Popular Science Monthly/Volume 27/August 1885/Popular Miscellany


Correction.—This year's meeting of the American Association for the Advancement of Science will begin Wednesday, August 26th; not on August 20th, as erroneously stated in the July Monthly.

Fallacies about Mines.—Mr. Albert Williams, of the United States Geological Survey, has recently exposed, in a brief monograph, some of the popular fallacies which exist, often to the detriment of miners' interests, regarding precious-metal deposits. First, are local prejudices against certain formations and in favor of others. Most of these prejudices have been contradicted in one way or another, and there is no sufficient reason that any one of the kinds of country rock prevalent in mining districts is more likely to contain metal deposits than another kind. The supposition that the richness of mineral veins usually increases with depth may or may not be justified in a particular case; the only way to find out is to examine. Miners have objections against "specimen" mines, or mines that give unusual superficial promise of richness. Here, again, the only test is by trying, and it is certainly profitable to work the mines so long as they make a paying return, while it will be time enough to stop when they cease to do so. Some miners have favorite strikes, and prefer to work in no others. They are as often wrong as right. One direction of strike may promise best in one locality, and the opposite direction in another. Another miner's fallacy is the belief that the appearance of ores is a trust-worthy index of their value. Such a belief, Mr. Williams observes, may seem self-evidently absurd to the experienced miner, but it nevertheless governs many prospectors, who hastily judge from the looks of the rock, when they should have waited for an assay. Notwithstanding the necessity exists for contradicting these fallacies, it would be unfair to infer that the whole subject of precious-metal mining is involved in doubt and perplexity. On the contrary, a great deal of solid fact is now established, room for which has been gained only by clearing away a mass of misconceptions. Much remains to be learned; in fact, the study of precious-metal deposits is only beginning. But it must be admitted that, on the purely practical side, great advances have been made.

Bark Dresses.—The tapa of the South-Sea Islanders is made from the bark of the paper mulberry-tree (Broussonetia papyrifera), and the bark clothing of the African tribes is prepared from trees of the same family. Dr. Schweinfurth describes one of these trees (Urostigma Kotschyana), which is called rokko in the country of the Niam-Niams, as standing before every hut, and as cultivated in Monbuttoland. The bark is most fit for use when the trunk is of about the thickness of a man's body. The whole stem is then peeled for a length of some four or five feet, and this without destroying the tree; for the juicy substance around the wood immediately granulates and shortly begins to form a new bark, which becomes fit for use again in about three years. Thus a tree, properly taken care of, may be made to furnish several suits of clothing during its lifetime. The rokko-bark much resembles that of the bass-wood in quality, except that the bark is not quite so thin. By partial maceration and much beating it is formed into a kind of thick and very pliant cloth. In a crude state it is grayish or yellowish, but steeped with a dye-wood it takes a brownish color like that of a common woolen cloth. It constitutes a valuable article of trade in the interior of Africa. The price varies considerably according to the color and quality, and the ornamented cloths are held as fancy articles, without having a fixed price. Of the colored goods, a dark-gray material is commonly worn by the Witchweri wizards; a dark-red is fashionable among well-to-do people; and a tan colored ground with stripes and figures in black, called mtone, was formerly worn only in royal families, and is still much affected by the nobles in Unyoro and Ruhama, while it has been to a considerable extent supplanted in Uganda by goods from Zanzibar. It can not be bought in the market, but any one who wishes to get a pattern of it must go to one of the great chiefs and give him ample satisfaction in return-presents. The other goods may be bought at their price in cows or cowries. The skins of cattle, goats, sheep and antelopes are also worn in parts of Africa, while the skins of leopards, monkeys, and cats are worn only by privileged persons of royal or noble families.

Private Encouragement of Research.—The fact that the recent proceedings of the Royal Institution acknowledge the gift of £100 by Mr. Warren De La Rue and 50 by Sir Frederick Bramwell to the fund for the promotion of experimental research supports the view that matters of this kind might be trusted to prosper as well under the encouragement of private interest and enterprise as when quartered upon the Government for subsidy. Liberal gifts are seldom wanting to anything that proves worthy of them; and in the former case research will be supported in proportion as it is industriously prosecuted and is of value; while under the Government plan, although enough show of work may be made to draw the pensions, it is by no means sure that so much pains will be taken to make the genuineness and value of the work demonstrable.

