WATER. 



courfes, each (hut by a fluice or pen-ftock, which can be 

 raifed and depreffed by racks, and in each of thefe courfes 

 an underlhot wheel is placed. The fourteen wheels are dif- 

 pofed in three lines acrofs the river. In the firft line, which 

 is up the ftream, there are feven wheels, in the fecond line 

 fix, and only one in the third. 



The wheels are thirty feet diameter, and five feet wide, 

 and they are all nearly the fame as follow- : the ends of the 

 axle of each wheel go beyond their bearing pieces, and are 

 bent into cranks, which make levers of two feet ; the crank 

 which is towards the mountain gives motion to a beam or 

 lever, which carries four piftons or forcers at each end, to 

 work in the barrels of as many forcing-pumps, which as the 

 wheel works alternately fuck up the water of the river, and 

 drive it up into the firft ciftern. The other crank at the 

 oppofite end of the axle gives motion to the chains, which 

 go up the hill, to work the pumps in the two elevated 

 citterns. 



Each of the fix wheels on the firft line is cor.ftrufted in 

 this manner, to give motion by one of its cranks to an 

 engine, confifting of eight forcing-pumps combined toge- 

 ther. The engine is aftuated by a lever or beam, from each 

 end of which a fquare piece of wood is fufpended, that 

 carries and direfts four piftons of forcing-pumps ; the beam 

 of the engine is put in motion from the crank of the wheel 

 by a beam or leader, which is connefted with the crank of 

 the wheel at one end, and with one arm of a regulator or 

 bent lever, whilft the other arm of this regulator is united 

 by another leader to the extremity of the beam of the 

 engine, which beam is thus made to vibrate up and down 

 and work the pumps. 



Of the fix wheels we have juft mentioned, there are five 

 which, by their oppofite cranks, give motion to the pumps 

 in the elevated ciftern of the firft lift. This is effefted by 

 means of one vertical beam or lever, and two horizontal 

 levers, which are bent, and aftuate the chains that com- 

 municate the motion ; the three levers are only to change 

 the direftion of the motion of the crank into a proper 

 d'.reftion to go up the hill. The fixth wheel, which is the 

 firft towards the dam, gives motion to a long chain that 

 goes up the hill to work the pumps of the upper ciftern. 

 The feventh wheel of the firft line is exclufively apphed to 

 move a chain, which goes to the firft ciftern, by both its 

 cranks. 



The fix wheels of the fecond line are like the five wheels 

 in the firft row, i. e. one of the cranks of each works an 

 engine of eight pumps, and the other a chain that goes to 

 the upper ciftern. 



Laftly, the fingle water-wheel, vi'hich is on the third 

 line by each of its cranks, works an engine of eight forcing- 

 pumps fixed in the river, and of itfelf fupplies one conduit- 

 pipe of eight inches and a lialf bore. 



There are then eight engines in the river, and reckoning 

 all the chains which go up the hill, they are thirteen in 

 number, including the chains that come from the fixth and 

 feventh wheels of the firft line : thefe thirteen chains afcend 

 the hill all together, and are fufpended at regular intervals 

 of twenty feet by levers, to bear them up from touching 

 the ground, which by moving on their centre admit of the 

 working of the chains. Each chain is double, that is, there 

 is a fecond chain, which is connedled to the oppofite ends of 

 the fufpi;nding levers, and each chain ferves to draw the 

 other chain back again after it has made its ftroke. Five 

 of thefe double chains are employed to aftuate levers, which 

 work thirty inverted lift-pumps fituated in a ciftern at the 

 firft lift, and which drive the water through two pipes of 

 eight and a half inches bore up to the upper lift. Tlie 



other eight double chains go ftraight on to the upper 

 ciftern. 



The feven chains of the wheels of the firft line, in going 

 along, work alfo eight fucking-pumps, placed a little below 

 the ciftern of the firft lift, becaufe in that place the water of 

 a confiderable fpring is brought by an aqueduft, and thefe 

 fame chains take up that water a fecond time by forty -nine 

 pumps, which are fituated in a feparate ciftern, at the firft 

 lift, on a level with the firft ciftern, and force it into the 

 upper refervoir, through two conduit-pipes of eight and a 

 half inches diameter, and three others of fix and a half inches 

 diameter. 



The water raifed by the feventy-nine pumps in thefe two 

 cifterns at the firft lift, difcharges itfelf into a great refer- 

 voir at the fecond lift, and thence by two conduit-pipes of 

 a foot diameter each, it runs into refervoirs of communica- 

 tion, and is diftributed into the feveral wells or little pump- 

 ciilerns of the upper ciftern, which all together contain 

 eighty-two inverted hft -pumps ; thefe force the wal^r through 

 fix conduit-pipes of eight inches and a half dianjtter up into 

 the ciftern, in thetower which anfwers to the aqueduft. Thefe 

 eighty -two lift -pumps are worked by the eight great chains 

 before mentioned, that go ftraight to the upper ciftern, 

 without moving any pumps by the way ; and the fame chains 

 work fixteen fucking-pumps behind the upper ciftern, to 

 bring back into the relervoir of the lame ciftern the water 

 which leaks out of the fix iron pipes that go to the tower. 



To fum up all the pumps of this intricate machine : 



1 . The eight engines in the river contain fixty-four pumps, 

 which fuck and force the water 1 60 feet up five iron pipes of 

 eight and a half inches bore, and 213 yards long, up to the 

 firft lift. 



2. The two cifterns at the firft lift contain feventy-nine 

 lifting-pumps, which raife the water 186 feet, through four 

 pipes of eight and a half inches bore, and three pipes of 

 fix and a half bore, and 477 yards up to the fecond lift. 



3. The cifterns at the fecond lift contain eighty-two 

 Lfting-pumps, which raife the water 189 feet through fix 

 pipes of eight and a half inches bore, diftance 640 yards : 

 In all 225 forcing-pumps, which lift 535 feet and 1330 

 yards diftance. To this muft be added eight fucking- 

 pumps in the river called feeders, which raife water into the 

 cifterns at the top of the forcing-pumps, to keep water in 

 the pumps, and prevent leakage ; alfo the eight others which 

 are below the midway ciftern ; and laftly, the fixteen fucking- 

 pumps, wliich we mentioned as placed beliind the upper 

 ciftern, fo that the machine has in all 257 pumps. 



The bafin of the tower, which receives the water raifed 

 from the river, and fupplies the aqueduft, is 1330 yards 

 diftant from the river, and 535 feet above the level: the 

 water having run along a flone aqueduft, which is raifed 

 upon thirty-fix arches, is feparated into different conduits, 

 which lead it to immenfe refervoirs at Marly, and formerly 

 conveyed it alfo to Verfailles and Trianon. 



Such is the mechanifm of the machine of Marly. Its 

 mean produce in Belidor's time was from 3000 to 4000 

 Enghfh cubic feet of water per hour : he fays mean pro- 

 duce, becaufe under certain favourable circumttances it has 

 formerly raifed more than 8484 cubic feet per hour. But 

 during inundations, or when the Seine is frozen, when the 

 water is very low, or when any repairs are making, the 

 machme ftops in a great meafure, if not entirely. 



The annual expences of the machine have been ftated 

 formerly at 3300/. fterling, or 9/. pe^ Azy, including the 

 falaries of thofe who fuperintend it, and the wages of the 

 workmen employed, together with repairs, neceffary articles, 

 ficc. This ^raakes about one farthing for every eleven 



cubic 



