Dearborn’s gold standard Balance. AD 
Since writing the preceding remarks; an argument in fayor of the 
common swan-neck beam has. induced me to add some observations 
on that instrument. A hook, ‘suspended on the internal edge of a 
circle, must touch one point only at the bottom of the circle, or must 
touch more. If it touch but one point, it has not sufficient bearing for 
retaining the sharp edge of the circle and the roundness of the hook, 
suspended « on it. If it touch more points than one, its be 
be distributed on the bottom of the circle and on parts, which are 
higher than te bottom, An this case the shatp edge of the. cir- 
cle scrapes the sides or che bation of the Wikies 
extent of the angle, made is either. 08 of the oh be pipe 8S 
motion. The Conaernieace, ‘which alin will be Bigs seen, on 
examining beams of this construction, after being long i in use; either 
the sharp edge of the circle is worn down, or a notch is cut in the 
hook, embracing the edge of the circle, and preventing the freedom 
of ponies ane Meceine not ancommen to find beams in daily, 
a be sufficient for a beam, oety constructed = kept - 
order. 
Ifa description of an improved Hydrostatic Balance of simple 
construction, for gold and silver coins, would be acceptable to 
the Academy of Arts and Sciences, it shall be  Peeeey ina fu. 
ture communication. * 
* The original communication, dated Boston; August 10, 1801, has beéa 
tevised by the Author, a 
Balance are described in the explanation, and represented in the plate. _ te 
, 7 “ et ae a eee 
Mo. Bot. Garden, 
1897 
