its modern development, and the motor car would not have come into general use. The revolution effected by automatic traction alone, with the co-operation of petroleum, would have seemed incredible a generation ago. The pioneer users of motor cars bought their gasoline at drug stores. To-day the “gas” stations in every country village and in connection with every large garage and auto-livery give testimony to the part a single product of petroleum plays in the social and commercial life of the American people. The automobile industry, which could hardly have been born without petroleum as an auxiliary, now represents an enormous investment in this and other countries giving employment to innumerable workmen of all classes. Oil as a source of power is to all intents and purposes an outgrowth of the twentieth century. Its function as a source of light and heat is historical. Lighting by means of oil lamps has in itself undergone great improvements since the early days and the use of oil as a fuel in a manner distinct from its application to automobiles, aeroplanes and other inventions operated by gasoline engines, is steadily increasing. It is taking its place as a substitute for coal, not only in the United States but to a marked extent in other countries. For some of them it may be said to have proved a solution for railroad problems that were at one time almost insuperable. Russia, for instance, for the last thirty years, and up to the time when internal conditions disrupted her industrial organization, utilized her own petroleum for fuel. The railroads of Mexico, Argentina, Brazil and other Latin American countries as well as in Roumania are now served by oil burning locomotives where a decade or so ago coal or wood was employed. In this country the Southern Pacific Railroad and other well known transportation corporations have demonstrated that the locomotive run by liquid fuel is an economic success; in 1919 the amount of fuel oil used for this purpose in the United States was approximately 50,000,000 barrels. Railroad experts have discovered that the steaming capacity of a locomotive running on fuel oil is so materially increased that it is possible to haul with it a greater tonnage at a much increased speed than would be possible with a coal fired engine. [Illustration: “Look boxes” in the “Still House,” where the grades of oil are separated according to gravity, the process being known as the separation of “cuts”] [Illustration: A modern tanker carrying 4,000,000 gallons of oil]