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The angle of the beam ACB Is i68° the 
radius C A or C B, 6 inches ; the breadth of the 
beam in the middle ^ of an inch, at the ends ^ ; 
the thicknefs at the end B where it is flit 4.; every 
where elfe The length of the arbor i,^. j dia- 
meter of the pivets The weight of the coun- 
terpoife one ounce avoirdupoife. 
The hook, with the loop and fleel pin included, 
0,68 avoirdupoife. The diviflon of 50 is at the top 
of the ring. 
In making the beam, the point of the index E 
mufl: be equally diflant from the centers A and B ; 
the whole beam and index made fo as to poife itfelf, 
and remain at reft in any pofltion, before the coun- 
terpoife fleel pin and loop are put on. 
The counterpoife being at firil made too heavy, to 
adjufl; it, take off the beam, but let the two cocks 
and ring remain ferewed on j hang then a fine wire 
and plummet on the top diviflon, and with a watch 
glafs look through one pivot hole till you fee the 
wire againfl the other j turn the ferew G till the 
wire bifeds the hole, and the top diviflon is then 
perpendicularly over it. Take away the plumb line 
and put on the beam and counterpoife j on the loop 
hang a weight, which together with the fleel pin 
•and loop makes one ounce avoirdupoife j turn now, 
by degrees, feme metal off the counterpoife, till the 
index points at the top diviflon, and the counterpoife 
will be truly adjufted, whether the arms of the beam, 
C A, C B, are precifely equal or not : for though 
the arms . fhould be nearly equal, it is not neceflary 
they fhould be exadly fo, as in fcales. 
The 
