5 1 6 Comlujlion ef GunpoiviJu't 



fcrecns of very tliin paper, one behind another, nt the diftance of 12 inches from each other \ 

 nad loading a common niufkct re])eatedly with this po\i der, fometimes without and fome- 

 timci with a wad, he fired it againft the foremoil fcrcen, and obfcrved the quantity and ef- 

 fcclsof the unconfumed grains of powder which impinged againft it. 



T he fcrecns were fo contrived, by means of double frames united by hinges, that the pa- 

 per could be changed with very little trouble, and it was adually changed after every expe- 

 riment. 



The diftance from the muzzle of the gun to the lirft fcrecn was not always the fame ; in 

 fopie of tlic txperiroents it was only 8 feet, in others it was lo, and in fomc 12 feet. 



The charge of powder was varied in a great number of difFercnt ways ; but the moft in- 

 tcrefting experiments were made with one fingle large grain of powder, propelled by fmallcr 

 and larger charges of very fine grained powder. 



Thefe large grains never failed to reach the fcreen ; and though they fometimes appeared 

 to have been broken into fcveral pieces by the. force of the explofion, yet they frequently 

 reached tlie fcreen entire ; and fometimes palTed through all the fcreens (five in number) 

 without being broken. 



When they were propelled by large charges, and confequently with great velocityj they 

 were fcldom on fire when they arrived at the firft fcreen, which was evident not only from 

 their not fetting fire to the paper (which they fometimes did), but alfo from their being 

 found fticking in a foft board, againft wlilch they ftruck, after having palTed through all the 

 five fcreens ; or leaving vifible marks of their having been impinged againft it, and being 

 broken to pieces and difperfed by the blow. Thefe pieces were often found lying on the 

 ground ; and from their forms and dimenfions, as well as from other appearances, it was of- 

 ten quite evident that the little globe of powder had been on fire, and that its diameter had 

 been diminifhed by the combuftion before the fire was put out, on the globe being projedcd 

 into the cold atmofphere. The holes made in the fcreen by the little globe in its paflage 

 through them, feemed alfo to indicate that its diameter had been diminlftied. 



That thefe globes or large grains of powder were always fet on fire by the combuftion of 

 the charge, can hardly be doubted. This certainly happened in many of the experiments ; 

 for they arrived at the fcrecns on fire, and fet fire to the paper : and in the experiments in 

 which they were projeded with fmall velocities, they vi-ere often feen to pafs through the 

 air on fire; and when this was the cafe, no veftige was to be found. 



Tlicy fometimes paiTed on fire through feveral of the forcmoft fcreens M-ithout fetting 

 them on fire, and fet fire to one or more of the hindmoft, and then went on and im- 

 pinged againft the board, which was placed at the diftance of 12 inches behind llie laft 

 fcreen. 



The Count then proceeds to mention another experiment, in which the progreftivc com- 

 buftion of gunpowder wrts ftiewn in a manner ftill more ftriklng and not lefs conclufive. 



A fmall piece of red-hot iron being dropped down into the chamber of a common horfe- 

 plftol, and the piftol being elevated to an angle of about .45 degrees, upon dropping down 

 into its barrel, one of the fmall globes of powder (of the fize of a pea), it took fire, and was 

 projc(fled into the atmofphere by the elaftic fluid generated in its own combuftion, leaving 

 a very beautiful train of light behind it, and dlfappcaring all at once like a f.illing ftar. 



This amufing experiment was repeated very often, and with globes of difierent fizcs. 



When 



