John Barrow

John Barrow (fl. 1735–1774) was an English mathematician, naval historian and lexicographer. His geographical dictionary first appeared in 1756. Life Nothing is known of Barrow's family. He was initially a teacher of mathematics and navigation aboard ships of the Royal Navy. He retired before 1750 and devoted himself to writing and compiling dictionaries and other works related to his knowledge of mathematics and science. Barrow's best-known work was Navigatio Britannica (1750), a practical handbook of navigation and charts still being advertised by its publisher, Mount & Page, in 1787. It included an examination of nautical instruments and explained the recently introduced vernier scale. Barrow seems to have been in close touch with nautical instrument makers while he was a naval instructor. It was not realized until the 20th century that John Barrow the "geographical compiler" mentioned in the British Dictionary of National Biography (1885 onwards) and the teacher of mathematics were the same person. In 1756 he published a geographical dictionary anonymously in London.