New Heroes vs. Old - Thomas Sowell - Townhall Conservative

New Heroes vs. Old - Thomas Sowell - Townhall Conservative: "People today who complain about the automobile's pollution have no idea how much more pollution there was before the automobile came along. In New York City, for example, the 40,000 horses that were the backbone of the city's transportation, before the automobile, produced 400 tons of manure per working day, along with 20,000 gallons of urine."