Dictionary of National Biography, 1885-1900/Purdy, John

by Albert Frederick Pollard

PURDY, JOHN (1773–1843), 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. This work went through many editions, the fifteenth appearing in 1894, edited by Mr. W. R. Kettle, F.R.G.S. 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’ [see Rennell, James]. He died on 29 Jan. 1843.

Alexander George Findlay [q. v.], who succeeded to his position as a leading hydrographer, edited and improved a large number of Purdy's works. The more important of Purdy's writings are:

1. ‘Tables of Positions, or of the Latitudes and Longitudes of Places,’ &c., 1816, 4to.
2. ‘The Columbian Navigator,’ 1817, 8vo; other editions 1823–4, 2 vols., 1839, and 1847–8.
3. ‘Memoir to accompany the General Chart of the Northern Ocean,’ 1820, 8vo.
4. ‘The New Sailing Directory for the Ethiopic or Southern Atlantic Ocean,’ 1837, 8vo; 3rd edit. Findlay, 1844. Similar ‘Sailing Directories,’ dealing with many other regions, were also published by Purdy.
5. ‘The British American Navigator,’ 2nd edit. 1843, 8vo.

A fairly complete list of Purdy's maps and charts is given in the ‘Catalogue of the Map Room of the Royal Geographical Society.’ The chief are: a chart of the Atlantic Ocean (1812); a ‘map of Cabotia, comprehending the Provinces of Upper and Lower Canada,’ &c. (1814); a map of the world on Mercator's Projection (1825); The Azores (1831); Jamaica (1834); the Viceroyalty of Canada (1838); Newfoundland (1844). Others published by Findlay, after Purdy's death, include the Indian and Pacific Oceans (1847); St. George's Channel (1850); the coasts of Spain and Portugal (1856). His nephew Isaac published a chart of the coasts of China in 1865.

[Works in Brit. Mus. Libr.; Cat. of Library and Map Room of Royal Geogr. Soc.; Review of British Geogr. Work, 1789–1889, p. 190; Proc. Royal Geogr. Soc. xix. 381; Athenæum, 1875, i. 657; Lowndes's Bibl. Man.; Allibone's Dict. of English Lit.; information supplied by Messrs. R. H. Laurie, Minories.]

A. F. P.