, 822 Report of the Committee 
of the barometer; and fuch an alteration in the height 
of the bai'ometer is fufheient to raife the boiling point 
1 °» 3 * 
It feems as if the height of the boiling point was in 
•fome meafure increafed by having a great depth of wa- 
ter below the ball, as in general the fhort thermometers 
flood higher when tried in the deep pot than in the fhort 
one; this effeft, however, did not always take place. In 
the former of thefe cafes, the depth of water below the 
ball was about 18 inches, in the other only 4; but the 
depth of water above the ball was the fame in both 
cafes. 
It muft be obferved, that when there was a great 
depth of water in the veffel, either above or below the 
ball, the experiments were much more irregular, and the 
quickfilver in the tube remained much lefs heady than 
when it was fmall. When the depth of water in the 
veffel is great, it is apt to boil in gufts, which feems to 
be the caufe of this irregularity; though we could not 
perceive any regular connexion between thefe gufts and 
the riling of the thermometer. 
In the experiments made with the water not riling fo 
high as the ball, fo that the thermometer was expofed 
only to the fleam, we very feldom found any fenlible 
difference whether the water boiled fall or flow: but 
whenever 
