The first detailed scheme for applying steam-power to ship propulsion was contained in the patent of Jonathan Hulls, in 1736. Though great credit is generally given to this inventor (who has even been dubbed the father of steam navigation), it does not appear that in reality he contributed much to the advancement of the problem; which was, indeed, still waiting on the development of the steam engine. Hulls’ notion, explained in a pamphlet which he published in 1737, was to connect the piston of a Newcomen engine by a rope gearing with some wheels mounted in the waist of the vessel, which wheels oscillated as the piston moved up and down. These wheels were in turn connected by rope gearing with a large fan-wheel mounted in a frame rigged out over the vessel’s stern, the fans in their lowest position dipping into the water. The oscillating motion of the inboard wheels was converted into a continuous ahead motion of the fan-wheel by means of a ratchet. With this machinery he designed to tow ships in harbours and rivers. It must, however, be remarked that the invention was never more than a paper project; and that if Hulls had tried to translate his ideas into three dimensions he would have encountered, in all probability, insuperable practical difficulties. One very original suggestion of his certainly deserves notice; as a special case he proposed that when the tow-boat was used in shallow rivers two cranks, fitted to the axis of his driving wheels, should operate two long poles of sufficient length to reach the bottom of the river; these trailing poles, moving alternately forward, would propel the vessel. Here is an early application of the crank. But in this case it will be noted that the crank is driven, and that it converts a rotary into a reciprocating motion; in short, it is an inversion of the driving crank which, as applied to the steam engine, was not invented till some years later.