c8o 4 Sir Benjamin Thompson’s 
within about half an inch of the upper choak. This being 'done* 
it is plain, that the tube -of the thermometer projected beyond 
the end-of the cylinder. Taking hold of the end of the tube, 
I placed the bulb of t'faev thermometer as nearly as poffible in 
the center of the globe, and 'obferving and marking a point in 
the tube immediately above the upper choak of the cylinder, 1 
turned the cylinder upfide down,, and buffering the bulb of the 
thermometer to enter the cylinder, and '<reft upon the firft or 
lower choak (by which means the end -of the tube of the ther- 
mometer came further out of the cylinder), the end of the tube 
was cut off at themark juft mentioned (having firft taken care 
to melt the internal cavity or bore of the tube together at that 
place), and a fmall folid ball of glafs, a little larger than the 
internal diameter or opening of the choak, was foldered to the 
end of the tube, forming a little button or knob, which 
refting upon the upper choak of the cylinder, ferved to fuf- 
pend the thermometer in fuoh a manner that the center of its 
bulb coincided* with the center of the globe in which it was 
fhut up. The end of the cylinder above the upper choak 
being now heated and drawn out to a point, or rather being 
formed into the figure of the fruftum of a hollow cone, the 
end of it was foldered to the end <jf a barometrical tube, by the 
help of which the cavity of the cylinder and globe containing 
the thermometer was completely voided of air with mercury ; 
when, the end of the cylinder being hermetically fealed, the 
barometrical tube was detached from it with a file, and the 
thermometer was left completely fliut up in a Torricellian va- 
cuum, the center of the bulb of the thermometer being con- 
fined in the center of the glafs globe, without touching it in 
any part, by means of the two choaks in the cylinder, and 
the button upon the end of the tube. 
2 
Of 
