518 On Heat & Cold produced by Mechanical 
thermometer seemed very well to accord with 
the supposition of great heat or cold acting upon 
it for a few seconds only. 
EXPERIMENT 2, 
Pursuing this idea I imagined that if two 
thermometers whose bulbs were very unequal in 
magnitude were inclosed together, the smaller 
bulb ought to give the greater variation: ac- 
cordingly I inclosed two, the diameters of their 
bulbs being .35 and .65 of an inch respectively ; 
and having exhausted the air and restored it | 
again repeatedly in succession, and found a 
mean of the variations, that of the small bulb 
was 2°, 8, and that of the large, 2° 2. 
EXPERIMENT 3. 
Repeated the exhaustion with the small ther- 
mometer inclosed in three different circum- 
Stances successively; ast with. the bulb in the 
centre of the receiver; ed with the bulb resting 
on the wet leather of the plate; and 3d with the 
bulb resting against the side of the receiver. 
ist Case—Reduced by exhaustion .........+. 2°.45 
OE) Cast cacctstaccuniotenies pant nan endsunes sauuuncusyaehiwas 2.15 
BEL Rea cc sh nai sakuteleatned canna nng eae 1.2 
ist Case—Raised by restoring the air .--..... 4 .O5 
Ee ARC ree desccaned, PME taal oes. Ea aD 2.25 
gd Case— «21 avanvssnassnuanens nnsventarns aensaanssnessareD, 4O 
