British patent number 24589 of 1912 was granted to James Williamson and Colin Martin Williamson for 'Improvements in the Construction of Cinematograph Cameras'. The patent was applied for on 30 October 1912 and accepted on 10 April 1913. The Williamson company made cinematographic movements for Houghtons and Houghton-Butcher, who sold them under the Ensign trade name. It seems likely that the mahogany camera casing was made by Houghtons themselves.

Although numbers stamped on ciné cameras of this period sometimes relate to the number in a particular batch rather than to sequential production numbers, the numbers blind-stamped onto the base of Williamson cameras seem to indicate the actual serial number. This example is clearly stamped '1', apparently indicating that this was the first example of the Model 4 (1912 patent) to be made.