240 Mr. Thompson’s Experiments 
thicknefs, and a cartridge capable of containing half an ounce 
of powder weighed but three quarters of a grain* 
The cartridges were formed upon a, wooden cylinder, and 
accurately fitted to the bore of the piece, and the edges of the 
paper were faflened together with paffe made of flour and water. 
When a cartridge was filled, the powder was gently fhaken 
together, and its mouth was tied up and fecured with a piece of 
fine thread ; and when it was made life of it was put in tire into 
the piece, and gently pufhed down into its place with the ram- 
rod, and afterwards it was pricked with a priming-wire thruft 
through the vent, and the piece was primed ; fo that no part 
of the powder of the charge was loft in the aft of loading, as 
is always the cafe when the powder is put loofe into the barrel t 
nor was any part of it expended in priming ; but the whole 
quantity was fafely lodged in the bottom of the bore or cham- 
ber of the piece, and the bullet was put down immediately 
upon it, without any wadding either between the cartridge 
and the bullet, or over the bullet. 
The bullets were all caff in the fame mould, and confe- 
quently could not vary in their weights above two or three 
grains at moff, efpecially as I took care to bring the mould to a. 
proper temperature as to heat before I began calling ; and when 
Jeather was put about them, or other bullets than thofe of lead 
were made ufe of, the weight was determined very exactly before 
they were put into the piece. 
The diameter of the bullet was determined by measurement 
and alfo by computation from its weight, and the fpecific gra- 
vity of the metal of which k was formed ;; and. both thefe 
methods gave the fame dimenfions very nearly.. 
The apparatus was put up for making the experiments in a 
coach-honfe* which was found very convenient for the purpofe^ 
q " as 
