ROY, a surname, from a Gaelic word signifying red, and like More, great, Begg, little, Bane, fir, and similar names, originally assumed from some personal quality, such as the colour of the hair or complexion, in the first bearer.

ROY, ROB, that is, RED ROB, see MACGREGOR.

ROY, WILLIAM, Major-General, an eminent antiquarian, was born in the parish of Carluke, upper ward of Lanarkshire, about the year 1720. In the winter of 1746, while colonel of artillery, he and his engineers, under colonel Watson, made an actual survey of Scotland on a very large scale, and the result of their labours is now known as the “Duke of Cumberland’s Map,” the original of which is in the Ordnance Office. This map, on which the sites of all the Roman camps and other remarkable objects are accurately pointed out, he afterwards reduced to a smaller size, and had a few engraved as presents to his friends. He contributed many important papers to the Transactions of the Royal Society; and for one of these, being a curious account of the measurement of a base on Hounslow-Heath, he obtained the Copley medal. A short time before his death, he had completed, by command of the king, a most elaborate set of trigonometrical experiments and observations, to determine the exact latitude and longitude of the royal observatories of Greenwich and Paris, according to a mode proposed by himself in some of his papers in the Philosophical Transactions. They were illustrated by tables computed by actual measurements, to enable him to take which his majesty had furnished him with some very expensive trigonometrical instruments. He had drawn up and presented to the Royal Society an account of these experiments, the printing of which he was engaged superintending for their Transactions, when he was seized with an illness of which he died in two hours, July 1, 1790. At the time of his death, besides being a major-general in the army, he was deputy quarter-master-general, colonel of the 30th foot, surveyor-general of the coasts, and a fellow of the Royal Society, as well as of the Society of Antiquaries. His valuable work, entitled ‘Military Antiquities of the Romans in Britain,’ was published at the expense of the Antiquarian Society of London, in 1793. His works are:

Experiments and Observations made in Britain, in order to attain a Rule for Measuring Heights with the Barometer. Lond. 1778, 4to.
An Account of the Mode proposed to be followed in the Trigonometrical Operation for determining the relative situation of the Royal Observatories of Greenwich and Paris. Lond. 1787, 4to.
An Account of the Trigonimetrical Operations whereby the distance between the Meridians of the Observatories of Greenwich and Paris has been determined. Lond. 1790, 4to.
The Military Antiquities of the Romans in Britain, and particularly their ancient system of Castramentation, illustrated from vestiges of the Camps of Agricola existing there; published by the order and at the expense of the Society of Antiquaries of London. Lond. 1793, fol. (Posth.)
Experiments and Observations made in Britain, in order to obtain a Rule for measuring Heights with the Barometer. Phil. Trans. 1777, Abr. xiv. 226.
Account of a Measurement of a Base on Hounslow-Heath. Ib. 1785, xvi. 22. Reprinted separately same year.
An Account of the Mode proposed to be followed in Determining the relative Situation of the Royal Observatories of Greenwich and Paris. Ib. 1787, 240.