The reason why the car buying public gave enthusiastic patronage to gasoline cars and scant encouragement to steam cars was that the use of the steam car requires more mechanical knowledge than does that of the gasoline car, and the work of making repairs is more complicated. The man of today wants to do a thing in the easiest way. His education, through the conveniences supplied in modern life, is all along the line of short cuts to anywhere and anything. “Why work when you don’t have to,” is his motto, and he has never been able to see why he should take the time to become a proficient mechanic to give himself pleasure, when he can buy a gasoline car and escape doing so—and much work in running his car and repairing it, as well. The steam automobile reached the zenith of its vogue prior to 1905. Beginning with that year, its use declined and that of gasoline cars increased. The gasoline type is now almost universal in passenger automobiles, and the fact that the power units in the operation of the gasoline motor are more economical than either electricity or steam, has its bearing on their general popularity. AUTOMOBILE DEMAND MADE ACCESSORIES NECESSARY. A history of the commercializing of the automobile which does not make mention of the manner in which the development of the industry called into being an almost endless list of incidental and accessory products, is not complete. The production of the finished automobile involves a multiplicity of units, and as no automobile manufacturer makes all of these, but depends on independent factories for certain of them, there has been a multiplication of enterprises supplying products entering in the construction of automobiles, whose development and financial success have kept pace with those of the automobile itself. Foremost in the list of accessories for the automobile are tires, and the industry in this product is of vast proportions. The production of automobiles—passenger and freight—having been 1,617,708 in 1916, and the manufacturers having delivered each of these vehicles complete with a set of four tires, the number of tires required for 1916 sales of automobiles alone was 6,470,832. But the tires put out with new automobiles form only a slight proportion of the total tires sold by tire companies. It is stated that each of the over three million cars in use in the United States consumes an average of eight tires a year, so that automobile buyers are purchasers of probably 20,000,000 tires a year. The pneumatic tire was one of the greatest factors in giving the automobile business its impetus. Charles Goodyear, in a broad sense, laid the foundation for popularizing the automobile, when, by accidentally dropping rubber on a stove, he discovered the principle of vulcanization.