Invention: The Master-key to Progress

by Bradley A. Fiske

One of the early influences of the art of printing was to bring to the notice of some restless minds the writings of Hero and Archimedes. In Hero's Pneumatics, published more than 120 years before Christ, he gives such a clear account of an invention of his own, in which the expansive force of steam was used to give and maintain motion, as to establish thoroughly his right to the basic invention of the steam engine. He described three apparatus that he devised. In one, the currents of air and aqueous vapor rising through a tube from a hollow sphere, containing water, under which a fire is burning, support a ball placed immediately above the tube, and make it seem to dance. In another apparatus, a hollow sphere into which steam has arisen from what we now call a boiler, is supported on a horizontal or vertical axis, and provided with tubes that protrude from the sphere, and are bent at right angles to the radius and also to the pivot. The inner ends of these tubes lie within the sphere, so that the steam passes from the sphere through the tubes. As soon as this happens, the sphere takes up a rapid rotation, that continue so long as the steam continues to escape from the nozzles of the tubes, which point rearwardly. A third apparatus was merely an elaboration of the second, in that the sphere was connected with an altar which supported a large drum on which were figures representing human beings. The fire being lighted, the sphere would soon begin to revolve, and with it the drum; and the figures on it would seem to dance around, above the altar. The invention was probably to impress the people with the idea that the priests were exerting supernatural power.

Hero's Altar Engine

Hero's wonderful invention remained unused and unappreciated for nearly 2,000 years. About 1601, an Italian named Della Porta, published a book that seems to show acquaintance with it, also with the fact that if water be heated it is converted into a gas that can raise water to a height. In 1615, a Frenchman named de Caus published a book in which he showed a hollow sphere into which water could be introduced through an orifice that could then be closed; the sphere carrying a vertical tube that dipped into the water at its lower end, and ending in a small nozzle at its upper end. When a fire was started under the sphere, the air in the upper part expanded, and forced down the water that occupied the lower part, so that a jet of water would soon issue from the upper end of the tube. Of course, this was really less than Hero had done, because the appliance described did not constitute a machine, in any real sense of the word.

In 1629, an Italian named Branca carried Hero's invention a step further, by inventing a simple apparatus whereby the revolution of Hero's hollow sphere was communicated to a series of pestles in mortars, and put to the useful work of compounding drugs. Branca seems entitled to the basic invention of the steam engine as an industrial machine.

About 1663, the Marquis of Worcester invented a steam engine that exerted about two horse-power, and was employed to raise water from the Thames River, and supply it to the town of Vauxhall. Six years later (1669) Captain Thomas Savery erected a steam engine about twenty-five feet above the water in a mine, and successfully drew water out. This was a very important feat, because the difficulties surrounding the problem of freeing the mines from water were extremely great, and the desirability of overcoming them was equally so. In Savery's engine, there were two boilers in which steam was raised, and two receivers communicating with them. Steam being admitted to one receiver, the connection with the boiler was shut off by a valve, and a cold jet was then suddenly thrown on the receiver, condensing the steam and forming a partial vacuum. This vacuum the water below immediately rushed up to overcome. Connection with the pipe leading down was then shut off, and steam introduced to the receiver. This steam forced out the water from the receiver into a pipe, which discharged it above. This operation was then performed by the other boiler and receiver; so that, by their continued and alternate action, a fairly continuous stream of discharged water was maintained.

This invention was quickly followed by Captain Savery with another, by means of which the discharge stream was made to fall on a mill-wheel, as though from a natural waterfall. Several of these machines were erected for actuating the machinery of mills and factories in the district.

In 1690, Dr. Papin invented a steam engine, in which he used a cylinder containing water, with a piston so arranged that, when the water was heated, the steam would raise the piston. The fire being then removed the pressure of the atmosphere would force down the piston. This was followed shortly by an invention of Newcomer and Cawley, which was a very considerable advance on previous engines. It comprised a separate boiler and furnace, a separate cylinder and piston, means for condensing the steam in the cylinder by injecting water into it, and a system of self-acting valves that were opened and closed by a long beam that was moved by the piston. Furthermore, this beam communicated motion to a pump that pumped the water up directly. This engine was so efficient and so practically useful, that it was very generally introduced into service for draining mines throughout England. About 1775, Smeaton built an engine carefully designed on these lines, of which the cylinder was 72 inches in diameter, and the length of stroke was 10 feet and 6 inches.

In 1725, Jacob Leupold invented an engine, in which the work was done by steam alone, instead of by the atmosphere, as in the engines that immediately preceded it. Leupold used two cylinders. They were open at the top to the atmosphere as in the others, but he used higher pressures of steam, and arranged a four-way cock between the bottoms of the two cylinders in such a way that the bottom of each cylinder, in its turn, was connected to the boiler or to the open air. Each cylinder actuated directly a separate vibrating beam, which in turn actuated the piston of a pump; the two pistons acting reciprocally, each drawing up water in its turn.