Force of Steam. 13 
again, and will remain so until the tempera- 
ture is still further increased to the necessary 
point specified in the table. 
JOHN SHARPE, 
January, 1806. ‘ 
I have subjoined the following Note, received from Mr. 
Darron, which, I apprehend, will require no apology. 
Oct. 1810: 
There are but three opinions, which can be entertained as 
at all probable on the subject of the force of steam, in con- 
tact with water, in high temperatures. Ist. Steam, over 
water of 252°, may be of the same density as that over watex 
of 212°, and the great increase of force may arise from the 
increase of temperature solely. In this case, the application 
of steam for mechanical purposes would be much more econo- 
mical, in regard to expenditure of fuel, at a high temperature. 
2d. Steam, over water of 252°, may be of the same density 
as that over water of 212°, and the great increase of force 
may arise from its having combined with double the quantity 
of latent heat (as it has been called.) In this case, there 
would be no advantage in using high temperatures, except 
that less water would be requisite ; and the precediug ex- 
periments on distillation would have abundantly manifested 
the truth of the supposition, by giving a much greater in- 
crease of temperature in the water condensing the steam of 
high temperature than in that condensing the lower. The 
experiments, therefore, shew the fallacy: of this supposition. 
3d. Steam, over water of 252°, may be of double density, 
compared with that over water of 212°,"and the increase of 
4 