Eskimos in Ancient New Jersey.—Mr. A. S. Packard, who has been investigating the history of the Labrador Eskimos, has come to the conclusion that those people formerly had a more or less permanent foothold on the northern shores of the Gulf of St. Lawrence. If this was so, it seems not improbable that they may have made, in very early times, expeditions farther south, to Nova Scotia and New England. This thought leads the author to Dr. Abbott's theory, that the Eskimos inhabited the coast of New Jersey during the river terrace epoch, which he was at first disposed to reject. Examination, however, has led him to look with more favor upon it, and to think it not improbable that, long after the close of the glacial period, or after the ice had disappeared, and during the terrace epoch, when the reindeer and walrus lived as far south as New Jersey, the Eskimos, being perhaps the remnants of the palæolithic people of Europe, extended as far as a region defined by the edge of the great moraine; and, as the climate assumed its present features, moved northward. This view presented itself while he was collecting the material for his notes, and was confirmed by Mr. Tylor's remarks at the British Association.

The King Country and the Maories.—The "King Country" is a district of about ten thousand square miles in extent in the northern Island of New Zealand, to which the mass of the wild native population of the country have retired so as to be out of the way of the whites, and over which they claim and exercise exclusive jurisdiction to the extent of having, till very recently, held it tapu against white men. Mr. J. H. Kerry Nicholls, who lately succeeded in making a running exploration of it, describes it as one of the best-watered parts of the island, with many beauties, and offering many natural advantages for European settlement. In the west it has an extensive coast-line, and a capacious harbor. Dense forests cover a large part of its southern area, and extend northward to the mountains. Westward of this division is a considerable area of open country, while there are vast open tablelands near the snow-clad mountains in the south, and other extensive open plains west of the great Lake Taupo and north of Titiraupenga. The King Country possesses all the rock formations in which gold, coal, iron, and other minerals are found, while its extensive forests are rich in timber of the most varied and valuable kind. Geysers and thermal springs, possessing wonderful medicinal properties, are found in the vicinity of its many extinct craters; and, while it possesses one of the largest active volcanoes in the world, its landscape is also crowned by the snowy peaks of some of the highest mountains in Australasia. With these important features, it is endowed with scenery of the grandest order, and with a climate unsurpassed for its variety and healthfulness. According to Mr. Nicholls, the Maori people in New Zealand are decreasing; for, while in Captain Cook's time they numbered more than 100,000 souls, in 1881 the number had decreased to 44,099. The three principal diseases conducing to the decay of the race are phthisis, chronic asthma, and scrofula, the first two being principally brought about, Mr. Nicholls believes, by a half-savage, half-civilized mode of life, and the latter from maladies contracted since the first contact with Europeans. "It is, however, clear that there are a large number of natives yet distributed throughout the King Country, and among them are to be found, as of old, some of the finest specimens of the human race. A change of life, however, so different from that followed by their forefathers, has brought about a considerable alteration for the worse among the rising population, and, although during my journey I met and conversed with many tattooed warriors of the old school, who were invariably both physically and mentally superior to the younger natives, it was clear that this splendid type of savage will soon become a matter of the past. I found the natives living much in their primitive style, one of the most pernicious innovations, however, of modern civilization among them being an immoderate use of tobacco among both old and young." At Ruakaka, in the heart of the mountainous forest region, the Maories were found living in the same primitive way as in the time of Cook, and, "when we questioned them as to their religious principles, they told us that they believed in nothing, and got fat on pork and potatoes."

Water-Purification of Sewage.—The important part played by water in the oxidation of sewage has been tested by experiment, and may be accounted for by the quantity of free oxygen that water usually contains. The quantity that may be dissolved is increased with reduction of the temperature. At the summer temperature of 70° Fahr., water contains 1·8 cubic inch, and at the winter temperature of 45°, 2·2 cubic inches, of oxygen per gallon, which is equivalent to four or five cubic inches per foot. From calculations based upon these data, it will be seen that at a temperature of 70° there are 2·58 tons, and at the temperature of 45°, 3·16 tons, of oxygen in every 10,000,000 cubic feet of water. This shows a difference of more than half a ton per cubic foot between these two temperatures. It has been calculated that if a volume of water containing thirty-five per cent of sewage matter be allowed to flow for one mile, exposed to the air, the whole of the sewage would become oxidized. It has also been estimated, by experiment, that a closed vessel containing water, with five per cent of sewage, gives only thirty-two per cent of aeration on the fourth day, as compared with eighty-four per cent on the day when it is introduced into the vessel. The results of these experiments tend to show that, although the self-purifying power of the water of the river is sometimes overtaxed, it still retains the power of oxidizing sewage-matter; but the question as to whether it has the power of freeing itself from living bacteria still remains to be solved.

