298 THE POPULAR SCIENCE MONTHLY 



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 central- 

 ize 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 esti- 

 mated 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 incan- 

 descent light were the result, and with them a far greater degree of 

 illumination, with the use of a fraction of the gas formerly used. 



