for the mercurial Thermometer. 53 
tween 100 and 350 be divided into 250 equal parts or degrees ; and 
let 100 of those degrees be set off downwards from the freezing 
point, marked 100 on the scale ; and let that point be marked 0, which 
will be as determinate and as exact, as if the same point were ad- 
justed from the actual freezing of mercury ; provided the tube be of 
an exactly equable bore throughout, and that mercury freezes at ex- 
- actly 40° below 0, by Fahrenheit’s | scale ; which by the _exper- 
iments made at Hudson’s Bay and reported in the philosophical trans- 
actions, seems to be the truth, or at furthest within one degree of it. 
Having thus found the two points, at which mercury and wa- 
ter freeze, and. divided the interval into one hundred degrees, 
let the scale then be continued on, in divisions of the same extent, 
till. we arrive at the point, at which quicksilver boils. This point is 
said to be 656 by Fahrenheit’s scale, which is equal by our new scale — 
to 962,5. Here then the scale must terminate, as at this point mer- 
cury loses its thermometrical capacity. | 
One hundred degrees of the proposed scale will then be just equal 
to 72 degrees of Fahrenheit, apd. es to 32 comes of a S 
scale in extent. 
The more noted points of the Thermometer will then stand as 
follows, i in Mas ere aie scales. 
oad 
New scale. | Fahrenheit. | Reaumur. 
Quicksilver freezes'at <ooe Aap peloop a 4 f+ $2) 
Fahrenheit’s scale be ee 55,55 O — 14,2 
Water freezes, and aioraiotee s scale begin 100 a To 
sali " 191,66 98. } + 29,34 
= as of wine boils - - - 291,7 +170 | + 61,28 
ater boils - ot AEE 350 + 212 |+80 ~ 
Melted Tin fixes -  .. - i 666,66 |. + 442 | + 182,22 
Melted Lead fixes - oe 904,54 | +612 | + 257,77 
Quicksilver and linseed oil boil - 962,5 | + 656 | + 277,33 
A scale thus adjusted to a mercurial Thermometer is capable of 
os tae degree of heat, of which mercury can be a meas- 
"The divisions appear natural, and the degrees are so minute as 
