Mr. s me a ton on Mechanic Power. 
459 
it is fenfibly compounded with another law, viz. the 
x »« 
law of acceleration by gravity. 
DESCRIPTION OF THE MACHINE. 
ab is the bafe of the machine placed upon a table. 
ac is a pillar or ftandard. 
cd is an arm, upon the extremity of which is fixed a 
plate fg, which is here feen edge-ways, through which is a 
fmall hole for receiving a fmall fteel pivot e, fixed in the 
top of the upright axis e b; the lower end of this axis 
finifhes in a conical fteel point, which refts upon a fmall 
cup of hard fteel polifhed at b. 
hi is a cylinder of white fir, which paftes through a 
perforation in the axis, and therein fixes ; and, upon the 
two arms formed thereby, are capable of Hiding 
kl two cylindric weights of lead of equal fize, which 
are capable of being fixed upon any part of the cylindric 
arms, from the axis to their extremities, by means of two 
thin wedges of wood. The two weights, therefore, being 
at equal diftances from the center, and the axis perpen- 
dicular, the whole will be balanced upon the point at b, 
and moveable thereupon by an impelling power, with 
very little fridlion. 
Upon the upper part of the axis are formed mn, two 
cylindrical barrels, whereof m is double the diameter 
of n ; they have a little pin ftuck into one fide of each 
at o, p . 
Q_is a piece capable of Hiding higher or lower, as occa- 
Hon requires ; and carries 
Vol. LXVU P p p r a 
p p p 
