1, 2, 3, 4, 5, are cylinders 18 feet long or high and 3 feet diameter, so that the surface of each piston has 1,296 square inches acting with an atmospheric pressure of 15 lbs. to the square inch, causes a pressure of 19,440 lbs. to each cylinder (saying nothing of friction, which will be accounted for later); 6, 7, 8, 9, 10, pistons of each cylinder, as they must be placed when the engine begins to work; 6, 7, 8, 9, causing a vacuum under each piston (as they have for the first time been brought into their present situation by main force), afterwards, when the engine is permitted to start, they will regulate themselves; No. 10 lies flat on the bottom of the cylinder; 11, 12, 13, 14, 15, piston rods acting on shaft No. 16; 17, wheel to communicate the engine's power to the machinery of the engine itself; 18, wheel to communicate the engine's power to the wheel or propelling screw of a ship, manufactory, locomotive, etc. Stuckey's Device In 1842, William Henry Stuckey, Esquire, of St. Petersburgh, applied for a British patent on "A Pneumatic Engine for Producing Motive Power." His specifications describe his alleged invention as follows: [Illustration] Fig. 1 is a front view of my said pneumatic engine, partly in section. A¹ and B¹ two horizontal cylinders, united at their inner extremities a, a, which rotate on gudgeons that have their bearings C, C, in the upright standards D, D; A² and B² two pistons which work to and fro in these cylinders; E¹ and E³ two hollow arms or tubes which radiate from the cylinder A¹, and E², E⁴, two similar arms or tubes which radiate in opposite directions from the cylinder B¹, each cylinder having an open communication with the arms or tubes attached to it. F¹, F², F³, and F⁴, four other cylinders, affixed to a circular ring R, R, open at top to the atmosphere, and open at bottom to the radial tubes E¹, E², E³, E⁴, connected with them at their outer extremities. G¹, G², G³, G⁴, pistons working in the cylinders F¹, F², F³, and F⁴, and H¹, H², H³, and H⁴, caps screwed on to the flanges of the cylinders. The different parts described form a wheel, which, on being set in motion, rotates on the gudgeons in the bearing C, C. The motion is produced as follows:--I adjust the wheel so that the tubes E¹ and E³ shall be in a vertical position; and pour into the tube E¹, through the cylinder F¹, withdrawing the piston G¹, as much mercury or other suitable fluid body (previously determined by calculation) as will fill the tube from the point of its connection with the inner cylinder A¹ up to the bottom (_a_, _a_,) of the outer cylinder F¹. The mercury thus introduced flows into the cylinder A¹ at the back of the piston A², and presses that piston forward to the extremity of its range, the piston G¹ being then restored to its place in the cylinder F¹, and pressed close down on the mercury in the tube E¹.