Roy, William

Name: William Roy

Achievements: Paris-Greenwich meridional project.

Born: May 4, 1726; Milton Head, Lanarkshire, Scotland

Died: July 1, 1790; London, England (Aged 64)

Field & Discipline: Military; Soldier

Language: English

Father: John Roy

Mother: Unknown

Siblings: James

Spouse: Unknown

Children: Unknown

Education: Carluke parish school; Lanark grammar school

Major Work:

“An Account of the Trigonometrical Operations by which the Distance between the Meridians of the Royal Observatories of Greenwich and Paris has been determined” (1790)

Life & Times:

In 1747, as part of theEnglish plan to provide easier access to the Scottish Highlands so as to subdue rebellious locals, Roy was involved in the construction of a British army camp at Fort Augustus and in overseeing road-making by the troops.

He also helped in the preparation of a map of Scotland on which his lifelong interest in antiquities is demonstrated by the inclusion of the sites of all known Roman camps and headquarters.

Roy was commissioned in the regiment of the 4^th King’s Own Foot and in 1755 he was appointed practitioner-engineer.  In 1759,  after active service in France, and by now promoted to engineer and captain in the corps of engineers, Roy took part in the battle of Minden in Germany under the command Lord George Sackville. In the same year he was became captain of a company in the corps of Highlanders.

He remained in Germany until November 1761 when he was appointed quartermaster-general of forces in south Britain and promoted to the rank of major. As lieutenant-colonel, he served as deputy quartermaster-general in Germany from 1762 until peace was declared in 1763.

After a scheme to survey the whole of Great Britain fell through, he went to Scotland in 1764 to conduct his own research on military antiquities. After being appointed surveyor-general of the coasts and engineer for military surveys in Great Britain, Roy worked in France, Ireland, the Channel Islands and Gibraltar.

In 1783, as major-general in the Royal Engineers, he was seconded to the British government to work on a project was initiated by the French and based on the surveying work of the [work related to] Cassini* family.

The aim of the project was to establish a trigonometrical connection between the observatories of Paris and Greenwich in order to determine the difference of longitude. Roy chose Hounslow Heath in England as a base line and in the summer of 1794 measured a base of 27,404 feet. The operation was accomplished by using cased glass tubing, seasoned wood rods, and a coffered steel chain made by [used materials by] Ramsden*.

The project stimulated great interest and Hounslow Heath, until then famous only as a notorious haunt of highwaymen, became a fashionable place to visit. Roy presented a paper on the project in the “Transactions” of the Royal Society in 1785 and received the Copley medal of the Royal Society for his work. He added to his paper an account of the method he proposed be followed to determine the relative situations of the Greenwich and Paris observatories.

This led to the king ordering him to carry out the work and in 1787 Roy carried out a complicated set of trigonometrical experiments and observations to determine the latitude and longitude of the two observatories. The king supplied him with several costly trigonometrical instruments and Roy produced tables computed from actual measurement.

He continued his work of triangulation from the Hounslow base to the Kentish coast. In September 1787 he met the French commissioners at Dover and they co-ooperated on observations connecting the two sides of the channel.

His work in 1788, completing a series of secondary triangles in southern England, formed the basis for a topographical survey of Middlesex, Surrey, Sussex and Kent.  Roy was correcting the proofs of a paper entitled “An Account of the Trigonometrical Operations by which the Distance between the Meridians of the Royal Observatories of Greenwich and Paris has been determined” when he died.

Extra Connections: His work was developed by [work continued by] Thomas Drummond*

He worked with [a colleague was]Colby*

Assessment: Roy was the leading British surveyor in the Paris-Greenwich meridional project.

Oneliner: William Roy, Paris-Greenwich surveyor

Bibliography:

• Chambers Encyclopedia of Eminent Scotsmen.
• Dictionary of National Biography.