Illustrations of a steam launch (length, 33 ft.; beam, 8 ft.; speed, 8.5 miles per hour.) fitted with a twin cylinder (diagonal) 5.25 in. by 6.5 in. stroke, engine operating at 250 revolutions per minute on steam supplied at 75 pounds per square inch by a return tubular boiler. Built by Messrs. Yarrow and Co. for Messrs. Siemens Brothers, to accompany telegraph expeditions and assist in the laying of the shore ends of cables.