on ignited Bodies .. $ T r 
April 29, 1776, I heated a cylinder of wrought 
iron, which weighed fifty-five pounds, to a white 
heat, and exa&ly balanced the fame, when hot, in the 
prefence of the hon. henry cavendish, nath.piggot, 
MATTHEW RAPER, ANDREW CROSBY, EDW. DELAVAL, 
HAMILTON, DAVID HARTLEY, WILLIAM RUSSEL, 
Efquires; Doctors hunter, brocklesby, morton, 
WILLIAM FORDYCE, GEORGE FORDYCE, RUSSEL, WATSON 
junior, musgrave ; MefT. John hunter, ben. wilson, 
JAMES’ RUSSEL, RAMSDEN, WHITEHOUSE, MAGELLAN. 
After the cylinder had been two hours cooling in the 
fcale, I weighed it again, and found that it had increafed 
in weight three pennyweights and a few grains... Five 
hours after cooling, Mr. Magellan weighed it, and 
found it had increafed in weight three pennyweights 
feventeen grains. Six hours after cooling, when the 
cylinder was blood- warm, I weighed it again, in the pre- 
fence of Dr. hunter, Dr. brocklesby, Mr. gray, and 
Mr. nelsbit, and found it to have increafed in weight 
four pennyweights. The day following, about twenty- 
two hours after cooling in the prefence of matthew 
raper and Andrew crosby, efquires, I again weighed it, 
and found that it had increafed in weight fix penny- 
weights feventeen grains. Mr. abram whitehouse, 
who was very folicitous. to have the above experiment 
made accurately, procured from Mr. samuel read a 
very exact beam, which readily turned, to the conviction 
;©f all the above gentlemen, with lefs than a penny- 
weight, though loaded with the above iron cylinder; but 
mat tile w raper, Andrew crosby, Efquires, and my- 
felf 
