Kitabı oku: «Birds and All Nature Vol VII, No. 1, January 1900», sayfa 6
THE YOUNG NATURALIST
DIAMONDS AND GOLD
CECIL RHODES says: "So long as women are vain and men foolish there will be no diminution in the demand for diamonds." He ought to know, for he is called the "Diamond King."
Thirty years ago John O'Reilly found some children at a farm house in South Africa playing in the evening with some beautiful stones that had peculiar forms and brilliancy. He took the finest to town with him and found it was worth $500.
People swarmed into the country where little children had rough diamonds for playthings, and over $400,000,000 worth of these crystals has been taken from Africa.
While the diamond excitement was still raging the people were inflamed at finding there was gold about them in great quantities. The diamond hunters in many instances became gold diggers, because there was even more money to be made in gold digging than in hunting for diamonds.
Last year nearly $75,000,000 worth of gold was produced in that country. That is more than we produced in the great gold fields of the United States all taken together. We crushed from the rocks and dug out of the dirt about $65,000,000 in gold. The famous gold fields of Australia yielded about the same amount as our own country.
So much wealth in Africa has embittered the people. The Dutch farmers, called boers, occupy the heart of the best country. They are not progressive, the English say. Perhaps they mean that the boers do not move away fast enough to suit the English. They have made trek after trek to get out of the way of the English. Trek means journey. But when they realized how much wealth there was about them in the country which they had thought was so poor, they decided not to make any more treks to let the British in.
These Dutch farmers withstood the English at Majuba Hill, Jan. 28, 1881, and killed off nearly all the British forces sent against them. In this fight they lost but fourteen men in killed and wounded, while wiping out their enemies. They celebrate this day as we do the Fourth of July. It is their day of independence, and they do not wish to give up the advantage it gave them. Sixty years ago less than five hundred boers under Andries Pretorius defeated twelve thousand Zulus, killing three thousand of them.
As the Dutch have such a good reason for trusting to their weapons there is little wonder that the gold and the diamonds of the country brought them into a war with England.
LIQUID AIR
MANY substances have three forms – solid, liquid, and gaseous. It takes cold to change a gas to a liquid, and more cold to reduce the liquid to a solid. Steam, water, and ice are good examples.
Air is a substance that requires so much cold to reduce it even to a liquid state that we know nothing of it as a solid. Our Smithsonian Institution gave Professor Dewar of the Royal Institute of London a gold medal for his discovery in regard to reducing it to a liquid.
No artificial cold is intense enough to affect air except when it is confined under great pressure. When a gas is compressed and made cold it tends to liquefy. But it takes enormous pressure and intense cold to make liquid air.
It is a grayish substance that may be carried about like water. It has a tendency to steam up, and when its vapor comes into contact with flesh a cooling sensation is produced. But living flesh cannot long remain in contact with the liquid itself. It produces a wound much like a burn.
By careful use of liquid air in surgery, the flesh may be so put to sleep that the surgeon's knife is not felt by the patient as he watches the cutting. A cancer has been cut out by liquid air in a sort of burning process that needed no knife. Cremation has been accomplished by its use.
Cremation is burning. Burning is the union of oxygen with the substance consumed. Liquid air left exposed to common air evaporates and sends out its nitrogen so that almost pure liquid oxygen is left in the vessel. This placed in contact with the body to be consumed soon sends all except its mineral parts flying away in the atmosphere in a vapor thinner than smoke.
It is the coldest substance known. It takes an intense cold to produce it, and it has to remain cold much as ice is cold, only very much more so, as long as it is liquid air. For this reason it is carried about in vessels constructed so as to exclude the heat. Mercury dropped into it becomes a solid block, and meat quickly freezes so hard that it is brittle as glass and may be broken into a thousand pieces.
The liquid oxygen left after exposure of liquid air may be placed in a hollow in a cake of ice. Dip into it a watch spring and touch a lighted match to it and you will see the steel spring burn as if it were full of pitch.
Eight hundred gallons of common air are compressed into one gallon of the liquid. The liquid is unattractive and very common-looking. You would not suspect its great powers by merely looking at it in a dish. But when it expands into common air it has tremendous energy. A few drops confined in a closed iron pipe will explode and blow the metal to atoms.
When first produced it was so expensive a product that its value was above that of rubies. Now it is cheap and becoming more so. We expect it to become an ordinary article of commerce. One company is capitalized at $10,000,000 to push its use in place of steam and electricity.
