Testimonials to the performance of Mr. Shorter's propeller as fitted to ship Doncaster. Refers to Edward Shorter's patent no. 2371 of 1800 Feb. 1 for a 'Machine for working and causing the progressive motion of ships and vessels, without sails or oars'. Printed by Wm. Newman, Widegate St, Bishopsgate. Copy, 'photo-lithog. by Maclure & Macdonald'. Certificates from Admiral Sir Richard Bickerton, and the Captains of His Majesty's ships Dragon, Superb etc.