VOL. LXVII.] 



PHILOSOPHICAL TKANSACTIONS. 



269 



of hot liquors, in which it would be difficult to prevent the quicksilver in the 

 tube from being heated by the steam, as it is in finding the heat of liquors with 

 the other thermometer, whenever the ball is not immersed to a sufficient depth; 

 so that, on the whole, the former method of making and using thermometers 

 seems much the best. 



A much better way, of avoiding the trouble of making a correction, would 

 be to have 2 sets of divisions made to such thermometers as are intended for try- 

 ing the heat of liquors; one of which should be used when the tube is immersed 

 almost to the top of the column of quicksilver; and the other, when not much 

 more than the ball is immersed, in which last case the observer should be careful 

 that the tube should be as little heated by the steam of the liquor as conveniently 

 can be. It is difficult to give rules for constructing this id set of divisions, as 

 the heat of the quicksilver in the tube will be very different acconling to the 

 temper of the air in the room, the quantity and nature of the fluid whose heat 

 is to be tried, the manner in which it is heated, and the other circumstances of 

 the experiment; but, on the whole, we think that which is given in the following 

 table would be as proper as any. 



To make use of this table, seek in the uppermost horizontal line the degree 

 of the thermometer answering to that point of the tube which is 2 inches above 

 the ball ; and in the left-hand column seek the degrees of the 2d set of divisions; 

 the corresponding numbers in the table are the corresponding degrees of tlie 1st 

 set, or the degrees which they nmstbe set opposite to. The right-hand perpen- 

 dicular column shows the heat which the quicksilver in the tube was supposed to 

 be of in forming this table. Though this 2d set of divisions be far from accurate. 