The Identity of American Races.—J. W. Powell writes to "Science," pertinently to its review of the Marquis de Nadaillac's "Prehistoric America," that, in his opinion, "there has never been presented one item of evidence that the mound-builders were a people of culture superior to that of the tribes that inhabited the valley of the Mississippi a hundred years ago. The evidence is complete that those tribes have built mounds within the historic period; and no mounds or earthworks have been discovered superior in structure or contents to those known to have been built in historic times." Nevertheless, Mr. Powell considers the doctrine of "the identity of all peoples that ever inhabited the American Continent up to the advent of Europeans" one that is not and can not be held by any intelligent anthropologist, except in some very broad sense, as, for example, that they belonged to the human race, or that they inhabited one continent. In respect to mythologies, languages, and institutions, there are, and have been, many distinct peoples; and, in respect to arts, there is much diversity, though arts travel from people to people with the greatest ease. At the present time we can not have fewer than seventy distinct peoples among the tribes of North America, and in antiquity the number may have been greater."

Savage Sharp-Shooting.—Concerning the manners and customs of the savages of Mount Sylvia, Formosa, Mr. E. Colborne Baber related in the Royal Geographical Society: "A party of English officers from a man-of-war landed on the island, and, meeting a company of natives armed with matchlocks, challenged them to a trial of skill in shooting. Affixing a mark to a tree about a hundred yards distant, the officers made what they considered pretty fair practice, without, however, astonishing the natives, who, when it came their turn to fire, disappeared into the jungle like one man, and crawled on their bellies through the undergrowth to about three yards from the target, which, of course, they all hit exactly in the center. When the Englishmen protested that such a method of conducting the competition was hardly fair, the natives replied, 'We do not understand what you mean by fair, but, anyhow, that is the way we shoot Chinamen.'"

Emigration from the Old World.—The migrations of European population, says "The Spectator," were never so general, so extensive, and so complex as they are at present. By reason of railways and the cheapening of travel, movements that in any former age would have occupied years are now accomplished in a twelvemonth. The greatest wanderers are perhaps Italians, for the struggle for existence is keener in Italy than in any other European land; the working-classes there have to labor more hours and for less pay than anywhere else. The natural result is an enormous migration of Italian artisans and laborers into neighboring countries; and with them neither Germans, Austrians, nor Swiss can compete. "They are better skilled in their calling and more sober in their habits; and, though they begin by working for lower pay, many of them earn, because they deserve, higher wages than their native competitors. They excel in all sorts of stonework; and at Z—rich and some other places architects are in the habit of stipulating that none but Italian masons shall be employed on a job. They built the St. Gothard Railway. They are found as far north as Dresden and Berlin, and the greater part of the engineering work in France is performed by Italian navvies. The Germans, Austrians, and Swiss, displaced by the Italians, push north and west. Many come to England, more go to the United States. . . . It is found in Austria that emigration is most rife in districts where two races are in conflict, and that those most prone to emigrate are of the German race. This is especially the case in Bohemia and Moravia, where the Slav and Teutonic elements are struggling for supremacy; in the north of Hungary, where the Germans have the upper hand; and in Galicia, where the population is Polish and German, and the Jewish element is being increased by immigration from Russia. It would, however, be unsafe to lay down any general law on the subject." It is not probable, for instance, that the Germans emigrate because they are worsted in the struggle for existence, but perhaps because they are more enterprising and farseeing than their Slavic neighbors and are better able to go. In some instances, the emigration is by masses, as in the district of Wisowitz, in Moravia, which has lost nearly half its population, and in the regions of Tabor and Kuttenberg, where "a veritable emigration fever has prevailed." Austria is making a use of the wandering disposition of its discontented subjects somewhat to its own advantage, by inducing them to colonize in the annexed district of Bosnia.

