( 229 ) 
In the prefent Experiment B E is an inclin’d Plane, 
on which the Roller C is to roll up, touching the faid 
Plane at the Point ^ ; A M is the Wheel behind that 
Plane, another fuch Plane, and equally inclin’d, being 
alfo fuppos’d, behind the Wheel, to fupport the other 
End of the Roller. 
The Lines of Diredion of the Power and Weight 
being a P and d W, through the Point of Gontad, 
or Center of Motion, c draws A D parallel to the Hori- 
zon, and perpendicular to ^ P and d W ; through the 
Center of the Engine, C draws a d Parallel to A D. 
Suppofe the Angle B A of the Plane’s Inclination to 
be 30®, the right Sine will then be equal to half the 
Radius ^ therefore dividing C ^ (the Radius of the 
Roller) into two equal Parts at if you draw k c 
and C r, the Angle k cQ will be equal to B A, and 
its Sine will be Ck. Now fince it is evidently the 
fame thing to make ufe oi a d for a Lever, whofe 
Center of Motion is at as of A D equal and paral- 
lel to it with its Center of Motion at r ; it follows 
that in this Inclination of the Plane, the Diftance of 
the Weight d k ls greater than d C (the Diftance of 
the Weight in the common Ufe of this Engine) by the 
Addition of the Quantity C the Sine of the Angle of 
Inclination and k the Diftance of the Power is lefs 
than C a (the Diftance of the Power in the common 
Way) by the Subtradion of the faid Qiiantity or Sine 
C k : confequently that on an inclin’d Plane ^ the Power 
is to the Weight : : as D ^ 7 : to A. Q, E. D. 
Corollary I. 
Hence it follows, that the Radius of the Wheel, 
and' the Radius of the Roller being given, the Lofs 
1 i ^ of 
