126 Professor Adams on the Theory of the Thermometer. 
and diminished by condensation, and if tiis is the case, the 
additions of equa! quantities of heat will give smaller incre- 
ments of teniperature at high than at low degrees, which 
must to a certain extent render the thermometer inaccurate 
in higher degrees, though probably only to a very small 
extent, of little importance as to ail practical purposes; and 
this cause of inaccuracy appears to be counteracted by 
another, that fluids seem to be more expansible by heat in 
proportion as their temperature is higher.*” 
{any other similar quotations might be made from the 
most distinguished late writers, were it deemed necessary. 
It is not my design to examine separately those which have 
been produced. The wide discordance of the results must 
be seen upon the shigbsest —— It is also sufficient- 
ly apparent, that there has been much loose = ae 
has neralization, and erroneous reasoning, a 
great departure from the cautious spirit of ie Baconian 
philosophy on this subject. “ Aliquando dormitat bonus 
Homerus.” If the thermometer is to be graduated ac- 
cording to any of the preceding conclusions, whose _— 
shall be preferred? But it is believed, it will appear fro 
the following remarks upon the preceding quotations, sat 
the construction of the thermometer has no connection with 
hypothetica! considerations, but that it is founded upon 
facts 1° + SRW in their nature, and ascertained without 
difficulty. 
First, then, the thermometer viewed as the measurer of 
temperature, is, like other standards of measurement, a an in- 
strument of a conventional nature; its construction always 
has been, and must be founded upon facts, and must in no 
degree be connected with hypothetical considerations. A 
different — of facts have, it is true, since the invention 
and by differences of ———* different degrees of en- 
ergy in the action of this cause. The thermometer in ifs 
indications, gives merely affereices of temperature. 
* Elements, p. 51. 
