Barr and Stroud Rangefinder
The Barr & Stroud Rangefinder, a device used to accurately determine distances for military purposes, was widely used by armies across Europe before the First World War, and remained in use by the Royal Navy until it was rendered obsolete by the development of radar in World War Two.
It was developed by two teachers who met at the Yorkshire College of Science: Archibald Barr, Professor of Civil and Mechanical Engineering, and William Stroud, Cavendish Professor of Physics. On seeing a War Office advertisement in the Engineeringmagazine, May 25th 1888, to design a precision rangefinder, the two set about developing one. With little knowledge of such instruments, their initial designs were unsuccessful; but in 1891 the Admiralty returned to them to submit further designs, and a year later a contract was agreed to construct six for the British Army.
The ultimate success of their instrument belies the struggles they encountered in the venture. While Barr moved to Glasgow in 1889 to become Regius Professor of Civil Engineering and Mechanics, Stroud stayed in Leeds, earning extra money to fund their work by giving popular evening lectures in the towns and villages around the city, whilst by day remaining Professor at the Yorkshire College until 1909. The magic lantern which Stroud used in his lectures is also a part of our collections.