Through these machines run rivers of oil. From them streams a steady line of parts. The whole scope of the tool business is broadened. In the old days--which means, in the automobile business, about ten years ago--an order for ten turret-lathes was considered large; now the motor-makers order seventy-five at a time by telegraph, and do not regard it as more than part of the day's work. The whole effect of this revolution in machinery is that time is saved, labor is economized, and it is possible to achieve quantity production. This, in turn, enables the large manufacturer to turn out a good car at a moderate price. So with steel, where likewise wonders have been wrought. Ten years ago the great mass of the steel output in this country was in structural metal and rails. We had to import our fine alloy and carbon steels from Germany and France. But the automobile-makers had to have the lightest and toughest metal, and they did not want to import it. The result was that our mills began to produce the finer quality to meet all motor needs, and it is now one of the biggest items in the business. In half a dozen other allied industries you find the same expansion as you saw in rubber, steel, and machinery. For instance, the automobile-makers buy twenty million dollars' worth of leather a year. So great is the demand that a composition substitute was created, which is used on sixty per cent. of the tops. A new industry in colored leather for upholstery has been evolved. Wood, too, has had the same kind of experience. Whole forest areas in the South have been denuded for hickory for spokes. A few years ago, aluminum was used on ash-trays and exposition souvenirs. Now hundreds of thousands of pounds are employed each year for sheathing and casings on motor-cars. No essential of the automobile, however, is of more importance than gasoline. Here is the life-blood of the car. It is estimated that there are to-day three hundred thousand cars in the United States that travel fifteen miles a day. There are fifteen miles of travel in each gallon of gasoline. This makes the daily consumption three hundred thousand gallons. At an average price of fourteen cents a gallon, here is an expenditure of forty-two thousand dollars for gasoline each day, or more than fifteen million dollars a year. To this must be added the excess used in cars that work longer and harder, and in the host of taxicabs that are in business almost all the time, which will probably swell the annual expenditure for gasoline well beyond twenty millions.