may be made uninflammable by painting it with asbestus ; by impregnating its fibers with such sub- stances as tungstate or silicate of soda, or
�� � with two soluble substances which, coming together, will form an insoluble one. If wood is impregnated, too, with a substance capable of volatilization, its taking fire will be delayed till the volatile substance has been driven off. Warning of fires is automatically and surely given by means of devices by which the expansion of a column of mercury by the developed heat is made to close the circuit of a galvanic battery and sound an electric bell.
The Sunny Skies of Kamchatka.— M. Leonhard Stejneger has published in the Norwegian journal, "Naturen," a paper on the fauna and flora of Eastern Kamchatka and the Commander Islands, which adjoin our own Aleutian Islands. While the climate of the islands is foggy and their vegetation scanty, Kamchatka is represented as rejoicing in Italian skies, smooth seas, and a mild temperature. The flora is so exuberant that some species, which only grow to be three feet high in Norway, there attain the height of a man. Among them are the birch, alder, willow, and service-tree, whose berries as well as those of a honey-suckle are finely flavored, and well relished by the inhabitants. The flowers of the wild rose, rhododendron, potentillas, and taraxacum, might be mistaken for Norwegian species. The birds are also well represented, and one of them, a warbler, is distinguished by a plumage that suggests the tropics, and a voice comparable with that of the nightingale. The fauna is generally palæ-Arctic, and few American forms are found.