Improved Pressure Engine from Belidor.

355

Chap. 9.]

tween C and the lower part of A, upon which the piston descends in thecylinder and the foul water in C escapes through the lower end of A andruns to waste. By the time the piston reaches the bottom of the cylinder,the latter is refilled with water by the pressure of the atmosphere, as in acommon pump ; and the contents of Gr have escaped through an orificein its bottom, which is closed by a valve—this valve being opened bya projecting pin upon which the vessel descended, as shown in the figure.As soon as Gr is emptied, the weight on the opposite end of the rod prepon-derates, and turns the plug of the cock into its former position; and thusthe play of the machine is continued without intermission. The Operationof filling the cylinder through the funnel, is required only at the first, likethe priming of a new pump.

The origin of this machine is uncertain. It does not appear to havebeen invented by Fludd himself, but is inserted among others, which hecopied from' older authors; and such as he examined abroad. As he tra-veled in Germany and has described some of the hydraulic machinesused in the mines there, (see one figured on page 219,) it is probable thathe derived a knowledge of it in that country. It possesses considerableinterest—it is seif acting, and that by a very simple device—it shows an oldapplication of the three-way cock—it exhibits the application of refuse orputrid water, to raise fresh, and in a way sonaewhat similar to one re-cently proposed—and it is the oldest piston pressure engine known.

The next figure from Belidor , shows a great improvement on the last,so mueh so, that in some respects it may he considered a new machine.

A, conveys the descendingcölumn from its source to thethree-way cock F ; to one ofthe openings of which it isUnited. Thi's cock is con-nected, at another opening,to the horizontal cylinder C,whose axis coincides withthat of a smaller one D. Bothcylinders are of the samelength; and their pistons areattached to a common rod, asrepresented. Two valves areplaced in the ascending pipeB—one below, the otherabove its junction with thecylinder D. The horizontalpipe H connects B and D with the third opening of the cock. By turningthe plug of this cock, a communication is opened alternately between eachcylinder and’ the water in A. Thus when the water rushes into C, itdrives the piston before it to the extremity of the cylinder, and conse-quently the water that was previously in D is forced up the ascendingpipe B ; then‘ the communication between A and C is cut off, (by turn-ing the cock) and that between A and D is opened, when the pistonsare moved back towards F by the pressure of the column against thesmaller piston—the water previously in C escaping through an openingshown in front of the cock and runs to waste, while that which enters Dis necessarily forced up B at the next stroke of the pistons. The cockwas opened and closed by levers, connected to the middle of the pistonrod, and was thus worked by the machine itself. By the air chamber,the discharge from B is rendered eontinuous.

No. 161. Pressure Engine from'Belidor. A. D. 1739.