Steam launch (length 40 ft., beam 6 ft. 9 in.; average speed 9 miles per hour) built for the Viceroy of Egypt by Messrs. Yarrow and Hedley, Engineers, Poplar, and fitted with twin inverted vertical marine engines with 5 in. diameter cylinders (stroke not stated) operating on steam supplied at 80 pounds per square inch by a multitubular locomotive boiler., driving twin propellers two foot in diameter (pitch not stated).