upon Gun-powder^ &c. 23.5: 
The pendulum N° 2. was fumifiied with two targets, which 
were circular pieces of very tough oak-plank, near five inches 
thick, placed on oppofite Tides of the plate of the pendulum, 
and firmly fixed to it by fcrews, and to each other by iron 
draps. When one of thefe targets was ruined, the pendulum 
was turned about,, and the other was made ufe of. This pen- 
dulum laded from experiment N°p. to experiment N°3p. when it 
w r as fo much (battered as to be rendered unfit for further fervice., 
The pendulum N° 3. was like the pendulum N° 2. ; only,. 
Indeed of oak, elm-plank near feven inches in thicknefs was- 
made ufe of for the targets. This pendulum ferved from ex- 
periment N° 40. to experiment N° 1 o 1 .. inclufively. 
But finding that targets made of planks of the toughed 
wood were very foon (battered to pieces by the bullets, I com- 
pofed the pendulum N° 4. in a different manner. Indead of 
circular pieces of plank, folid cylinders of elm-timber were 
made ufe of for the targets, fo- that the bullets now entered 
the wood in the direction of its fibres.. Thefe cylinders are 
13 inches in diameter, and about 54 inches in length, hooped 
with iron at both their ends to prevent their fplitting, and 
firmly fadened to the plate of the pendulum, and to each other 
by four iron draps. This pendulum laded till the experiments 
were finiihed. It is dill in being, and appears to be very little 
the worfe for the fervice it has undergone. 
Fig. 7. (hews the two ends of the pendulum upon a large 
fcale, together with the hooks or grooves by which it was 
fufpended. 
a, b , is the bar of the pendulum, which is feen broken off*, 
as there is not room to (hew the whole of its length. 
c 9 d y are the pivots by which it was fufpended. 
