Experiments upon Gunpowder, 7 



it was fixed ; but this target, being too thin, was very- 

 soon ruined. 



The pendulum No. 1 was furnished with two targets, 

 which were circular pieces of very tough oak-plank, near 

 five inches thick, placed on opposite sides of the plate 

 of the pendulum, and firmly fixed to it by screws, and 

 to each other by iron straps. When one of these targets 

 was ruined the pendulum was turned about and the 

 other was made use of. This pendulum lasted from 

 experiment No. 9 to experiment No. 39, when it 

 was so much shattered as to be rendered unfit for 

 further service.. 



The pendulum No. 3 was like No. 1 ; only, instead 

 of oak, elm-plank, near seven inches in thickness, was 

 made use of for the targets. This pendulum served 

 from experiment No. 40 to experiment No. loi, in- 

 clusively. 



But finding that targets made of planks of the tough- 

 est wood were very soon shattered to pieces by the 

 bullets, I composed the pendulum No. 4 in a different 

 manner. Instead of circular pieces of plank, solid 

 cylinders of elm-timber were made use of for the tar- 

 gets, so that the bullets now entered the wood in the 

 direction of its fibres. These cylinders are 13 inches 

 in diameter, and about Cj\ inches in length, hooped 

 with iron at both their ends, to prevent their splitting, 

 and they are firmly fastened to the plate of the pendu- 

 lum and to each other by four iron straps. This pen- 

 dulum lasted till the experiments were finished. It is 

 still in being, and appears to be very little the worse for 

 the service it has undergone. 



Fig. 7 shows the two ends of the pendulum upon a 

 large scale, together with the hooks by which it was 

 suspended. 



