William Roy was a Scottish engineer and surveyor whose innovative geodetic mapping techniques played an important role in the development of surveying. He mapped the inhospitable Scottish mainland, created ground-breaking battle plans for the military and developed on-ground triangulation in surveying. But perhaps his most important legacy is the Ordnance Survey of Great Britain, which was a continuation of his Anglo-French survey and began shortly after his death.
Early Life & Surveying the Scottish Highlands
Roy was born in South Lanarkshire, in 1726. One of the few things known about his early life is that a number of his family members worked as factors, supervising the estate of wealthy Lairds, and he grew up in an environment in which land surveys and mapping were common. After he attended Lanark Grammar School, he is believed to have moved to Edinburgh, where he developed his surveying skills, probably as a civilian draughtsman at Edinburgh Castle’s Board of Ordnance. He became a respected land surveyor and was soon carrying out private surveys at the Callander family’s Craigforth estate. In 1747, Roy was employed to assist with a military survey of the Scottish Highlands under the command of the Duke of Cumberland. Roy had no military rank but Lieutenant-Colonel David Watson appointed him as an assistant to the quartermaster, who led a team of six soldiers. By 1752, the Highlands had been surveyed and the project was extended to cover the Lowlands. But it was cut short when the Seven Years War began. Reporting on the measurement of the Hounslow Baseline, Roy wrote that the map was “in an unfinished state and is to be considered as a magnificent military sketch rather than a very accurate map of the country, and it would have been completed, and many of its imperfections no doubt remedied, but for the breaking out of war in 1755”.
Campaigning for a National Land Survey
In 1756, Roy was posted to South England, where he assessed the coasts’ readiness for a French invasion, which was expected. He then went to France, where he developed a new technique for creating battle plans, which was praised as clear and user-friendly, and adopted by the military. By the end of the war, in 1763, Roy was a lieutenant colonel in the regiment and director of the engineers of the Board of Ordnance. He returned to London, where he proposed a comprehensive national survey or, as he put it, “a good military plan or map of the whole country”. He felt strongly that the survey should cover not only the vulnerable southern coasts, but the whole of the UK. Due to the expense of the Seven Years War, and later, the American War of Independence, the survey was considered too expensive.
Laying the Foundations for the Ordnance Survey of Great Britain
In 1765, Roy became surveyor-general with a direction to "inspect, survey and make reports from time to time of the state of the coasts of this Kingdom and the islands". He travelled extensively and his sketches and plans are now kept at the British Library. He completed topographical surveys of Middlesex, Surrey, Kent and Sussex using his new Ramsden Theodolite, and established the principal of on-ground triangulation in surveying. Aged 57, Roy started his Anglo-French Survey, mapping the relative positions of Greenwich Observatory and the Paris Observatory. First, he measured bases at Hounslow Heath and Romney Marsh, next, he measured the angles of the triangles and finally, he made a calculation of all the triangles. Roy died in London, in 1790, and a year later, the Ordnance Survey of Great Britain began, as an extension of his Anglo-French Survey. His use of scientific advancements and mathematical formulas paved the way for geodetic surveying and he is considered one of the fathers of modern surveying.