Probably some of the companies advertising shares to sell are putting its powers far too high. One company's agents are representing that a very little of it in a cup will keep an icebox cold all day, and that a pound of it will reduce the heat in a large house on a warm summer day so that it may be kept cool at very small expense.
These extravagant claims are probably made for the purpose of deceiving people so they will buy shares. The facts seem to show that a pint of liquid air will not cool an ice box much more than will a pound of ice. The effect of a gallon of it in a large house would scarcely be felt in July, except for a short time in one or two rooms.
COMMON MINERALS AND VALUABLE ORES
II. – QUARTZ AND THE SILICATES
THEO. F. BROOKINS, B.S
Principal Au Sable Academy, N. Y
COMPARATIVELY few persons associate the gem opal, with its brilliant internal colored reflections, with that material forming so large a part of the soil, sand. Yet the two are almost identical in composition. The mineral constituent of sand and of opal is quartz, though the latter often contains in addition some water.
Quartz is composed of the two elements occurring the most abundantly in the earth's crust, silicon and oxygen, both non-metals. As already indicated, the most common representative of the mineral substance is the sand of the soil. The sand grains are generally so eroded by the atmosphere and surface waters as to show little of the true quartz structure. A typical specimen of quartz, commonly known as "rock crystal," clear, transparent and approximately perfect in form, is not difficult to obtain for study. If not occurring in the particular locality it may be obtained from a dealer in minerals at slight expense. As studied by means of the rock crystal, quartz is remarkable for its transparency, its regular crystal form, and its great degree of hardness. Its transparency is such that printing may be read through the crystal. Its crystalline form affords an unfailing means to the mineralogist of recognizing the substance as quartz. If our specimen be large and perfect, we note that it is bounded by planes in such manner that we have a hexagonal prism terminated at either end by a hexagonal pyramid. With convenient apparatus for measurement, we learn the all-important fact to the mineralogist, that the angle between any prism face and an adjacent pyramid face is 141° 47´. The mineralogist obtains his accurate measurements by means of an instrument known as the goniometer. We may obtain cruder results by bending a readily flexible wire over the two faces, perpendicular to the edge of their intersection, until it is tight against either face. Then placing one arm of the bent wire along the base of a protractor, the point of flexure at the center of the base, the number of degrees between the two arms may be read, thus giving roughly the angle between the prism and pyramid faces of the quartz crystal. The great hardness of quartz is apparent in that it cannot be scratched with the point of a knife and that it will cut glass. Often clear parts of quartz crystals occur studding the surface of a rock structure, in the form known as a crystal aggregate. One property of quartz rock (any sandstone or quartzite) we must not fail to notice is the irregular fracture. This is recognized in the statement that quartz has no cleavage.
The study of the rock crystal should not lead us into the false conclusion that quartz is commonly transparent. Instead it occurs in various shades and colors from smoky white through yellow, red, purple, and brown to black. The cause of the abundance of sand on the soil surface is also liable to misinterpretation. While sand is naturally of great abundance, yet its commonness at the surface of the soil is due largely to its great resistant powers to the agencies of weathering.
Quartz has an economic value directly in glass sand and of course as a soil constituent. In the latter capacity, it is taken up by many plants, and is the silica that studs the saw edges of the blades of sedges and grasses. The precious stones, agate, amethyst, and jasper are varieties of quartz.
The silicon that is so important a constituent of quartz, composes with aluminum a large part of various minerals comprised under the name feldspar. This substance is slightly less hard than quartz and has many variations in color; but, unlike quartz, shows regular cleavage faces. Feldspar is always crystalline, but good crystals are not common. It is very difficultly soluble, yet readily yields to the influence of weathering. A feldspathic rock hence readily crumbles. During the process of disintegration, the feldspar may change from a clear, hard, glassy mineral to a dull, opaque substance. This product of disintegration is our common white clay. With quartz, then, feldspar is of great importance in the forming of soil.
