Page:Popular Science Monthly Volume 78.djvu/308

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If the past achievements of science give us hope that it can stay the drain upon our resources, we can gain encouragement by examining its present activities.

While doubtless much fuel has been wasted it is now being used much more economically than formerly. There is a tendency to centralize the evolution of heat and other forms of energy produced from burning coal. A large proportion of our coal is used in locomotives for the purpose of hauling more coal to the place of consumption. This can be saved by carrying the energy from the coal fields as electricity or gas. Even the conversion of coal into producer gas at the place it is used is a great advantage. The lowest grades of coal are employed, such as lignite, slack and culm, and the gas gives several times as much energy under a boiler as would the coal from which it is made. Again, our culm piles, the accumulations of years, are being moulded at slight expense into briquettes which are in many respects superior to coal as a fuel.

As a substitute for our vanishing gasoline we are looking toward alcohol. Although at present it can not compete in price, new sources are being sought by the chemist and it will undoubtedly become cheaper. Not only can the crude material for its manufacture be obtained from the grains but working processes have been announced, starting from the cellulose of sawdust and peat.

I need only refer to the value of our water power. It has been estimated that the United States has about 40 million horse power which is now available and four times this which can be developed. To get an equal amount of energy from our steam plants would require over 3,000 million tons of coal. Or, to state it in another way, by developing this water power, now not utilized, over three thousand million tons of coal can be saved—about four times our annual consumption.

With a possibility of the disappearance of available petroleum and even of coal, substitutes for these have been ardently sought in recent years or, if not complete substitutes, attempts are being made to find something which will decrease their excessive use.

As we all know, the luminosity of illuminating gas is due to minute particles of carbon which are heated to incandescence. A substitution of other solid materials in the hotter, though non-luminous, flame of the Bunsen burner—lime, platinum and zirconium—met with failures. Then came a German chemist, Auer von Welsbach, and discovered, through extensive investigations with the oxides of the rare earths, that while neither thorium nor cerium oxides were highly luminous, if one per cent, of cerium oxide is added to thorium oxide the product glows at high temperatures with great intensity. The gas mantle and incandescent light were the result, and with them a far greater degree of illumination, with the use of a fraction of the gas formerly used.