H. L. Barber, Story of the automobile: Its history and development from 1760 to 1917
“ 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. ”