The Mystery of Eels.—Naturalists are generally agreed that at least three distinct sorts of eels are indigenous to British waters: the silver-bellied or sharp-nosed eel—the one that migrates in the fall—a firm, fine-flavored fish, with an almost black back, a silvery belly, and a fine, sharp head; the grig or snig, a yellowish eel, with a projecting under jaw; and the broad-nosed eel, an uglier-looking animal with a broader head, fierce and voracious in its habits, and of base tastes. To these a Norfolk fisherman adds a fourth, the "hooking" eel or "gloat," of blackish color and medium size, which is taken by anglers and habbers and on night-lines, and does not migrate. The annual migration seaward of the sharp-nosed eels gives rise to the valuable eel-fisheries of the English rivers, in which the fish are intercepted by wicker traps or eel-sets placed across the river, and in one of which 70,000 have been caught in one night. The moving of the fish is done in the night and always in a dark night; and it is liable to be interrupted by a change of wind, a clap of thunder, or a clearing away of the clouds. What becomes of the immense numbers of eels that descend to the sea every season has never been found out. They are hardly missed from the haunts they have left; yet no one has ever seen any of them returning. In the spring, however, the young eels come up the rivers by millions, keeping close to the banks and swimming in almost solid columns. They will surmount almost any obstacle, creeping wherever there is any moisture, through grass, and over stones and timber. These "eel-fairs" last through several days; and the tiny elvers, about as large as darning-needle?, used to be scooped out by the bucketful and applied to the land for manure, baked into cakes for men, or used as food for pigs, until an act was passed prohibiting their destruction. The fact that eels that have once gone down the rivers never return is asserted positively by all who have observed them. The question is then in order, How is the supply in the rivers kept up; and how is it that the eels found in the rivers are of a large size? The answer is, that young eels are produced in the rivers, and that eels are so numerous that, although immense numbers leave the rivers every year, yet equally immense numbers remain. The migrations have been generally supposed to be for breeding-purposes; but there are reasons for believing that breeding takes place in the rivers as well as in the sea, so that this alone can not explain them; and it has been suggested that they are a kind of swarming, like that of bees, impelled by excess of numbers. Naturalists affirm that the eel is an oviparous animal, and that it deposits its spawn as other fish do, and point to the presence of spawn and milt in it as revealed by the microscope; but the eel-fishers and eel-setters declare that it is viviparous; "that they have constantly opened eels in February which have been full of minute living eels (not parasites), and that in a tub of eels young ones have been found in the morning that were not there overnight. . . . To use their own words, there are thousands and thousands of eel-fry all alive in the bodies of eels cut open in February."

Dangers from Industrial Dusts.—A paper was read by Dr. Henri Napias before the Congress of Industrial Hygiene, held at Rouen in July, 1884, on the dusts developed in industries and the methods of guarding against injury from them. Dusts in the air call for especial consideration, from the fact that, besides vitiating the atmosphere in the way that gaseous impurities also do, they exert a mechanical action when brought in contact with the respiratory and digestive system. Even when they are wholly without toxic or essentially irritant effects, they are foreign bodies and obstructive, and are always in danger of exerting a traumatic action or causing abrasions. They are, therefore, all dangerous, while the dangers arising from them may be various in character. Mineral dusts, whether of stones or of metals, are the most dangerous, because, besides being hard and sharp and liable to cut the tissues, very many of them are also poisonous or caustic. Dusts of organic origin are less dangerous, but they vitiate the air, communicate unpleasant qualities to it if they are of an animal nature, and are frequently vehicles for the conveyance of infectious germs. Various inconvenient affections of the lungs are caused by breathing these dusts, among which may be counted phthisis, not as produced directly by them, but as often ultimately induced by the abrasions or deterioration of the tissues which they immediately occasion. The readiest and most available means of removing dusts is by ventilation, and, when this can be so directed as to take them away as soon as they are formed, it is almost sovereign. It will not do, however, to rely upon general ventilation, for that will at most remove the dusts but imperfectly, while its usual operation will be more likely to distribute them more widely among the operatives. The remedy should be applied to light dusts by means of chimneys or draught-flues; and to the heavier ones by means of blasts to drive them away. In cases where the dust itself is the object of the manufacture, or is to be applied in the manufacture, the remedy is to conduct the processes in closed apparatus. When either method is practicable, the dust may be kept down or removed by water, or the articles may be worked in a moist condition. Some workmen employ masks or respirators as means of individual protection, and they may in some processes be the only efficient means available. They are liable to the objection that they are always cumbrous and inconvenient; and frequently the workmen will become careless about them, or refuse to be bothered with them, and will leave them off. They should not be depended upon when any practicable means of keeping down or removing the dust can be employed.

