Experiments upon Heat, 279 
meter, with an opening in the bottom of it correfponding 
with the bore of the tube, and equal to it in diameter, leaving 
to the opening a neck or fhort tube, about an inch or three- 
quarters of an inch in length. Having a thermometer pre- 
pared, whofe bulb was juft half an inch in diameter, and 
whofe freezing point fell at about 2% inches above its bulb, I 
graduated its tube according to Reaumur’s fcale, beginning at 
o°, and marking that point, and alfo every tenth degree above 
it to 8o°, with threads of fine filk bound round it, which 
being moiftened with lac varnifh adhered firmly to the tube. 
This thermometer I introduced into the glafs cylinder and 
globe juft defcribed, by the opening in the bottom of the 
globe, having firft cboaked the cylinder at about 2 inches from 
its junction with the globe by heating it, and crowding its fides 
inwards towards its axis, leaving only an opening fufficient to 
admit the tube of the thermometer. The thermometer being 
introduced into the cylinder in fuch a manner that the center 
of its bulb coincided with the center of the globe, I marked a 
place in the cylinder, about three-quarters of an inch above 
the 80th degree or boiling point upon the tube of the inclofed 
thermometer, and taking out the thermometer, I choaked the 
cylinder again in this place. Introducing now the thermometer 
for the laft time, I clofed the opening at the bottom of the 
globe at the lamp, taking care, before 1 brought it to the fire, 
to turn the cylinder upfide down, and to let the bulb of the 
thermometer fall into the cylinder till it refted upon the lower 
choak in the cylinder. By this means the bulb of the thermo- 
meter was removed more than 3 inches from the flame of the 
lamp. The opening at the bottom of the globe being now 
clofed, and the bulb of the thermometer being fuffered to 
return into the globe, the end of the cylinder was cut off to 
4 within 
