Maskelyne, Nevil, D.D., F.R.S. (1732-1811), was for nearly half a century Astronomer-Royal. He was born in London, and educated at Trinity College, Cambridge, of which he became fellow. In 1761 he was sent by the Royal Society to observe the transit of Venus at St. Helena, and during the voyage he introduced the practice of calculating longitude by lunar distances. In 1763 he went to Barbadoes to test chronometers, and in 1765 became Astronomer-Royal. He induced the Government to print annually his observations, a practice which has been continued with much advantage; and he was founder of the Nautical Almanac, which was first issued in 1766, having had a predecessor in the British Mariner's Guide (1763). Selections from his works were published in 1812. He also took interest in geodesy, and was concerned in the finding of the earth's density by means of experiments made at Schiehallion.