270 Mr. Kir wan's Remarks on fpecijic Gravities 
In this calculation I take no account of the difference arifing 
from the expanfion of the veifel, it being only 0,067 a11 
inchat the boiling point ; for, according to Bouguer, iron is 
dilated 0,00055 of its bulk from the freezing to the boiling 
point; confequently 42,961 cubic inches gain only 0,067 an 
inch, augmenting the diameter and perpendicular height of 
this fruflum of a cone at the boiling point in that proportion. 
Hence alfo we fee, that the expanfions of water are not pro- 
portional to the degrees of heat ; for by 20 degrees of heat from 
'6 2 0 to 82° a cubic foot of water is dilated only3,i 2 inches, but by 
the -next 20 degrees of heat, that is., from 82° to 102°, it is 
expanded 5,7 inches, &c. 
Mr. Bladh found the volume of water at 32 0 to be equal 
to that at 53 0 , 6 ; but that this irregular expanfion ceafed at 36 °6, 
and, according to Mr. De Luc (who frff difcovered it) at 43 0 . 
As the expanfion of liquids by equal degrees of heat is much 
greater than that of folida, it happens, that the fpecifi c gravi- 
ties of the fame folid taken at different temperatures will be 
different:; and, what appears more extraordinary, the fame folid 
will appear fpecifcally heavier in higher than in lower tempera- 
tures ; for the fame volume of water being lighter in higher 
than in lower temperatures, the folid wilflofe dels of its weight 
in it in the former than in the latter cafe : this miftake we 
may remedy by infpedling the fifth column of the foregoing 
table and the following analogy as the weight of a .cubic inch 
of water at the temperature of 62° is to the weight of a cubic 
inch of water at n degrees of temperature, fo is the fpe.cific 
gravity found at n degrees of temperature to that which will 
be found at 62°. 
Thus, if 1000 grains of iron be weighed in water of the 
temperature of 62°, and it iofes therein 13,533 grains* ir the 
fame 
