Serious work on medieval technology began <i>c 1931 with a further impetus in mid-1950s, and modern editions of pre-1500 texts began to appear at the same time. By now it is clear that the late 15th-century European explorers were soundly backed by the technology of ships, navigation, armament, agriculture and manufactured goods. (See also author's Medieval engineering and the sociology of knowledge, <i>Pacific Hist. Rev., 44, 1975, 1-21.) -- AATA