Talk:Thomas Newcomen/Material from Wikipedia user Dr. Gabriel Gojon/Papin's Early Inventions

Papin's Early Inventions By 1680, Papin had made a major breakthrough toward controlling highly compressed steam, in the form of his "New Digester for softening Bones, etc." a steam pressure cooker. This device consisted of a cylinder with thick walls (as prescribed by Huygens in his 1666 program), in which was enclosed water along with bones, tough meat, and so forth. The whole device was then placed on a fire to cook (see Figure 2). Although Papin's immediate motive was, as he wrote to Huygens, "to relieve poverty, and to get wholesome and agreeable foods from things that we ordinarily reject as useless," his digester was also a major advance toward the steam engine, because of a totally new feature -the safety valve. This allowed Papin safely to contain pressure many times that of the atmosphere and greater than any pressure previously controlled, limited only by the strength of the cylinder.

In 1687, Papin unveiled a new invention to transmit power pneumatically, in order to develop a means of spreading industrialization to areas where water power was not available. Papin proposed erecting two sets of pumps- one set operated by a water wheel, connected by airtight pipes to another set placed in a neighboring town or suburb. Power would be transmitted by the alternate suction and pressure exerted by the first set of pumps (see Figure 3). This idea was hotly opposed in the Royal Society, and Papin left England to accept a chair of mathematics at the University of Marburg in Hesse, bordering Hanover.

In 1690, Papin published an historic article in the Acta Eruditorum of Leipsig, "A New Method of Obtaining Very Great Moving Powers at Small Cost," where he proposed using the power of expanding steam to operate a piston/cylinder engine. In the new invention, steam replaced the gunpowder charge of Huygens's cylinder, creating a more complete vacuum under the piston, and thereby taking advantage of the full force of atmospheric pressure (Figure 4).

Papin's concept was appropriated in toto in the Newcomen engine more than 20 years later. However, although Papin mentioned in passing the utility of his invention to "draw water or ore from mines," his article featured a lengthy and detailed discussion of the application of steam power to propelling ships equipped with paddlewheels:

"So, no doubt, oars fixed into an axis could be most conveniently driven round by my tubes, by having the rods of the pistons fitted with teeth, which would force round small wheels, toothed in like manner, fastened to the axis of the paddles. It would only be requisite that three or four tubes should be applied to the same axis, by which means its motion could be continued without interruption." [Figure 5]. Papin recognized the problem inherent in such atmospheric engines. Since the source of power is not the steam itself, but the pressure of the atmosphere, the only means of increasing power is to increase the diameter of the cylinders: The principal difficulty, therefore, consists in finding the manufactory for easily making very large tubes.... And for preparing that, this new machine ought to supply no small inducement, in as much as it very clearly shows that such very large tubes can be most advantageously employed for several important purposes.