Chap. i8. ^TrettifetfftODIES. 



ciflern, but fuffcreth it felfto be lifted up, and drained away as 

 ific run deeply downwards.And they imagine, that hence may 

 be deduced, that the parts of water in the ciftern do not weigh 

 as long as they are within the orb of their own body. 

 Unto who we anfwer; that they fhould eonfider how that to 

 have the greater quantity of water, which is in the longer arm 

 of the fyphon (which arm is irarnerfed in the water ofthc ci- 

 ftern)to draw back into the ciftern the water which is in the 

 other arm of the fyphon that hangeth out in the airc ; it muft, 

 both raife as much of the water of the ciftern as its own bulk is, 

 above the levcll which at prcfent the whole bulk of water hath; 

 and withall it muft at the fame time pull up the water which is 

 in the other arm. Now it is manifeft that theft two quantities 

 of water together, arc heavier then the water in the funk arm 

 of the fyphon ; fince one of them finglc, is equall unto it. And 

 by confequence, the more water in the funk arm cannot weigh 

 back the lefle water in the hanging arm j fince that, to do thac, 

 it muft at the fame time weigh up over and above, as much 

 more in the ciftern as it (elf weigheth. 



But turning the argument ; I fay, that if once the arm of the 

 fyphon that is in the aire, be fuppofed to draw any water, be it 

 never fb little, out ofthe ciftern ( whether occafioncd by fuck- 

 ing or by whatfoever other means ) it followech that as much 

 water as is drawn up, above thelevell ofthc whole bulk in the 

 ciftern, muft needs prefle into the funcken arm from the next 

 adjacent parts, (that is,fromthe bottom)to fupply its emptying; 

 and as much muft of it felf preffe down from above (according 

 to its naturall courfe, when nothing violemeth it)to reft in tbe 

 place,that the afcending water(which is lower then it)leaveth at 

 liberty for it to take pofTeffion of.And then it cannot be doubted; 

 but that, this defending water shaving all ks weight in prcffing 

 down applied to drive up the riling water in the funk arm ofthe 

 fyphon;&the water in the other arm ofthe fyphon wichout,ha- 

 ving all its weight in tuning out applied at the fame time to draw 

 up the fame water in the funk armjthis fingle refiftant muft yield 

 to their double&maftering force. And cofequently, the water in 

 the arm ofthc fypho that is in the aire/oiuft needs draw the wa- 

 ter that is in the other immerfedarm aslon^ i of its pipe 

 rcacheth lower then the leycil ofthe w*icr in the ciftern; *br fo 