Gambling at Monte Carlo.—Dr. J. H. Bennett gives in the "Pall Mall Gazette" some impressive illustrations of the enormous influence for evil of the gambling establishment at Monte Carlo, Monaco. The extent of it may be best understood by a simple calculation which the author owes to a professional gambler. The chances of the table are one in thirty-six in favor of the bank, and its annual gains, after all its expenses are paid, are $3,500,000. Hence $126,000,000—and thirty-six times its expenses in addition—have to be staked in it, won and lost, every year. "It is this fact of the gambler dealing with large masses of money that partly accounts for the strange fascination exercised by gambling. A careful player, who begins with, say, a thousand pounds capital, may have fingered, according to the doctrine of chances, thirty-six thousand pounds before he loses his capital. If he play long enough, the bank royalty of one in thirty-six is sure to swallow up his capital; and then he has had all the emotion of having been alternately successful or the reverse, rich or poor. He regrets when he has at last lost his initial capital that he did not stop when successful, which he never does, vows that he will be more prudent next time, and, in order to have the chance, sells, borrows, raises money anyhow." These facts destroy the argument brought forward by the patrons of the public tables, that playing at them is more straightforward and fairer than private club gambling, and that, as long as the latter is allowed, the former should not be interfered with. "At a public gaming table the bank royalty must inevitably ruin all who play constantly long enough to have risked their capital thirty-six times, even if the playing is carried on honestly, if such a term can be used. . . . Regular gamblers find this out in the long run, and learn to avoid the public establishment," resorting to the gaming clubs or forming them; and this is the explanation of the brood of gambling clubs, casinos, etc., which rise up, as at Nice, in proximity with the public gambling establishment. "They proceed from it, are created by it, would not exist without it. . . . When I first inhabited the Riviera" (in 1859), continues Dr. Bennett, "the Monaco gambling house was a mere gambling club or casino, which excited but little notice. Now it has become the great attraction, the great fact. Half the people one meets are going or have been to Monte Carlo."

"Anti-fouling" Paint for Ships.—Because iron and steel are peculiarly liable to corrosion when immersed in salt-water, vessels made of them require special protection. This can be given by covering the metal with some alkaline or basic substance, or the oxide of some metal electro-positive to it. Caustic lime and soda are very efficient for this purpose, and act equally well when made into a paint with oil. But their efficiency is destroyed when they cease to be caustic, or when they are saturated with carbonic acid, which they absorb freely from the air. Magnesia is equally efficient, and does not absorb carbonic acid. It therefore makes as good a material for a paint as could be desired, and, moreover, forms an excellent basis on which to lay an anti-fouling paint, which it protects from the galvanic action of the iron by isolating it, while it does not affect its anti-fouling qualities. Without the protection thus afforded, the iron not only effects the decomposition of the anti-fouling paint, but it also by contact takes away the anti-fouling qualities of that part of the paint which it does not decompose. All of the best anti-fouling paints depend for their efficacy on some compound of mercury or copper, while the action of iron is very strong in contact with both these metals; hence perfect isolation of the paint from the iron is necessary to make them of any value. Besides paints of magnesia and alumina, spirit and benzoline varnishes, powdered coke, anthracite or coal, lime, cement, and various kinds of silicates, mixed or suspended in oils, have been found good in greater or less degrees for these purposes. Zinc oxide also has some slight merits, while red lead paint, which has been used, is "out of the question. It is bound to give out after a certain time; and, besides, the metal beneath is corroded."

