46 Dearborn’s gold standard Balance. 
The principal peculiarity of the beam, consists in the manner of 
forming and finishing the ends for suspending the scales. It resem- 
bles the common swan-neck beam reversed; the extremities, which 
are of steel, are wrought to a sharp edge, turning upward, exactly on 
a line with the edge of the axis or centre of motion, and equidistant 
from it. | To obtain exact equality in the distances the ends, after 
being tempered, are made sharp by rubbing with an oil-stone, where- 
by the length of either arm can be increased or diminished in the 
smallest quantity required. For attaching scales to the beam, two 
implements, termed pendants, are suspended on these sharp edges ; 
they are thus formed. Between two parallel brass plates, about three 
inches long, are inserted, at the upper end a steel cap, well tempered 
and polished, and at the lower end, an iron plate, with a hole in the 
centre. Through | this hole an eye-bolt is passed upward, and a 
double nut is screwed on above the plate. By this construction the 
suspension of the scales is so adjusted, that when let down, both will 
rest on the table at the same instant, if the beam be level.’ The 
pendants thus constructed, produce the least possible friction, as 
thieir sides can touch the beam in no part, except a single point at 
each extremity of the sharp edges which are much longer than 
the thickness of the beam. Over the centre of the beam a small 
weight, in the form of an antique vase, turns on an axis to- 
ward. the right or left, and is adjusted by two screws; this is termed 
an Equipoise, its design being to level the beam, when cither end 
a have obtained a preponderance from unequal wearing of the 
, Magnetic attraction* or other causes, some of which may 
* Having noticed beams, which in time had lost their original equilibrium, 
the eircumstance led to an inquiry into the causes of such variation, and suspect- 
ing that one of them might be found in magnetic attraction, I sought conviction in 
experiment. Upon approaching the north point of a magnetic needle with one 
