ABSTRACT
One of the popular questions about the first transatlantic sailing voyage was how much did the venture owe to innovations in science and technology? In 1492 Christopher Columbus, who captained the first voyage, was a fairly experienced if somewhat eccentric mariner. He was forty-one years old and had probably been at sea since his teens. He was also gradually becoming a man of some scholarship and by the time he died in 1506 he had accumulated an impressive library of scientific books that he had annotated with his own observations. His practical knowledge of navigation was usually sound, though he got his winds and his currents slightly wrong when trying to return quickly from his second New World voyage. His cosmographical the-ory was rather more shaky than his seafaring experience. No serious geographer or astronomer of the late fifteenth century would have denied that the world was round, or that it was therefore theoretically possible to reach China by a western route as well as by the old land route that had taken Venetian traders eastward through the Asian steppes. Any competent mathematician would have known, however, that the circumference of the equator was in the region of 25,000 miles and not the rather smaller figure upon which Columbus optimistically, not to say stubbornly, built his dreams. Columbus thus encountered the Caribbean islands, thirty-three days westward from the Canaries, not so much because he was a better navigator than any rival, but because he was a worse astronomer. When he arrived on the far side of the Atlantic he probably genuinely believed that he had reached islands off the shore of China.
