Thomas Frederick Colby

Thomas Frederick Colby FRS FRSE FGS FRGS (1 September 1784 – 9 October 1852), was a British major-general and director of the Ordnance Survey (OS). A Fellow of the Royal Astronomical Society and Royal Society, Colby was one of the leading geographers of his time.

An officer in the Royal Engineers, Colby overcame the loss of one hand in a shooting accident to begin in 1802 a lifelong connection with the Ordnance Survey. His most important work was the Survey of Ireland. He began planning this enormous enterprise in 1824 and directed it until 1846, in which year the final maps made by the survey were almost ready for issue. He was the inventor of the "Colby Bar" (a compensation bar), an apparatus used in base-measurements.

He was the eldest child of Major Thomas Colby, Royal Marines (d. 1813), and his wife, Cornelia Hadden, sister of James Murray Hadden. He was born at St. Margaret's-next-Rochester on 1 September 1784. He was brought up by his father's sisters at Rhosygilwen, near Cilgerran, Pembrokeshire, West Wales, and at school at Northfleet, Kent, under William Crakelt. He went on to the Royal Military Academy, Woolwich, and passed out for the Royal Engineers while still 16.

Colby attracted the notice of Major William Mudge, director of the Ordnance Survey, who arranged in 1802 to have him attached to the Survey. His first task was sector observations made at Dunnose, Isle of Wight in the summer of 1802. In December 1803, when on duty at Liskeard, Colby met with an accident through the bursting of a pistol loaded with small shot with which he was practising, his left hand having to be amputated at the wrist, and part of the gun being permanently lodged in the skull. In 1804 he was observing the pole star for azimuths at Beaumaris; in 1806 he was assisting Mudge in the measurement of a base-line on Rhuddlan Marsh, near St. Asaph, and in astronomical observations in Delamere Forest, Cheshire, and on the Yorkshire moors. Later he was selecting trigonometrical stations on the mountains in South Wales.

...
Wikipedia