[ 142 3 
N. B. The weight of the fcale and pulley was 3 oz.; 
and that 1 oz. fufpended upon one of the radii, at 
12 i iches from the center of the axis, juft over- 
came the fricftion fcale and load of 7 \ lb. ; and 
placed at 14 inches, overcame the fame reftft- 
ances with 9 lb. in the fcale. 
Reduction of the preceding Specimen. 
N°. 5. being taken for the maximum, the weight 
in the fcale was 7 lb. 8oz. which, with the weight of 
the fcale and pulley 3 oz. makes 7 lb. 1 1 oz. equal to 
1 23 oz.; this added to the fri&ion of the machinery, 
the fum is the whole reftftance *. The fri&ion of 
the machinery is thus deduced : Since 20 turns of 
the fails raifed the weight 1 1,3 inches, with a double 
line, the radius of the cylinder will be .18 of an 
inch ; but had the weight been raifed by a fingle 
line, the radius of the cylinder being half the former, 
viz. .09, the reftftance would have been the fame : 
we ftiall therefore have this analogy; as half the 
radius of the cylinder, is to the length of the 
arm where the fmall weight was applied ; fo is the 
weight applied to the arm, to a fourth weight, which 
is equivalent to the fum of the whole reftftance to- 
gether; that is, .09 : 12,5 : : 1 oz. : 1390Z.: this 
exceeds 1 2 3 oz. the weight in the fcale, by 1 6 oz. or 
1 lb. which is equivalent to the fri&ion ; and which, 
added to the above weight of 7 lb. 1 1 oz. makes 
8 lb. 11 oz. = 8,69 lb. for the fum of the whole re- 
* The reftftance of the air is not taken into the account of 
reftftance, bccaufe It is infeparable from the application of the 
power. 
8 ftftance ; 
