Page:Popular Science Monthly Volume 78.djvu/309

Rh We are all acquainted with the results of the labors of science in the fields of acetylene and electric lighting, where energy is furnished by water power or where cheap coal can be burned miles away from the dazzling lights. Every city has its object lesson. Only one instance will be spoken of.

The deficiencies of the carbon-filament incandescent electric light bulb are known to all of us—its reddish light, its decrease in brilliancy with use, its comparatively short life and rather low efficiency. Most of us can testify to the superiority of the tungsten bulb, one of the latest productions of the chemist and electrician—its white light, its long life with but slightly lessened intensity, the comparatively low cost of the light per candle power.

From a relatively slightly known substance—material for the mineralogist's collection—the use of tungsten has rapidly increased. Forty-six tons of its ore were mined in the United States in 1900; in 1907, 1,640 tons; truly, in comparison with iron, copper and lead, an insignificant amount. But when we remember that one pound will make thousands of electric-light filaments we can comprehend that revolutionary results may follow. The ore is widely distributed in the Rocky Mountains, as far north as Alaska, and no prophecy can be made as to when it may become exhausted.

Tungsten has many other uses possibly less known to you; among them, as a material for small crucibles to be used in the electric furnace, and as a modifier of the properties of steel, the latter probably the most valuable. Tool steel containing tungsten holds its temper at high temperatures. Tools with a tungsten content of 16 per cent, to 20 per cent, can be used with the lathe running at such a speed that the chips are blued from the heat yet the temper of the tool is not affected. That is, in consequence of the high speed, about five times as much work can be accomplished as when high carbon steels are used, one man's labor being thus multiplied by five. Here again the metallurgical chemist has shown himself equal to the demand upon him, a demand for a new means of decreasing the drain upon a part of our resources.

What about the forests? Personally I have no fear. Aside from the methods of scientific forestry, which must necessarily come, other forces are acting. Although the chemist uses forest products as a source of supply, he need not be feared. He can utilize the waste wood—the stumps, the chips, the branches, the sawdust, material fit for nothing else. And he is daily perfecting chemical products to take the place of wood. Cement is one of these; of this the amount is increasing and the cost diminishing. In 1908 we made in the United States 51,073,612 barrels of Portland cement at a cost of $43,547,679, an increase over the preceding year of over two and a quarter million barrels with a decrease in cost of more than ten million dollars. In 1909