v. 
C 48 3 
IV. Experiments upon Heat. By Major-General Sir Benjamin 
Thompson, Knt. F.R.S. In a Letter to Sir Joseph Banks, 
Bart. P.R.S. 
Read January 19, 1792. 
DEAR SIR, Munich, June, 1787. 
Since my last communication upon the subject of heat, which 
the Royal Society have done me the honour to publish in their 
Transactions, I have made some further progress in the investi- 
gation of that most interesting subject, of which I propose to 
give you an account in this letter. 
The confining and directing of heat are objects of such vast 
importance in the oeconomy of human life, that I have been in- 
duced to confine my researches chiefly to those points, con- 
ceiving that very great advantages to mankind could not fail 
to be derived from the discovery of any new facts relative to 
these operations. 
If the laws of the communication of heat from one body to 
another were known, measures might be taken with cerfainty, 
in all cases, for confining it, and directing its operations, and 
this would not only be productive of great oeconomy in the 
articles of fuel and clothing, but would likewise greatly increase 
the comforts and conveniencies of life ; objects of which the 
philosopher should never lose sight. 