The Teak-Tree and its Timber.—The teak-tree is found growing in various places in the East Indies, through a region reaching from the eighth degree of south latitude in Java to about the Tropic of Cancer, and of undefined extent in longitude, but not farther west than 72° east. Its vertical habitat is about 3,000 feet above the level of the sea, but seldom below 2,000 feet. Its northern limit is in Bundelcund, where it is found in specimens not tall, at elevations rising as high as 4,000 feet. It grows in groups, a circumstance which is very convenient in trade. The wood is held in the highest esteem by ship-builders, and is preferred to any other for the backing of ironclad vessels. It shrinks hardly any, is considered the strongest and most durable timber of India, or perhaps of the world, and resists the attacks of white ants. The qualities of the timber vary greatly according to the character of the soil on which it grows, sometimes so much as to induce the belief in different species; but close examination has shown that, though varieties may exist, there is but one species. In Java, the Government have control of 1,650,000 acres of teak, besides new plantations. The planting and raising the trees, and mode of felling, classing, and measuring the timber are carefully regulated. Forest reserves of considerable extent exist in various parts of India, from some of which specimens have been shown more than 100 feet lorn', and 93 and 100 inches in circumference at the base. One of the chief sources of supply is British Burmah, where the total area of the reserve forests is 3,274 square miles, and 836 square miles were added during 1881-82. Nineteen thousand teak-trees were girdled, and 130,000 tons or 6,500,000 cubic feet of the timber were exported during this year from Rangoon and Maulmain. The principal forests are near the Irrawaddy River, where water conveyance is easy and ship-building is prosperous. A very fine plantation has been established at Nilambur, on the river Beypore, in Malabar, where 100 acres are planted each year, and there are now about 1,800,000 trees. An increasing source of supply is also being developed in Siam. According to Colonel Beddome, the growth of teak is very rapid, compared to that of the oak. The growth in the sapling state may be calculated at about one or two cubic feet a year; but after thirty years it is immensely accelerated, and an increase of five cubic feet has sometimes been remarked in a year. Several other trees, but little known as yet, are mentioned as nearly equal in value to the teak. The takieng, besides being a rival to it in size and quality, possesses the advantage of being easily bent by artificial means. Sir Robert Schomburgk saw a log of it measuring 135 feet, perfectly sound, in the building-sheds of the King of Siam. The red peema of Burmah and Tenasserim is considered equally useful with teak, as is also the touk-kyan, with its dark-brown wood. Angely is well suited for the floors and bottom-planking of ships, but has to be used with copper, as it corrodes iron. Jackwood, a tree of the same family (Artocarpus), furnishes an excellent fancy and furniture wood, and is admirably adapted for boat-building. An Australian timber called tuart is believed by Mr. Simpson to be superior to all others for the backing of armor-plated vessels, as it can not be split by any possible means.—From a paper read by Mr. P. L. Simmons before the Society of Arts.

The Duk-duk.—According to Mr. Wilfred Powell's "Among the Cannibals of New Britain," affairs in the Duke of York Islands are regulated by an officer called the duk-duk, who appears to combine in himself the functions of judge, police officer, and executioner. He is distinguished by his peculiar dress, and by his helmet, which, reaching down to his shoulders, quite conceals his face. It is made of basketwork, so that the wearer can breathe freely, and is painted in front as a terrible face. When any person is accused by his neighbor or otherwise blamed, he must pay the duk-duk a sum of money as damage, and this officer goes in person to the house of the accused to see that all is made right. If the accused will not settle, his house is burned or he is speared. Women and children dare not look at the duk-duk, for fear they will die on the spot, and therefore run away and hide, whenever they know, from the peculiar cry he utters to give notice of his approach, that he is coming. Men may be initiated into the mystery of this office when they reach a certain age, on payment of a prescribed sum, and, if they do not do this, they must keep out of the way of the duk-duk. The initiated must never speak of the secrets of the mystery out of the spot that is consecrated to it, and the uninitiated must not go to that spot.

