Captain Thomas Drummond (10 October 1797 – 15 April 1840), from Edinburgh, Scotland, was an army officer, civil engineer and senior public official. Drummond used the Drummond light which was employed in the trigonometrical survey of Great Britain and Ireland. He is sometimes mistakenly given credit for the invention of limelight, at the expense of Sir Goldsworthy Gurney. However, it was Drummond who realised their value in surveying.
Drummond was the second of three sons. Despite his father dying when he was young, he credited his mother with getting him through his education at Edinburgh High School and then on to be a Royal Engineer cadet at Woolwich Academy in 1813. He showed an early gift for mathematics. After Woolwich he was stationed in Edinburgh and was involved with public works. He was bored with this and had enrolled at Lincolns Inn when he was recruited to use his trigonometry to help conduct a survey in the Highlands.
This new work was done in the summer with the more difficult months being passed in London. Drummond took this opportunity to improve his knowledge of mathematics and science. He attended lectures by Sir Michael Faraday. At these he learned of the discovery of limelight.