All About Engines

* Fuel and Its Problems 337 supply of blast furnace and coke oven gas avail- able. , Whenever this question of the supply of fuel is raised people ask at once, “ What about oil ? ” The medium oil engine, the petrol engine, and the Diesel engine are so familiar that the mind at once travels to the possibility of securing power without using boilers or gas producers at all, and few people other than engineers, chemists, and geologists have any idea of the magnitude of the oil supply or to what extent it is comparable with that of coal. The broad facts of the case, however, can be put very briefly. The total production of oil in the world, in 1913, was 57 million tons—30 millions in the United States, 10 millions in Russia, and the rest in Rou- mama, Persia, Mexico, and the Far East. On the other hand, the production of coal in Great Britain alone in the same year was 287 million tons. The world’s production of coal is probably about 1,000 million tons, and there seems no reason to believe that oil will ever be able to provide for more than one- twentieth of the world’s power. But when we speak of oil in this way we refer to petroleum, which is obtained by sinking wells into layers of earth far below the surface, which are satu- rated with it. Frequently this is under pressure, so that when the borehole reaches the oil it is forced up in a fountain. Hundreds of thousands of barrels a day are obtained from “gushers” without the trouble of pumping. But oilfields seem to be more quickly worked out than coalfields, so that active w