Supposing these earth cracks develop more slowly, they may suck away the water without devastating explosions. Then the last man’s fate will be the worst describable. He will die of thirst. The scene of his death will probably be the great valley in the bed of the Atlantic Ocean, off the Brazilian coast, halfway between Rio Janeiro and the Cape, where now six miles of green water lie between the steamer’s keel and the abysmal slime beneath. There, hopelessly digging in the everdrying mud, he must perish, and leave his bones to parch on a waterless planet.
The antarctic polar ice cap has been growing thicker and heavier for uncounted ages. The distance from the south pole to the edge of this ice cap is 1,400 miles. The ice rises steadily from the edge to the center. At that center it cannot be less than twelve miles in thickness—twice as thick as Mount Everest is high. Southern latitudes are growing warmer, and this ice cap is known to be cracking. Suppose it splits. Imagine the gigantic mass of water and ice that will come sweeping up north over the oceans and continents of the earth! Where, then, will the last man breathe his final gasp? High up in the snows of some great range he will perish miserably of cold and starvation, looking down on a huge shallow sea, beneath whose tossing waters will lie the whole of the races of the world.
Or, last, and perhaps dreariest fate of all, the human race may outlive other mammals and last until the sun, as some day it must, grows dull and cold, and vegetation dies from the chilled earth. The miserable remnant of earth’s people must then slowly die out after ages of an existence to which that of the Eskimo of to-day is a paradise.
HOW CANTILEVER BRIDGES ARE CONSTRUCTED.
A cantilever bridge consists of two inverted trussed beams, each balanced on a pier, one part extending over the river and the other to the shore, where it is firmly anchored in solid, heavy masonry. The ends extending over the river toward each other from the opposite piers are joined by a short truss in such a manner as to permit expansion and contraction consequent on changes of temperature, and yet be proof against vertical or lateral pressure. Such a bridge, it is said, sustains scarcely any strain in the center of the span. Each half of the entire bridge is self-balanced on its pier; and when a long, heavy train is on it, the part of the train on one side of the pier is balanced as on a “teeter” by the part on the other side of the pier—in front or behind. The bridge across the Niagara River was the first of the cantilever kind ever constructed, and the one over the Hudson River was erected upon substantially the same principle, the cantilever being utilized as nearly as possible. In building the bridge it was important to obstruct the Hudson as little as possible, much opposition having been raised against it by those interested in the navigation of the river. Therefore a combination of anchorage trusses[{53}] and cantilever spans was adopted. The river is crossed in five spans, with four piers in the channel. On each of the two piers nearest the shore, four sets of steel rollers carry the ends of the anchorage trusses and of the cantilevers of the east and west spans. The bridge is made of steel. The cantilever principle is again introduced in the famous Forth Bridge. At a distance of six hundred and eighty feet from the ends of either approach viaduct are the north and south cantilever piers, with their great arms stretching out to and joining with the girder approaches. In the opposite direction the cantilever arms extend for six hundred and eighty feet toward Inchgarvie, and come within three hundred and fifty feet each of meeting the arms of the cantilever built on that island. This cantilever pier is founded in the bottom of the shallow water close to the west of the islet. The gaps of three hundred and fifty feet between the extremities of the cantilever arms and of the ends of their neighbors to the north and south are filled in by connecting or central girders of the hogback lattice pattern. The total length of each of the north and south cantilevers is one thousand five hundred and five feet, while that of the central one, owing to its having a longer foundation base, is one thousand six hundred and twenty feet. The two main spans measure each one thousand seven hundred and ten feet, with a clear headway above high water, for five hundred feet in the center of the span, of one hundred and fifty feet, while the half cantilever spans to the approach viaducts north and south are each of six hundred and eighty feet. The measurement from the extremity of one approach viaduct to the extremity of the other gives the distance taken up by the three double cantilevers and their connecting girders as five thousand three hundred and twenty feet, or just over a mile.
TRADE IN TRIFLES.
It takes about a billion and a half of eggs every year to supply the demand in Great Britain and Ireland, besides all the eggs that are produced there. Forty per cent of the eggs consumed in the United Kingdom are brought from twenty different foreign lands, including several of the British colonies.
Germany comes next to Great Britain as the largest consumer of eggs in Europe. Her imports are a little over a billion and a half a year, and she is obliged to pay £3,000,000 a year for the eggs she buys from other countries.
Japan is now using a great many eggs, though few are produced in the country. As they are very much cheaper in China, the eggs Japan uses are almost all imported from that country.
Russia is the largest exporter of eggs. The number sent from that country in 1896 was 1,475,000,000, of which 289,000,000 were shipped to the United Kingdom.