T. Cooke & Sons
In 1924 the company became a wholly owned subsidiary of Vickers. In 1939 another factory was built on a larger site in Haxby Road and during the Second World War, the company employed 3,300 people.
In 1963 the company was renamed Vickers Instruments.
The Haxby Road site was demolished in 2008.
- Taylor, E. Wilfred; Wilson, J. Simms; Maxwell, P. D. Scott. At the Sign of the Orrery: The Origins of the Firm of Cooke, Troughton and Simms, Ltd. (Not dated, no publisher given.)
- Vickers Instruments - Borthwick Institute for Archives, The University of York
- Pritchard, Charles (1868). "Thomas Cooke". Monthly Notices of the Royal Astronomical Society. London: Royal Astronomical Society. 29: 130–135. Retrieved 15 November 2015.
- "Archived copy". Archived from the original on 2011-02-03. Retrieved 2016-02-07.CS1 maint: Archived copy as title (link)
- Focus falls on Vickers Instruments (From York Press)
- "Notes". The Observatory. 45: 403. 1922. Retrieved 15 November 2015. (About the merger with Troughton & Simms.)