WATER. 



the ftop-valve fhuts ; when the contained water will in part 

 enter the air-veflel by the aftion already defcribed, and the 

 next wave will produce another ftroke. 



Momentum- Pump, or Momentum- Machine, to ra'ife Water 

 by the application of mechanical Power. — Where a fall of 

 water cannot be oht3ineA,Jlg. I. (hews an application of this 

 momentum principle, in lieu of pumps for raifing water, the 

 main-pipe being put in motion through the water by the 

 ftrength of men, or other mechanical power in default of a 

 current, as in the other cafes. 



C C is the main-pipe bent in a fpiral form round the air- 

 veffel J; it may either be made to touch it, or be kept at a 

 diftance from it, and may make one or more revolutions 

 round the faid veffel ; the whole of the main-pipe is im- 

 merfed in the external water which is to be raifed. Both 

 ends of the pipe are open to the water ; but one of them 

 has 'the ftop-valve opening inwards, which will occafionally 

 clofe it, and near this latter end, a communication is made 

 by a fide-pipe with the air-veiTel, the orifice being covered 

 by a valve opening into the veffel. The whole turns upon 

 a pivot K, at the lower end of the afcending-pipe D, which 

 fcrves as an axis, and is kept upright by a collar, in which it 

 turns, as (hewn at L. Upon this axis a toothed wheel M 

 is fixed, and is put in motion by another wheel N, turned 

 by a winch, crank, or other contrivance. 



At the top, or upper end of the afcending-pipe, the 

 water is difcharged into a trough, which furrounds it, and 

 conveys it to the place of its deftination. 



Tliis apparatus is made to raife water by a continued ro- 

 tative motion, the open end moving firft, through the water 

 which paffes out again through the other end ; but whenever, 

 by that motion, the main-pipe has attained a proper velo- 

 city, the ftop-valve fhuts fuddenly, and by the concuffion 

 the water paffes into the air-veffel, from whence the egrefs 

 of the water is prevented by the fhutting of the exit-valve. 

 The ftop-valve then opens by means of a fpring in lieu of a 

 weight, as in the former cafes, and the apparatus continuing 

 to revolve in the fame direftion, more ftrokes are made at 

 intervals proportioned to the velocity with which it moves. 

 The fpring of the ftop-valve fhould be fo regulated in force 

 as to allow the relative motion of the water in the main-pipe 

 to fhut the ftop-valve at proper intervals. The perpen- 

 dicular feftion of the main-pipe is drawn fquare, but may 

 be circular, or of any other convenient figure. A horizontal 

 feftion of it is fhewn dt. Jig. 6, with the main-pipe and the 

 air-veffel. 



In lieu of the wheel N, which produces a continued 

 rotatory motion, the machine may be made to vibrate or 

 fwing upon an axis, backwards and forwards, the limits of 

 the vibration or ftroke being determined by a detent ftriking 

 againft a ftiff fpring. In this cafe, the main-pipe (liould 

 be provided with ftop-valves at both ends, and alfo have a 

 communication at each end with the air-veffel, which open- 

 ings fhould be clofed by valves to prevent the return of the 

 water from it. Such a machine may be put in motion by 

 the following means : upon the afcending-pipe D, a double 

 pulley is fixed, round which are wound the ropes, and by 

 pulling the ends of thefe alternately, the apparatus may be 

 made to revolve in either direAion. The main-pipe and 

 the afcending-pipe being filled with water by hand or 

 olherwife, if the ropes are pulled alternately, they will 

 make the pipe move through the water with fufficient velo' 

 city to make the apparatus aft. It is found if the appa- 

 ratus makes about thirty vibrations in each minute, that it 

 will aft very completely. 



