upoirGnn- powder > &c. 2 35 
The pendulum N° 2. was furnifhed with two targets, which 
were circular pieces of very tough oak-plank, near five inches 
thick, placed on oppofite fides 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 la fled from experiment ISP9. to experiment when it 
was fo much fluttered as to be rendered unfit for further fervice*. 
The pendulum N° 3. was like the pendulum N° 2. ; only, 
indead 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 fhattered 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 direftion of its fibres. Thefe cylinders are 
13 inches in diameter, and about 5I 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 finifhed. It is dill in being, and appears to be very little 
the worfe for the fervice it has undergone. 
Fig. 7. fhews the two ends of the pendulum upon a large 
fcale, together with the hooks or grooves by which it was 
fufpended. 
tf, b , is the bar of the pendulum, which is feen broken ofi^ 
as there is not room to fhew the whole of its length* 
c , d \ are the pivots by which it was fufpended* 
f, is 
