¢ a excited 
276 Watson on the Heat produced by Friction. 
apparatus, the air would pass through the passage De 
and be totally expelled; now turn the stop cock one quar- 
ter round and the communication between the air and the 
globe would be cut off, but that between the receiver and 
the globe through C would be opened, and as the 
mercury fell to its level, the air in the receiver would 
be rarefied ; restore the stop-cock to its onginal posities : 
Art. XVI[.—On the cause of the heat Saas by friction; ; 
by James T. Wat 
TO THE EDITOR, 
Dear Sir, 
288 
an account of which I 
tnished sir-pumps 
ents, 
A wooden eee was Gtted to a socket, and a similar 
sole also fitted toa socket within the receiver ee an air- 
I nave made some attempts to explain the cause ithe 
by fric 
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