Mayer, Johann Tobias

Mayer, Johann Tobias (yō`hän tōbē`äs mī`ər), 1723–62, German mathematician and astronomer. In 1751 he became professor of economics and mathematics at the Univ. of Göttingen, and in 1754 director of the observatory there. He is especially noted for his lunar tables (1752), which were important in precisely determining longitude at sea. Mayer is remembered also for his improvements in mapmaking and for the invention of the repeating circle, later used in measuring the arc of the meridian. A collection of his memoirs was published in 1775; a revision of his catalog of 998 zodiacal stars, newly computed, appeared in 1894.