52 Dr. Holyoke’s new Scale 
Conpertniianenennnns and if the vessel or tube, si aitepate 
contained, be small and closed, as for thermometers they must be, 
they aré subject to be burst ; or, if left open, the fluid by evaporation 
is dissipated and lost. So that beyond this boiling point no fluid can 
be a.measure of heat. Hence nature seems to have limited,.in the 
most rigorous manner, the degrees of heat, which each individual flu- 
id is apelin of ee when formed into.a thermometer. 
These being bted facts, it follows, that the most natural point, 
at whith to fix the zero, is precisely that, at which the fluid employed 
just begins to lose its fluidity, and to put on the form ofa solid. And 
the most natural point, at which to terminate the scale, is that, at which 
it just begins to boil, or at which it ceases to-be a measure. | 
pose it would occur to every one engaged in constructing anew scale. 
But unhappily the fact, that mercury, the fluid best adapted ‘to . 
thermometrical purposes, was capable of congelation, was unknown. 
at the time, that Messrs. Fahrenheit and Reaumur adjusted their 
scales to the thermometer ; otherwise it is probable they would have 
proceeded upon a very different plan. ‘These two scales have been 
for some time and still are the most approved and employed in Eu- 
rope; the former in England and the more northern parts, and the 
latter in France and perhaps the more southern. These are therefore, 
I suppose, as little liable to. objections, as any. “But they both fall 
much short of that perfection, which it were to be wished so useful 
an instrument were possessed iat or as:the present improved state of 
philosophy and philosophical instruments seems to demand. 
Fahecshait hoginehisctale-stebiateat arbitrary manner, and un- 
luckily has pitched upon a point by much too high; so that whenever 
the cold is so great asto reduce the mercury below Oon his scale, which 
happens every winter with us in North America, there is a necessity 
