3 1 ^ ^ Attempt to make a Thermometer ' 
XI. The life and accuracy of tins thermometer for mea- 
Turing, after an operation, the degree of heat which the matter 
has undergone, will be apparent. The foregoing properties 
afford means of meafuring it alfo, eafily and expeditioufly, 
during the operation , fo that we may know when the fire is, in- 
creafed to any degree previoufly determined upon. The piece 
may be taken out of the fire in any period of the procefs, and 
dropped immediately into water, fo as to be fit for meafuring 
by the gage in a .few feconds of time. At the lame infant, 
another piece may be introduced into the place of the former, 
to be taken out and meafured in its turn ; and thus alternately, 
till the defired degree of heat is obtained. But as the cold 
piece will be two or three minutes in receiving the full heat, 
and correfponding contra&ion ; to avoid this lofs of time, it 
may be proper, on fome occafions, to have two or more pieces, 
according to convenience, put in together at firff, that they 
may be fucceffively cooled in water, and the degrees of heat 
examined at fhorter intervals. It will be unneceflary to fay 
any thing further upon precautions or procedures which the 
very idea ot a thermometer muff fuggeft, and in which it is 
not apprehended that any difficulty can occur, which every 
experimenter will not readily find means to obviate. 
XII. It now only remains, that the language of this new 
theimometei be underffood, and that it may be known what 
the heats meant by its degrees really are. For this purpofe a 
gieat number ot experiments has been made, from which the 
following refults are fele&ed. 
The fcale commences at a red-heat, fully vifible in day- 
light ; and the greatefi; heat that I have hitherto obtained in 
my experiments is 1 6 o°. This degree I have produced in an 
air-furnace about eight inches fquare. 
3 Mr. 
