JET. 30-40.] COUNT RUMFOED. 39 



particularly of such substances as are used for clothing, 

 he made experiments on the relation between their 

 conducting power and their power of absorbing moisture, 

 but found none. Flannel and fur, contrary to his 

 expectation, absorbed much more moisture from the air 

 than silk and cotton. On this he forms an idea of the- 

 good of wearing flannel. This, the weakest of his- 

 papers, was read to the Eoyal Society, March 22, 1787. 



In the spring of 1791 a large building was erected 

 in the neighbourhood of Munich, on the ground 

 destined for the exercise of the artillery, where a most 

 complete apparatus was put up for measuring the 

 velocities of cannon bullets by the recoil of the gun, and 

 also by the pendulum at the same time, and with this 

 apparatus a great number of interesting experiments, 

 were made. 



He observed that the force of the charge was 

 always sensibly increased when the gun was discharged 

 by firing a pistol (constructed for that use) into the 

 vent, instead of using a priming and a common match 

 for firing off the gun. 



These experiments were continued in 1792, and 

 in 1793 they were shown to Dr. Blagden, who was in 

 Munich during the absence of Sir B. Thompson in 

 Italy for his health. 



The principal objects in view were to determine the 

 expansive force of the elastic vapour generated in the 

 combustion of gunpowder in its various states of con- 

 densation, and to ascertain the ratio of its elasticity 

 to its density, and to measure the utmost force of this 

 fluid in its most dense state. 



