Science by Litigation: A Cosmographic Feud

The Empirical Reconstruction of Columbus' Navigational Log and Track of his 1492–1493 Discovery Voyage

“…The quadrant (see Figure 6) and astrolabe put aboard Columbus' vessels were furnished by one such contractor and were placed aboard every vessel regardless of whether the incumbent pilot or master was capable of using the instruments. When Sebastian Cabot became Spain's Piloto Major he attempted to obtain a monopoly on this lucrative trade of furnishing these instruments to the Crown which was challenged in court (Lamb 1969). 18 The first report in the log of Columbus using a quadrant to take a latitude sight on Polaris was on 2 November, 1492 while on the northeastern shore of Cuba.…”

“…When Sebastian Cabot became Spain's Piloto Major he attempted to obtain a monopoly on this lucrative trade of furnishing these instruments to the Crown which was challenged in court (Lamb 1969). 18 The first report in the log of Columbus using a quadrant to take a latitude sight on Polaris was on 2 November, 1492 while on the northeastern shore of Cuba. He obtained a reading of 42 degrees from the equinoctial, which is about 1,142 nautical miles too far north, but he dutifully entered it in the log.…”