THE FIRST electric toaster appeared in 1909. It toasted one side at a time and required constant vigilance: when the toast was done, you pulled the plug. The first automatic electric toaster was designed in 1919 by Charles Strite, a man sick and tired of burned toast. Americans were skeptical at first about investing in a single-function appliance, but prices dropped and -- such is the allure of toasted bread -- sales mushroomed. From 1922 to 1930 sales tripled, from 400,000 units to 1,200,000, thanks in part to the introduction of sliced bread by Wonder. Toasters now live in 88 percent of American homes; the tiny chrome hearth on the counter may well be the one object that pleases most of the people most of the time.