Allied to the feldspar group of minerals as regards cleavage, and yet of far different special characteristics is the class of substances known as mica. How many of us ever think of the so-called isinglass of our stove doors as a mineral substance? Yet transparent mica, muscovite, is the source of that household convenience. A study of the specimens of mica in our stove door will provide abundant ideas of the nature of mica. We have often noticed how, under the influence of excessive heat, the isinglass splits into thin sheets, thus showing the cleavage of the mineral. These plates of mica are of especial value in giving cleavage to rocks which would otherwise fracture irregularly. The cleavage of slates and of the common shale rocks is due to the presence of mica particles which have, at some period in the history of the earth's crust, through the action of heat and pressure, been arranged along definite planes. Isinglass represents the transparent variety of mica. Other varieties are brown and even black, owing to the presence of traces of potassium, magnesium, iron, etc., in varying degree. Some micas do not easily decay, and so we frequently see glittering particles among the fine grains of soil and the sands of beaches.
The minerals already mentioned, quartz, feldspar, and mica, are the components of a large part of our granites. In the case of the red Scotch granite, another silicate, hornblende, replaces the mica. Various silicates of economic value are asbestos, a variety of hornblende, and augite, which are silicates of magnesium and iron or calcium; and talc, which is a silicate of magnesium containing water. A great number of gems are found among the silicates, including tourmaline, garnet, topaz, beryl, and chrysolite.
THE DANGER FROM THE IMPORTATION OF ANIMALS
AN abstract of J. S. Palmer's essay on "The Danger of Introducing Noxious Animals and Birds" appears in Our Animal Friends. There are several societies in this country for the express purpose of purchasing and importing European birds. One society in Cincinnati has contributed $9,000 to this object, and other cities have raised considerable sums. Our contemporary thinks it would be well that all such experiments should be made under the sanction of government experts of the Department or Agriculture. In addition to voluntary importations, it often happens that animals are unintentionally brought into the country, as trading-vessels have carried the European house mouse all over the globe, and the introduction of rabbits into Australia is perhaps the most striking example of the dangers of unconsidered importations. They were introduced for purposes of sport, and were liberated near Melbourne in 1864. Within twelve years they had spread over the country and become a veritable plague, and millions of dollars have been spent for bounties, poisons, and other methods of destruction. Thousands of miles of rabbit-proof fences have been built, and in 1887 no less than 19,182,539 rabbits were destroyed in New South Wales alone, and the rabbits seem to be on the increase. The little Indian mongoose was imported into Jamaica to cope with a plague of rats and proved most effective, but after it had destroyed the rats it turned its attention to the domestic animals and poultry, so that the islanders would now be glad if they could get rid of the pests. Such are a few examples of the danger of disturbing nature's balance.
THE AMERICAN BISON
A REMARKABLE article recently appeared in the Scientific American, written by Prof. Chas. F. Holder, entitled, "A Crime of a Century," in which is described the extermination, the wiping out of the American bison.
"In 1870, and later," said an army officer, "the plains were alive with bison, and in crossing at places I had difficulty in avoiding them, so vast were the herds. If anyone had told me then that in twenty or thirty years they would have become almost entirely extinct I should have regarded the statement as that of an insane person."
We are able to corroborate this statement. In August, 1869, while crossing the Kansas plains in a stagecoach we had the privilege, as we regard it now, of seeing one of the largest herds of buffalo then remaining. When first seen, at a distance of from three to five miles, we could distinctly hear the roaring of the animals, who had been stampeded, perhaps by hunters, who were at that time wantonly destroying the grand creatures for their robes. That so many of these animals could have been killed in mere wantonness, says Prof. Holder, seems incredible when their vast numbers are realized. We first hear of the bison from Cortez and his followers in 1521. Montezuma had one in a zoölogical garden, the specimen, in all probability, having been caught in Coahuila. In 153 °Cabeza saw them in Texas, and in 1542 Coronado found a herd in what is now the Indian Territory, one of his officers describing them as horrible beasts that demoralized the horses. In 1612 Sir Samuel Argall observed herds of bison near the national capital, and, it is said, two hundred and eighty-seven years ago herds of bison grazed on the site of the capitol building at Washington. In 1678 Father Hennepin observed them in what is now northern Illinois, and in October, 1729, Col. W. Bird saw herds in North Carolina and Virginia. It is known, in fact, that the bison formerly ranged in millions from the Atlantic seaboard to the Gulf of Mexico, from Texas to the Great Slave Lake, and as far west as central Nevada. "As to their numbers, they were like the sands of the seashore, and the accounts given by