C 80 3 
IV. An Inquiry concerning the Source of the Heat which is 
excited by Friction . By Benjamin Count of Rumford, 
F.R.S. M. R. I. A. 
Read January 25, 1798. 
It frequently happens, that in the ordinary affairs and occupa- 
tions of life, opportunities present themselves of contemplating 
some of the most curious operations of nature ; and very interest- 
ing philosophical experiments might often be made, almost with- 
out trouble or expence, by means of machinery contrived for 
the mere mechanical purposes of the arts and manufactures. 
I have frequently had occasion to make this observation ; and 
am persuaded, that a habit of keeping the eyes open to every 
thing that is going on in the ordinary course of the business 
of life has oftener led, as it were by accident, or in the play- 
ful excursions of the imagination, put into action by contem- 
plating the most common appearances, to useful doubts, and 
sensible schemes for investigation and improvement, than all 
the more intense meditations of philosophers, in the hours ex- 
pressly set apart for study. 
It was by accident that I was led to make the experiments 
of which I am about to give an account ; and, though they are 
not perhaps of sufficient importance to merit so formal an in- 
troduction, I cannot help flattering myself that they will be 
thought curious in several respects, and worthy of the honour 
of being made known to the Royal Society. 
