A History of the Growth of the Steam-Engine

by Robert Henry Thurston

In the year 1736, Jonathan Hulls took out an English patent for the use of a steam-engine for ship-propulsion, proposing to employ his steamboat in towing. In 1737 he published a well-written pamphlet, describing this apparatus, which is shown in [Fig. 66], a reduced fac-simile of the plate accompanying his paper.

He proposed using the Newcomen engine, fitted with a counterpoise-weight and a system of ropes and grooved wheels, which, by a peculiar ratchet-like action, gave a continuous rotary motion. His vessel was to have been used as a tow-boat. He says, in his description: “In some convenient part of the Tow-boat there is placed a Vessel about two-3rds full of water, with the Top closed; and this Vessel being kept Boiling, rarifies the Water into a Steam, this Steam being convey’d thro’ a large pipe into a cylindrical Vessel, and there condensed, makes a Vacuum, which causes the weight of the atmosphere to press down on this Vessel, and so presses down a Piston that is fitted into this Cylindrical Vessel, in the same manner as in Mr. Newcomen’s Engine, with which he raises Water by Fire.

Fig. 66.—Hulls’s Steamboat, 1736.

“P, the Pipe coming from the Furnace to the Cylinder. Q, the Cylinder wherein the steam is condensed. R, the Valve that stops the Steam from coming into the Cylinder, whilst the Steam within the same is condensed. S, the Pipe to convey the condensing Water into the Cylinder. T, a cock to let in the condensing Water when the Cylinder is full of Steam and the Valve, P, is shut. U, a Rope fixed to the Piston that slides up and down in the Cylinder.

“Note. This Rope, U, is the same Rope that goes round the wheel, D, in the machine.”

In the large division of his plate, A is the chimney; B is the tow-boat; CC is the frame carrying the engine; Da, D, and Db are three wheels carrying the ropes M, Fb, and Fa, M being the rope U of his smaller figure, 30. Ha and Hb are two wheels on the paddle-shafts, II, arranged with pawls so that the paddle-wheel, II, always turns the same way, though the wheels Ha and Hb are given a reciprocating motion; Fb is a rope connecting the wheels in the vessel, Db, with the wheels at the stern. Hulls says:

“When the Weight, G, is so raised, while the wheels Da, D, and Db are moving backward, the Rope Fa gives way, and the Power of the Weight, G, brings the Wheel Ha forward, and the Fans with it, so that the Fans always keep going forward, notwithstanding the Wheels Da, D, and Db move backward and forward as the Piston moves up and down in the Cylinder. LL are Teeth for a Catch to drop in from the Axis, and are so contrived that they catch in an alternate manner, to cause the Fan to move always forward, for the Wheel Ha, by the power of the weight, G, is performing his Office while the other wheel, Hb, goes back in order to fetch another stroke.

“Note. The weight, G, must contain but half the weight of the Pillar of Air pressing on the Piston, because the weight, G, is raised at the same time as the Wheel Hb performs its Office, so that it is in effect two Machines acting alternately, by the weight of one Pillar of Air, of such a Diameter as the Diameter of the Cylinder is.”