1723-1762

German cartographer and astronomer remembered for his lunar tables, which allowed accurate determination of longitude at sea. Mayer claimed the British government's prize for best such method, and three years after his death the British Board of Longitude awarded his widow 3,000 pounds. Mayer also devised a method for fixing geographical coordinates independent of astronomical observations, invented a method for determining eclipses, investigated stellar proper motions, and produced an accurate map of the Moon's surface.