112 PHILOSOPHICAL TRANSACTIONS. [ANNO 1781. 



exactly counterpoised by weights put in the opposite scale, it was filled first with 

 government powder poured in lightly, then with the same powder shaken well 

 together, afterwards with powder and water together, and lastly with water alone, 

 and in each case the contents of the bucket were very exactly weighed. The 

 specific gravity of gunpowder, as determined from these experiments, is as 

 follows : 



Specific gravity of rain water 1 .000 



Government powder, as it lies light in a heap, mixed with air. . 0.836 



Government powder well shaken together O.937 



The solid substance of the powder 1 .745 



Hence it appears, that a cubic inch of government powder, shaken well 

 together, weighs just 243 grains ; that a cubic inch of solid powder would 

 weigh 442 grains ; and consequently that the interstices between the particles of 

 the powder, as it is grained for use, are nearly as great as the spaces which those 



particles occupy. 



MISCELLANEOUS EXPERIMENTS. 



Of some unsuccessful attempts to increase the force of gunpowder. — It has 

 been supposed by many, that the force of steam is even greater than that of gun- 

 powder ; and that if a quantity of water, confined in the chamber of a gun, 

 could at once be rarefied into steam, it would impel a bullet with prodigious 

 velocity. Several attempts have been made to shoot bullets in this manner ; but 

 Mr. T. knew of none that had succeeded ; at least so far as to render it probable 

 that water can ever be substituted instead of gunpowder for military purposes, as 

 some have imagined. The great difficulty that attends making these experiments 

 lies in finding out a method by which the water can at once be rarefied, and 

 converted into elastic steam. Mr. T. contrived a method for this purpose, which 

 was by filling with water the thin air-bladders of very small fishes, and inclosing 

 them in the middle of cartridges of gunpowder, and then firing them ; but he 

 constantly found, that the force of the charge was very sensibly diminished by 

 the addition of the globule of water, and the larger the quantity of water was 

 that was thus confined, the less was the effect of the charge ; neither the recoil 

 of the pistol, nor the penetration of the bullet, being near equal to what they 

 were when the given quantity of powder was fired without the water ; and the 

 report of the explosion appeared to be lessened in a still greater proportion than 

 the recoil or penetration. 



Concluding that this diminution of the force of the charge arose from the 

 bursting of the little bladder, and the dispersion of the water among the powder 

 before it was all inflamed, by which a great part of it was prevented from taking 

 fire, Mr. T. repeated the experiments with highly rectified spirits of wine instead 

 of water ; but the result was nearly the same as before: the force of the charge 



