[ 94 ] 
The ftopper was now put in. 
\ 
6 - - 292 - 368 
7 = a - 63 
Bes - 409,5 = 5455 
9 P WA EALHBIO RY HILARY 07 HBG 
Io t Ss 500 = 42 
—— 244 in 5° 
Ir is obvious that the effect of the ftopper in increafing the 
heat muft have been confiderable, as, from the former part of the 
obfervation, it appears, that as the temperature of mercury en- 
creafes, the increments of its temperature in a given time (circum- 
ftances remaining the fame) diminifh. Yet the fum of the incre- 
ments in the laft five minutes confiderably exceeds the fum of the 
increments in the firft. We now wifhed to try the effe&t of dimi- 
nifhing ftill farther the internal air aperture of the wick-holder, 
and for this purpofe adapted to the ftopper a ring, which encreafed 
its diameter to Zths of an inch, and confequently diminifhed the 
width of the circular opening for air to ;3,ths of an inch. 
Tue following table will fhew the effedt of this alteration. In 
this experiment the lamp burned lefs brifkly than in the former. 
The 
* The increment of temperature in the 6th minute was diminifhed by lowering 
the flide for the admifion of the ftopper. 
