Dictionary of National Biography, 1885-1900/Haselden, Thomas
HASELDEN, THOMAS (d. 1740), mathematician, was for some time schoolmaster at Wapping Old Stairs, and afterwards ‘head-master of the Royal Academy at Portsmouth.’ In 1722 he published ‘Description and Use of … that most excellent Invention commonly call'd Mercator's Chart; to which is added the Description of a new Scale whereby Distances may be measured at one extent of a Pair of Compasses.’ To this was prefixed a letter to Dr. Halley, concerning the Globular Chart, which produced a reply the same year by Henry Wilson in his ‘Description of the Globular Chart,’ with ‘proof that his [i.e. Haselden's] principal argument is false, the rest invalid, and the whole incoherent.’ Haselden soon after printed ‘Reply to Mr. Wilson's Answer to my Letter,’ with a further vindication of the ‘Mercator's Chart,’ and a second letter to Dr. Halley prefixed (1722, 8vo). At that time Haselden designates himself ‘Teacher of Mathematics to his Majesty's Volunteers in the Royal Navy.’ In 1730 he published ‘Mathematic Lessons for Students in the Mathematics and Natural Philosophy, composed by the Abbot de Molières; done into English by T. H.’ In 1788 there was issued a new edition of the ‘Seaman's Daily Assistant,’ said to be by Haselden. Haselden was elected to the Royal Society 17 Jan. 1739–40; but from the tables in Thomson's history of the society it seems doubtful if he was admitted fellow. He died in May 1740. His portrait by T. Faye (1735) was engraved by Faber (1740).
[Evans's Cat. of Engraved Portraits, vol. ii.; Thomson's Hist. Roy. Soc. p. xli.]