for adjujling Thermometers-. 821 
We made fome trials with the long thermometer in 
the deep pot, to determine how much the height of the 
boiling point was affected by a greater or lefs depth of 
water above the ball. By a mean of the experiments it 
flood ,66 of a degree higher when the water role 15 
inches above the ball, than when it was only three inches 
above the ball; fo that increafing the depth of water 
above the ball by 1 1 inches, raifed the thermometer ,66 
of a degree, that is ,06 for each inch. 
We would by no means infer however from hence, 
that it is a conftant rule, that the height of the boiling 
point is increafed ,06 of a degree by the addition of each 
inch in the depth of the water above the ball ; as per- 
haps the proportion would be found very different in 
greater depths of water or in wider veflels. 
If this rule is conftant, it would lhew that, when the 
preflure on that part of the water which furrounds the 
ball is increafed by increafing the depth of water above, 
the ball, the height of the boiling point is not altered 
thereby more than half as much as by an equal increafe 
of preflure produced by an alteration in the weight of 
the atmofphere : for the preflure on that part of the wa- 
ter which furrounds the ball is as much increafed by an. 
alteration of 1 1 inches in the depth of the water above 
the ball, as by an increafe of of an inch in the height 
