The Americans, by Alistair Cooke. New York: Berkeley Publishing Company. $ 2.92

British-born Alistair Cooke, the genial host of "Masterpiece Theater" on public, TV, is known outside the United States as the deft and witty author of a weekly "Letter From America," broadcast by BBC Radio on both its home and overseas services.

This anthology contains Cooke's own selection of 50 letters from the past 10 years. He weaves into his narrative sidelights and scraps of information culled from his own vast experience of the US.