Temperature of the Glacial Period.—Some geologists hold that the glacial phenomena were the result of warmer, not of colder, conditions of climate than now exist. Their views are briefly summarized by M. Millot, of the scientific faculty of Nancy, France. For the production of glaciers in temperate latitudes an active evaporation at the equator, to furnish moisture to be condensed into snow on the mountains, is above all things necessary. Thus, the quantity of ice produced will be within certain limits proportioned to the heat received at the equator. No heat, no evaporation; no snow, no glaciers; on the other hand, there will be no glaciers if it is too hot for the snow to be deposited on the mountain-tops. This was probably the case before the glaciers appeared. Then, as the heat of the sun gradually diminished, as it is supposed to be doing regularly, the glaciers begun on the mountains, small, but growing, for the evaporation at the equator was still infinitely greater than it is now. So it may have continued for ages, the snow condensing on the mountain-tops, and the sun lifting up immense quantities of water to be condensed. This was a period of maximum favorable conditions for glaciation. Then, the sun still cooling, the amount of evaporation fell off, till it ceased to afford the excessive supply, and the glaciers became stationary, then retrograde till they were reduced to the relatively insignificant proportions in which they now appear. This theory explains the deposition of glacial moraines in the midst of tree-ferns and a Mediterranean vegetation; for, while the glaciers were extensive in consequence of the immense precipitation everywhere but immediately upon them, a warmer climate prevailed than is now enjoyed in the same regions. This theory explains also how Arctic animals, finding suitable conditions of existence in the glaciated districts, came to be mixed up, as is shown by their remains, with the herbivorous animals of milder climates, which were separated from them only by a line. This theory, unlike all other theories of the glacial period, does not require the supposition of any interruption of the regular, normal order of climatic development and events.

Arts and Customs in New Guinea.—Mr. Coutts Trotter, in an address before the Royal Geographical Society, stated that while the people of New Guinea are still in the "Stone age," their artistic faculty is strongly marked, especially among the western tribes. This is shown conspicuously in the carved ornamentation of their canoes, houses, implements, and weapons. Their tastes are further seen in the habit of adorning themselves with flowers and leaves—of crotons, dracænas, coleus, begonias, scarlet hibiscus, and the anise scented clausena. They are also alive to the advantages of trade, the tribes on the western coast having for centuries been exchanging the varied products of the country with the Malays, Bughis, Chinese, and others, for cotton cloths, iron and copper wares, knives, beads, mirrors, indigo, and arrack. In conducting their inland trade among themselves, they assume that inter-tribal war is the normal condition of man, and adopt ingenious devices to mitigate inconveniences. But even the plan of setting apart for each hill-tribe its allotted station on the coast is not always sovereign for the avoidance of collisions. The people of the southeast peninsula make long voyages to the west of the Gulf of Papua for sago, in strange craft composed of several canoes lashed together, with a house at each end. Each village or district often has its trade-specialty, as, for example, for pottery, or for canoes, or shell or other ornaments. Salt is in great demand, especially in the interior, whither sea-water is sometimes carried in hollowed bamboos; or salt is obtained by burning the roots of trees which have grown in the salt water. The people in most parts are skilled agriculturists, and grow, generally with the help of artificial irrigation, all the usual plants of tropical Pacific culture, most of which—with probably the traditions of scientific agriculture—seem to be of Asiatic origin. Any one may clear and cultivate a piece of land within the territory of his tribe, but they have a strong sense of proprietorship, even of the fruit-trees in the forest, and of the fish in their own streams, or their own tract of coast. The social and political organization of the people is quite rudimentary. The chiefs have but little power. Important matters are settled by the assembly, and, otherwise, every man, beyond conforming to certain established customs, is a law to himself.

