( 310 V 



before mentioned air to be in its natural Hate, that which came out 

 of the water could not occupy a larger fpace than from P to F. Now 

 the diameter or bore of the fmall tube DEC, being only one fixth 

 part that of the larger tube B C, the bore of the larger tube is 

 thirty-fix times the fize of the fmaller one, as before has been men- 

 tioned. 



The water in the larger tube from B to C, flood at the height of 

 twelve inches, but I will only fuppofe it eleven inches, and, reck- 

 oning from this, I compute that all the air bubbles difperfcd 

 through large coUeftions of water, and extracted from it, do not 

 amount to one two hundred and fiftieth part of the bulk of the wa- 

 ter. And upon another computation made by me, I found that 

 the bubbles of air extracted from the water did not amount to one 

 two hundred and eightieth part of the water. 



After this, I took boiled water and treated it in the fame manner 

 T have dcfcribed as to rain water, but after thrice repeating my 

 experiments, I could not pump out or extract any air from it ; 

 though, indeed, I once law a fingle bubble arife, but this, I rather 

 concluded to have found its way through fome inequality in the 

 glafs, or from Ibme water not boiled, which by ^accident was in the 

 tube before the boiled water was put in. 



But becaufe many people may think that, in my experiments, I 

 could apply very little force in glafs tubes, in proportion to what 

 may be done by others with larger tubes, pumps, or Ijringes, I 

 think it right to demonlirate how much force I could apply in my 

 tube. 



We will then take the diameter of the pifton, or bore of the tube. 

 <iO be the feventh part of an inch, and fuppoling that with this pif- 

 ton, I could apply a force equal to ten pounds AAcight, the conclu- 

 fion is, that in a pump or fyringe of an inch bore, a proportionable 

 power muft be applied, which we fliall find muil be equal to four 

 hundred and ninety pounds, becaufe the pill:on of this pump or 

 fyringe is forty-nine times larger than the other ; and if the bore 



