[ i 4 o ] 
H is a barrel upon the upright axis, whereon is 
wound a cord j which, being drawn by the 
hand, gives a circular motion to the axis, and 
to the arm F G ; and thereby carries the axis 
of the fails in the circumference of a circle, 
whofe radius is D I, caufing thereby the fails 
to ftrike the air, and turn round upon their 
own axis. 
At L is fixed the end of a fmall line, which palling 
through the pullies M N O, terminates upon a 
fmall cylinder or barrel upon the axis of the 
fails, and, by winding thereon, raifes 
P the fcale, wherein the weights are placed for 
trying the power of the fails. This fcale, moving- 
up and down in the direction of the upright 
axis, receives no diflurbance from the circular 
motion. 
Q^R two parallel pillars Handing upon the arm F G, 
for the purpofe of fupporting and keeping 
Heady the fcale P ; which is kept from fwing- 
ing by means of 
S T two fmall chains, which hang loofely round the 
two pillars. 
W is a weight, for bringing the center of gravity of 
the moveable part of the machine into the cen- 
ter of motion of the axis D E. 
V X is a pendulum, compofed of two balls of lead, 
which are moveable upon a wooden rod, and 
thereby can be fo adjuHed, as to vibrate in any 
time required. This pendulum hangs upon a 
cylindrical wire, whereon it vibrates, as on a 
rolling axis. 
Y is a perforated table for fupporting the axis of 
the pendulum. 
Note> 