Hydraulic machines are of the greateft importance to 

 focJety, whether we look to a fupply of the firft neceffity 



for domeftic ufes, or to the advantageous ufes of neglefted 

 though valuable firft movers. Thefe machines muft, in moft 

 cafes, be modified by localities, and other circumftances ; 

 and confequently the moft ufeful praftical knowledge will 

 notconfift in any acquaintance with, one or more of the beft 

 engines, but with that great variety of happy contrivances 

 which inquiry and refleftion muft point out. We have, as 

 far as our limits permit, given all the machines which are 

 praftically ufeful, and we fhall conclude this article by 

 giving Dr. Young's catalogue of the moft important and 

 valuable writings on hydraulic engines. 



Ramelli's Colleftion of Hydraulic Machines, in French 

 and Italian, 1588, folio. 



Defcriptio Machine Hydraulics curiofae Conftrufta, 

 Joh. Georg. Faudieri, Venet. 1607. 



Bates on Art and Nature, 1635. 



Nouvelle invention de lever I'eau plus haut que la fource 

 avec quelque machines mouvantes par le moyen de I'eau, 

 &c. par Ifac de Caus, 1657. 



Jofephi Gregorii a Monte Sacr. Principia phifico-mecha- 

 nica diverfarum machinarum feu inftrumentorum pneumatics 

 ac hydraulices, Venet. 1664. 



Nouvelle Machine Hydraulique, par Francini Joum. dcs 

 S^av. 1669. 



[An account of this machine is likewife given in the 

 Architefture Hydraulique of Belidor, tom. ii. ; and in the 

 2d vol. of Defaguliers' Experimental Philofophy : in both 

 which performances many other hydraulic machines are 

 defcribed.] 



An Undertaking for raifing Water, by Sir Samuel Mcwe- 

 land. Phil. Tranf. 1674. N° 102. 



An Hydrauhc Engine. Phil. Tranf. 1675. N° 128. 



A cheap Pump, by Mr. Conyers. Phil. Tranf. 1677. 

 N°i36. 



M. de Hautfeuille, Reflexions fur quelque Machines a 

 elever les eaux, avec fa defcription d'une nouvelle pompe, 

 fans frottement, et fans pifton, &c. 1682. 



Elevation des eaux par toute forte des Machines, reduite 

 a la mefure, au poids, a la balance, par le moyen d'un nou- 

 veau pifton et corps de pompe, et d'un nouveau mouvement 

 cyclo-elliptique et rejetant I'ufage de toute forte de mani- 

 velles ordinaires, par le Chevalier Morland, 1685. 



A new Way of raifing Water, enigmatically propofed 

 by Dr. Papin. Phil. Tranf. i68y. N° 173. The folu- 

 tions by Dr. Vincent and Mr. R. A. in N° 177. 



M. du Torax, Nouvelles Machines pour epuifer I'eau 

 des foundations, qui, quoique tr^s fimples font un effet 

 furprennant, 1695. Joun. des S^av. 1695. p. 293. 



An Engine for raifing Water by the help of Fire, by 

 Mr. Thomas Savery. Phil. Tranf. 1699. N° 253. 



D. Papin nouvelle maniere pour lever I'eau par la force 

 du feu; a Caffel, 1707. 



Memoire pour la conftruftion d'urte pompe qui fourni 

 continuelment de I'eau dans le refervoir, par M. de la Hire, 

 Mem. Acad. Scien. Paris, 17 16. 



Defcription d'une machine pour elever des eaux, par M. 

 de la Faye, Mem. Acad. Scien. Paris, 1717. 



Joh. Jac. Bruckmann's und Joh. Heinr. Weber's Ele- 

 mentar-mafchine oder univerfal-mittel bey alien waffer-hebun- 

 gen. Caffel, 1-725. 



Jacob Leopold, Theatri machinarum hydraulicarum, 

 1724 et 1725. 



Joh. Frid. Weidleri traftatus de machinis hydraulicis 

 toto terrarum orbe maxirais Marlyenfi et LondinenC, &e. 

 1727. Vide Aft, erudit. Lipf. 1728. 



A Defcription of the Water-works at London-bridge, 

 by H. Beigbton, F. R. S. Phil. Tranf. 1731. N°4i7. 



K 2 An 



