Ram Siphon.

531

Chap. 6.]

would then be the same äs the siphon for raising water which Gravesandebas figured in the second volume of his Philosophy, p. 39, plate 74.

The best of these devices are not only subject to derangement by thewear of the cocks and valves, and want of care in opening and closing themat the proper times, but they require almost as much attendance as wouldsuffice to raise the water directly from the spring. On this account variouscontrivances have been proposed to render them self-actfng.

An ingenious device of this kind may be seen in the Gentleman’s Ma-gazine for 1747, p. 582. It is named a “ lifting siphon.” Water from aspring is received into an open cistern, from the bottom of which a pipedescends to a perpendicular depth of 33 feet. The bore of this pipe isclosed and opened by two stop-cocks, one at its lower end and the othernear the upper, or just below its junction with the cistern. A closevessel to receive the water raised is to be fixed at any required elevation,not exceeding 30 feet above the cistern ; and from its bottom a pipedescends to within two inches of the bottom of the cistern. This pipeconstitutes the short leg of the siphon, and its upper orifice is covered bya valve to prevent the water that ascends through it from returning. Frcmthe top of the close vessel a small or exhausting pipe proceeds down tothe one beneath the cistern and is connected to it below the upper cock.Thus United they may be considered as the long leg of the siphon, al-though water only descends through the lower branch and air through theupper one. The apparatus for alternately opening and closing the cocks(upon which the action of the machine depends) is somewhat similar inprinciple to that represented at page 354. A bücket containing water isthe prime mover ; a rope attached to it is passed twice round two rollers,and a counterpoise is suspended from the other end of the rope. Whenthe bücket is partly filled it preponderates, and when it is emptied thecounterpoise prevails ; hence an alternating movement is imparted to therollers and to the plugs of the two cocks, as the shanks of these constitutethe axles of the rollers.

A plan for making siphons of this description self-acting by means offour vessels placed one over the other, and each provided with a siphonby which its contents may be discharged, was proposed by Mr. Wm.Close, in Nicholson’s Journal before referred to.

M. Hachette has combined the ramof Montgolfier with the siphon, in Orderto discharge water from the apex of thelatter : see the annexed figure. A theshort leg and E. the long or discharg-ing one. The upper end of each termi-nates in a close chamber within whichtwo valves attached to a perpendicularrod äre made to Work. The uppervalve closes an opening in the horizon-tal partition that separates the interiorof the chamber from the air-vessel andjet pipe above. The seat of the lowervalve is at the orifice of R. The dis-tance between the valves is such thatwhen one is closed the other is open.Their movements are produced as inthe ram ; a coiled spring keeps theupper one closed tili the momentum ofthe fluid in passing through the siphon

No. 270. Ram siphon.