| Description | Letters Patent No. 535,436 dated 30th November 1939, issued to Cannon Iron Foundries Ltd. with Richard Talbot Clayton, Wilfred Eric Benton and Arthur Frederick Oatley, for 'improvements in and relating to heating apparatus burning gas'; report made by Barker, Brettell & Duncan, Chartered Patent Agents, Birmingham for the patent application; provisional specification and complete specification for the same patent; correspondence with Barker, Brettell & Duncan. |