Abstract
THE Royal Observatory was founded in the reign of King Charles II. to assist in the solution of the important and difficult question of determining longitude at sea. The use of the method afterwards known as “lunars” had been suggested. As the moon moves round the sky in a month, its position among the stars changes rapidly: if, then, an almanac can be prepared giving the position of the moon among the stars according to the time of some fixed place, say Greenwich, the navigator can by observation of the moon determine the Greenwich time. It is an easy matter to determine his local or ship time, and the difference gives the longitude. In the seventeenth century the movement of the moon was not known with nearly sufficient accuracy for this method to be available, and even the positions of the fixed stars were very imperfectly charted. The Royal Observatory was founded to remedy these defects, and Flamsteed, the first Astronomer Royal, was charged to make observations for “rectifying the tables of the motions of the heavens and the places of the fixed stars so as to find out the so much desired longitude at sea, for perfecting the art of navigation.”
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D., F. The Royal Observatory, Greenwich. Nature 116, 99–100 (1925). https://doi.org/10.1038/116099a0
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DOI: https://doi.org/10.1038/116099a0