Opening of the Cook Gallery at the National Maritime Museum, Greenwich, on 17 July 1968

Abstract

It was with great pleasure that I received the invitation from the Director, Mr Greenhill, to open the Cook Gallery in the National Maritime Museum. For Cook had long been one of my heroes, as one of the greatest navigators and explorers of history. In addition, he was, in Fanny Burney’s words, ‘. . . the most moderate, humane and gentle circumnavigator who ever went upon discoveries’. Cook’s first voyage, which started at Plymouth in August 1768 and which we celebrate today, 200 years later, occurred at a turning point of the technique of navigation. His navigation on his three years’ voyage depended for longitude on the measurement of the angular distance of the moon from the fixed stars. It could take up to four hours of numerical calculation to work out the longitude. Cook had clearly trained himself to be a first-rate observer and an accurate calculator. This method of lunar distance became of practical use at sea only when the essential astronomical data became easily available to seamen. This happened in 1767, the year before his voyage, because of the publication of the Nautical Almanac and Astronomical Ephemeris by the Astronomer Royal. By this method Cook was generally able to determine the longitude to less than 30 miles.