How to live One Hundred Tears.—How to live a century and grow old gracefully are discussed in a pamphlet under that title recently published by Dr. J. M. Peebles, who appears to have faith in the practicability of both his propositions. Success depends upon many elements, among the most tangible of which are air, sleep, food and drinks, and clothing. We must breathe pure air, and breathe deeply; not be afraid of night-air, and get as much of our air out of-doors as we can. As to sleep, "I say," says Dr. Peebles, "to my friends and patients, 'get up; get up at five o'clock in the morning'; and I set them the example. If they want more sleep I say, ' take it; take all you want; take eight hours; take nine hours; take ten hours, if you choose; but take them in the early hours of night rather than by daylight. Don't insult Nature.' If you get angry, take a bath and go to bed and sleep; if the world abuses you, take extra sleep; if you are dyspeptic and discontented, take a long, sound sleep, and, waking, you will find that all the world is smiling." For diet, the vegetarian and farinaceous system is recommended. For drink, water, which should also be applied freely and frequently outside, while intoxicating liquors, tea, coffee, etc., are best left alone. The clothing should always be arranged with a view to protection against variations of heat and cold, and with no other, and should not be allowed to impede any of the functions or movements of the body. Dr. Peebles thinks that there may be good in medicines, notwithstanding all that is urged against their use by many writers on hygiene, and says: "If there were no pre-natal weaknesses, no transmitted blood-poisons or hereditary tendencies; if there were no sudden climatic changes; if there were no violations of the physical, mental, and moral laws of God, medicines would be quite unnecessary. But, as rational, practical men, we must take human beings precisely as we find them; and we find many of them wretchedly begotten, badly cared for in infancy, unwisely trained in childhood, wickedly tempted in youth, and in manhood frequently exposed to winds, pelting storms, and the low malarial lands of the Western prairies. Thus conditioned, human ills, aches and pains and diseases are absolutely unavoidable, and accordingly remedies medicinal remedies carefully selected and wisely administered, are positive necessities." Finally: "Exercise charity toward all, control your passions, govern your appetites. Develop and manifest a sweet and peaceful spirit. Carefully observe the rules of health; . . . and, with a fair constitution to start with on the journey of life, you may easily live a full century."

Do Insulated Conductors attract Lightning?—A house in Neufchâtel, Switzerland, was struck by lightning and burned last summer; and it was suggested that the electric stroke had been invited by a lot of old iron that was stored in the attic. M. Calladon, speaking in the French Academy of Sciences of this suggestion, remarked that the mere presence of metal, without communication with the earth, could not have any material influence in attracting the lightning from the clouds; if it had, then the houses with tin roofs, many of them without lightning-rods, now so common, would be in great danger, whereas they are not struck oftener than houses with tile roofs. The presence of iron, however, might increase the danger of fire after the house had been struck; for, if we place a combustible substance between two conducting surfaces, it is generally sure to take fire when an electric current is passed through it from one of the conducting surfaces to the other. So, if lightning should strike a house, it would find its way to any masses of metal within the building and ignite whatever combustible matters it passed. In view of this fact, and of the present very extensive use of metal in house-construction, the provision of suitable conductors to divert electrical currents from the combustible parts of the building has become more important than ever.

Was it Volcanic or Cosmic Dust?—Mr. W. Mattieu Williams is of the opinion that the long continuance of the glowing twilights tells against the validity of the volcanic-dust theory; for that dust must have settled by this time, or, if so much of it has continued to float in the atmosphere, it should have shown its presence more palpably than it has done. The two alternative hypotheses to this one, worthy of serious consideration, are: 1. That the earth, and possibly the whole or a large portion of the solar system, has, in the course of its journey through space, passed through a region unusually rich in meteoric dust; or, 2. That an unusually large amount of aqueous vapor has been raised to the upper regions of our atmosphere by increased solar activity. Apparently in favor of the meteoric theory is the statement of F. Mangini, that on three days in February and March, 1885, when the glows, accompanied by rain, were especially remarkable, he collected at Reggio, in Calabria, some new-fallen red dust, which, when examined under the microscope, seemed to consist of mica, quartz, and irregular polyhedric crystals. Analysis brought out magnetic iron oxide, sulphuric and phosphoric acids, silica, calcium, magnesium, aluminum, nickel, and arsenious, ferric, and manganous oxides. The dust did not come from Etna, because the wind was blowing in the opposite direction, and Etna dusts are black; nor from the Sahara, because Sahara dusts contain no iron.

Oranges in Palestine.—The climate and soil of Palestine are well adapted to the cultivation of the orange, which, according to Consul Merrill, there suffers from no diseases or parasites of any kind. The trees appear to flourish best near the sea, and the orange-groves are for the most part near Jaffa and Gaza. In Jaffa there are five hundred gardens, of which one hundred and fifty are ranked as first class, all the gardens together containing about 800,000 trees. The trees are set about fifteen feet apart, while the ground between them is planted with small fruits or vegetables. The sweet lemon is used as the stock, and the variety of orange desired is grafted upon it. The trees are watered every week in the summer, at a cost per season of about one fifth the value of the crop in gardens of the first class. The Jaffa oranges proper, the only kind exported, are oval, or lemon-shaped.