12 An Inquiry concerning 



This being done, the bottles were all removed into a 

 room in which the air was at 30, where they were suf- 

 fered to remain, perfectly at rest and undisturbed, forty- 

 eight hours ; the bottles A and B being suspended to 

 the arms of the balance, and the bottle C suspended, at 

 an equal height, to the arm of a stand constructed for 

 that purpose, and placed as near the balance as possible, 

 and a very sensible thermometer suspended by the side 

 of it. 



At the end of forty-eight hours, during which time 

 the apparatus was left in this situation, I entered the 

 room, opening the door very gently for fear of dis- 

 turbing the balance ; when I had the pleasure to find 

 the three thermometers, viz. that in the bottle A, 

 which was now inclosed in a solid cake of ice, that 

 in the bottle B, and that suspended in the open air 

 of the room, all standing at the same point, 29 F., 

 and the bottles A and B remaining in the most perfect 

 equilibrium. 



To assure myself that the play of the balance was 

 free, I now approached it very gently, and caused it to 

 vibrate ; and I had the satisfaction to find, not only 

 that it moved with the utmost freedom, but also, when 

 its vibration ceased, that it rested precisely at the point 

 from which it had set out. 



I now removed the bottle B from the balance, and 

 put the bottle C in ts place; and I found that that 

 likewise remained of the same apparent weight as at the 

 beginning of the experiment, being in the same per- 

 fect equilibrium with the bottle A as at first. 



I afterwards removed the whole apparatus into a 

 warm room, and causing the ice in the bottle A to 

 thaw, and suffering the three bottles to remain till they 



