[ IZ2 ] 
refifiing bodies in the dire&ions K E, and L F . This 
force therefore being to the force exprefied by G E, 
as the fine of the angle (E G O, or) E K G, to the 
radius, and the Force G E being (as was faid before) 
to the power P, as the radius to the fine of half the 
vertical angle of the wedge; it follows, that the force 
with which the refilling bodies are protruded in the 
directions K E, and L F, is to the power P , as the fine 
of the angle E K G, or F L H, which thefe direc- 
tions make with the fides of the wedge, to the fine of 
half the vertical angle of the wedge: and confequently, 
if the refilling forces, which at on the wedge accord- 
ing to thefe diretions, are to the power P in this pro- 
portion, there will be an aequilibrium between them. 
Hence we may obferve, that, if from D (the mid- 
dle point in the back of the wedge) a line be drawn, 
as D A, meeting one of the fides ; the refilling forces, 
which mull recede in diretions parallel to D A; will 
be to the power which fullains them, as D B, the 
height of the wedge, to the line D A ; and this power, 
if at all increafed, will remove thefe refilling bodies. 
When therefore the retifVing bodies mull recede in 
lines parallel to the back of the wedge, their refin- 
ance will be to the power which fullains it, as the 
height of the wedge, to half the breadth of it’s back. 
This proportion of the power to the refinance in this 
lart mentioned cafe, is confirmed by an experiment ufed 
by Gravefande and others, to Ihew the nature of the 
wedge. For, in this experiment, a wedge is drawn 
down between two cylinders, which roll on rulers par- 
allel to the back of the wedge, and are kept together 
by weights. And probably it was from their attend- 
ing to this experiment, without conlidering other cafes. 
4 
