Charles Hutton FRS FRSE LLD (14 August 1737 – 27 January 1823) was an English mathematician and surveyor. He was professor of mathematics at the Royal Military Academy, Woolwich from 1773 to 1807. He is remembered for his calculation of the density of the earth from Nevil Maskelyne's measurements collected during the Schiehallion experiment. Life Hutton was born on Percy Street in Newcastle upon Tyne in the north of England, the son of a superintendent of mines, who died when he was still very young. He was educated at a school at Jesmond, kept by Mr Ivison, an Anglican clergyman. There is reason to believe, on the evidence of two pay-bills, that for a short time in 1755 and 1756 Hutton worked in the colliery at Old Long Benton. Following Ivison's promotion to a living, Hutton took over the Jesmond school, which, in consequence of his increasing number of pupils, he relocated to nearby Stotes Hall. While he taught during the day at Stotes Hall, which overlooked Jesmond Dene, he studied mathematics in the evening at a school in Newcastle. In 1760 he married, and began teaching on a larger scale in Newcastle, where his pupils included John Scott, later Lord Eldon, who became Lord High Chancellor of Great Britain. In 1764 Hutton published his first work, The Schoolmasters Guide, or a Complete System of Practical Arithmetic, which was followed by his Treatise on Mensuration both in Theory and Practice in 1770. At around this time he was employed by the mayor and corporation of Newcastle to make a survey of the town and its environs. He drew up a map for the corporation; a smaller one, of the town only, was engraved and published. In 1772 he brought out a tract on The Principles of Bridges, a subject suggested by the destruction of Newcastle bridge by a high flood on 17 November 1771. Hutton left Newcastle in 1773, following his appointment as professor of mathematics at the Royal Military Academy, Woolwich. He was elected a Fellow of the Royal Society in July, 1774 He was asked by the society to perform the calculations necessary to work out the mass and density of the earth from the results of the Schiehallion experiment – a set of observations of the gravitational pull of a mountain in Perthshire made by the Astronomer Royal, Nevil Maskelyne, in 1774–76. Hutton's results appeared in the