g 8 Count Rumford’s Enquiry concerning the Nature of Heat , 
The whole of the metallic surface exposed to the air, in the 
experiments made with the instrument when it was quite naked, 
amounted to 85.155 superficial inches; namely; 
Surface of its vertical sides 
of its lower end 
of its upper end 
of its neck 
= 50.136 inches. 
= 12.755 
- = 12.253 
= 10.051 
Total surface = 85.135 inches. 
When the instrument was exposed quite naked to the air, it 
was found to cool through the standard interval of 10 degrees, 
in 45! minutes. 
Assuming now any given number, as the measure of the 
whole quantity of heat given off by the instrument during the 
period above-mentioned, we can ascertain what part or pro- 
portion of that quantity passed off through the sides of the 
instrument; and what part of it must have made its escape 
through its ends, and through the sides of its neck. 
As the quantities of heat given off are supposed to have been 
as the quantities of surface exposed to the air, if we suppose the 
whole quantity of heat lost by the instrument to be = 10000 
parts, the quantity which passed through the vertical sides of 
the instrument in 45^- minutes, in the experiment, must have 
amounted to 5885 parts. For, the whole of the surface of the 
instrument, = 85. 135 superficial inches, is to the whole of the 
heat given off, = 10000, as the surface of the vertical sides of 
the instrument, = 50.13 6 superficial inches, to the quantity of 
heat which must have passed off through that surface in the 
given time, =5885. 
Now, as we may with safety conclude, that the quantity of 
