Section 2 Until within a recent period the trade of shoemaker was an active one, all boots and shoes being made by hand. At the present time, however, the old-time shoemaker, with his bench, lapstone, last and awls has almost gone out of business, except as a cobbler, mending instead of making having become his usual occupation. In his place has come the factory hand, nearly all footwear being now a product of machinery, and this of greatly varied and effective character. In this form shoemaking has become a thriving industry in New England and in some other parts of the United States. This method has greatly decreased the cost of shoes, invention having so hastened and cheapened all its processes that the number of shoes that it would take an old-time shoemaker a year to make can be turned out in a few hours by modern machinery. what is the central idea of section 2?