[ 66 ] 
and not thick) 9 Ounces, 19 Dwt, 4 Grains 5 the Fric- 
tion 3 Dwt, 11 Grains and an half; but with the 
proper Correction, which I (hall explain hereafter, it 
muft Be only 9 Ounces, 17 Dwt, iy Grains; the 
Fridion 7 Dwt, 7 Grains. Here the Foot of the Prop 
is to be 26 Inches from the Centre. 
Experiment III. 
If the End of the Prop is placed under a Point in 
the Bar, fo that the Horizontal Diftance of the Foot 
of the Prop be exadly equal to the Diftance of the 
Centre of Gravity from the faid Centre of Motion, 
viz. 20, f Inches; the Power or Preffure fuftain'd by 
the Prop will be precifely equal to the W eight of the 
Bar, viz. 12 Ounces, 12 Dwt, 12 Grains. In this 
Cafe, the Prop is diftant from the Centre of Motion 
on the Bar 17,9 Inches, and the Fridion 4 Dwt, y 
Grains. 
The Third Case, 
In which the Angle made by the Trop with the 
horizontal Line is given, either acute or obtufe. 
As this Cafe is very intricate, (on Account of the 
feveral Powers of the Sine and Cofine of the given 
Angle, which are multiplied into the Prop and into 
the Weight of the Beam) we will exemplify it only 
in one Experiment ; which is, when the Angle made . 
by the Prop, with the horizontal Line contain'd be- 
tween the Foot of the|Prop and the Centre, is acute : 
then there is a Maximum of Preffure, which I will 
(hew by Experiment to be the very fame as the Cal- 
culation gives. I fuppofe the Angle made by the 
Prop and the horizontal Line to be 60 Degrees: The 
Cal- 
