of "Camera House", Farringdon Avenue, London, EC4
1866 The English supplier of magic lanterns and slides W. Butcher and Son was established at Blackheath, London.
1895 The firm was advertising using the Primus trademark. Much of their extensive range was probably bought in from Germany and sold under their own name.
1902 W. Butcher and Son became W. Butcher and Sons.
1913 Changed to W. Butcher and Sons Ltd. Butcher also produced the well known Junior Lecturers Series using the Primus trademark.
1914 Manufacturers of cameras, photographic apparatus, cinematographs etc. Specialities: cameras and photographic apparatus of all kinds, cinematograph cameras and projectors, films and everything connected with the animated picture trade. Employees 650. 
1915 Houghtons Ltd and W. Butcher and Sons Ltd formed a joint venture Houghton-Butcher Manufacturing Co Ltd to share manufacturing facilities. This agreement was essential for Butcher, which had no manufacturing plant and was mainly trading imported German cameras before the outbreak of World War 1. The two companies continued to trade separately, and the camera designs remained distinct.
1922 Listed Exhibitor - British Industries Fair. Manufacturers of Primus Engineering - the Wood and Metal Constructional Toy; Electric and Clockwork Motors, Motor Chassis Sets, Experimental Chemistry Outfits, etc. (Stand No. F.31)
Also: Sole Selling Agents for the Williamson Kinematograph Co. Cinematograph Cameras, Printers, Perforators, and Dark Room Equipment; Projectors for the Theatre, Home and Educational. Catalogues free on application. (Stand No. G.61.O)