48 Dearborn’s gold standard Balance. 
derate, and remain down. When the motor is too low, the oscilla- 
tions of the beam are quickened, and it does not turn with the ease, 
of which it is susceptible. The beneficial effects of the motor arise 
from this cause. While the centre of gravity is below the centre of 
motion, it tends to draw the beam to a level position. ‘The flexion 
of the beam, by the power of the weights, has the same tendency, 
as exemplified in Fig. 3. Hence éwo obstacles are to be surmounted, 
whenever a beam is charged with weights sufficient to spring it 
downward. Ifthe motor be raised, it raises the centre of gravity 
above the centre of motion, and one of those two obstacles is not 
only removed thereby, but is brought into a position to counteract 
the other obstacle. A standard is fixed under each arm of the beam 
to support it when at rest, and it should be let down upon those 
supports, whenever the place of the motor is to be changed, or the 
scales to be loaded or discharged. <A balance of this construction 
turns with the ease, necessary for weighing the smallest pieces of coin 
singly, and is almost equally susceptible when charged with six 
thousand pennyweights in each scale. 
A Gold Standard Balance of the foregoing description is distin- 
guished as the higher style. The same principles have been applied 
in the construction of another of equal size and accuracy, but less 
expensive; this is denominated the /ower style, as it is inferior in 
elegance and convenience. Another of the higher style has been made 
upon a reduced scale for weighing gold, not exceeding the amount of 
one thousand dollars at a draft. | 
A Silver Standard Balance hasalso been made, for ascertaining the 
exact number of dollars in any parcel, from five to one thousand. 
This, if deserving the notice of the Academy, may form the subject 
of a future communication. 
