John Purdy

The Dictionary of National Biography has this to say about Purdy: “…hydrographer, the son of a bookseller at Norwich, was born in 1773. He early turned his attention to the study of naval charts and similar subjects. Before 1812 he succeeded De la Rochette as hydrographer to Messrs. Laurie & Whittle, of 53 Fleet Street, London, and in that year published a ‘Memoir, descriptive and explanatory, to accompany the New Chart of the Atlantic Ocean,’ 4to…. Purdy does not seem to have taken part in hydrographic expeditions himself, and his work consisted in writing works and constructing charts based upon the reports of others; but eventually he became the foremost authority of his time on hydrography. He was mainly instrumental in bringing ‘Rennell's Current’ before the notice of navigators, and in 1832 Rennell's daughter, Lady Rodd, entrusted to Purdy the editing of his ‘Wind and Current Charts’…. He died on 29 Jan. 1843.”