those who hunted them twenty or thirty years ago to-day seem like vagaries of a disordered imagination." Colonel Dodge, in his memoirs, states that on one occasion he rode twenty-five miles in Arkansas, always being in a herd of buffaloes, or many small herds, with but a small separating strip between them. The animals paid but little attention to him, merely moving slowly out of the way or advancing, bringing the whole herd of thousands down on him with the roar of an avalanche. This he met by standing fast and firing when they came within short range, the shot causing them to divide. This he did as a protection, otherwise they would have run him down and crushed man, horses, and wagon. This herd was later found to be fifty miles wide and to occupy five days in passing a given point on its way north. It was estimated that the herd comprised half a million buffaloes. A train on the Kansas Pacific road in that state in 1868 passed between the towns of Ellsworth and Sheridan – one hundred and twenty miles – through a continuous herd of buffaloes. They were packed so that the earth was black, and more than once the train was stopped, the surging mass becoming a menace to human safety. This is the same herd first seen by us in August, 1869, and again in 1871 and 1872. An army officer relates that he was at that time on duty in the pay department, which made it necessary for him to travel on the Atchison, Topeka & Santa Fe railroad. One day the train entered a large herd, which scattered and seemed to go wild at the shrieking of the whistle and the ringing of the bell. As the train went on the thicker they became, until the very earth appeared to be a rolling mass of humps as far as the eye could see. Suddenly some of the animals nearest turned and charged; others fell in behind, and down upon the train they came like an avalanche. The engineer stopped the engine, let off steam and whistled to stop them, while the passengers fired from the platforms and windows with rifles and revolvers, but it was like trying to stay a tidal wave. On they came, the earth trembling, and plunged head down into the train. Some were wedged in between the cars, others beneath; and so great was the crush that they toppled three cars over and actually scrambled over them, one buffalo becoming bogged by having his legs caught in the window.
The question of interest to-day is how was it possible to destroy so many animals in so short a time and what methods were employed? Many were destroyed by stampeding over precipices. In 1867 two thousand buffaloes became entangled in the quicksands of the Platte river. At another time a herd was lost by breaking through the ice of Lac Qui Parle in Minnesota. The cold winters of the north killed many. But man was their greatest foe. He soon found that the buffaloes had a value. The Indians slaughtered them for their skins, bone and for food. The white man, however, killed for sport, for the hides and heads, and to provide the gangs of railroad men with meat. The animal at this time had a value estimated at $5, which was sufficient to attract an army of destroyers. One firm in New York between 1876 and 1884 paid for hides alone nearly $1,000,000. The government never interfered. The real extermination of the buffalo, in the opinion of Prof. Holder, was caused by the demands of trade, aided and abetted by sportsmen, Indians, and others; but the blame really lies with the government that in all these years permitted a few ignorant congressmen to block legislation in favor of the protection of the bison, so that all the efforts of humanitarians were defeated and the bills when passed pigeon holed.
The still hunter was the most insidious enemy of the buffalo, a single man, by sneaking upon a herd, having been known to kill one thousand in a single season. Capt. Jack Bridges, of Kansas, killed 1,142 buffaloes in six weeks. In the different states there were regular killing outfits that cost, in rifles, horses, carts, etc., from $2,000 to $5,000. Such methods developed some famous characters. Buffalo Bill (Col. W. F. Cody) was one. He contracted with the Kansas Pacific railroad to furnish them with all the buffalo the men could eat as the road was built; and, according to Mr. Cody's statement, they ate 4,280 buffaloes in eighteen months, for which he received $500 per month, "the price he paid for his title."
There were living at the last government census, made in 1891, 256 pure-blooded buffaloes in captivity, the last of the race.
A buffalo robe is now a scarce article and a well-preserved specimen brings a high price. Massive heads of old bull buffaloes are preserved in many museums and are valued at from $150 to $250.
Mark Twain once said that the most wonderful scene he had ever looked upon was an enormous herd of buffaloes in Colorado.
Mr. John D. Dunham, formerly United States land commissioner in Wyoming, and later connected with the Yellowstone Park commission, recently stated that there were between 120 and 140 buffaloes left in the United States last autumn, and the mortality among the surviving beasts was greater last winter than ever before during their captivity. Despite the severe penalty for killing the big animals in the National Park, a dozen or more buffaloes have been slain there every year. Last year a form of influenza destroyed some of them, and there are probably no more than fifty of the veterans of the plains left. Baker, in his "Wild Beasts and Their Ways," says: "The bison is a grand-looking creature, and in my opinion it is the most striking of all wild animals."
