Usage/History: The analytical balance is the most
fundamental tool in the chemists arsenal. It is used to determine
the masses of, or in other words the amount of stuff in, objects
or samples. The balance is a comparison instrument. It compares
standard or known weights placed on the left-hand pan to unknown
samples or objects placed on the right-hand pan. The current
instrument also has a rider (a 10 mg bent wire weight which is
moved along the graduated scale on the top of the beam) to measure
small (1-10 mg) differences in mass. The glass case is to protect
the balance from drafts while samples are being weighed, as well
to keep the delicate mechanisms free from dirt.
According to MacNevin, Voland and Sons was established in
1888 in New Rochelle, N.Y.
Early descriptions of the balance and its use are provided
below:
Smith. "Weighing"
in ...QUANTITATIVE CHEMICAL ANALYSIS ... (1921)
Description: The balance has a 6 1/2" aluminum
beam graduated in white figures against a black strip on the
right side only in 10 mg by 0.2 mg with a 10 mg wire rider. The
balance has knife edges on planes for the beam and both pans.
The rider carrier is a simple hook on a brass rod sliding through
a brass tube attached through the wood case on the right side
of the balance. The beam is supported by a simple polished brass
column on a square brass base plate bolted to the slate base
of the balance. There is a white plastic scale attached to the
front of the brass base plate graduated in red and labeled: voland
& sons / (inc) / new rochelle,n.y. / patented. There is a
single bullseye level behind the column. The release mechanism
operates on the beam only (vertical lift type). The pans are
arrested through a second knob mounted below the heavy (3/4")
slate base, 16 5/8 x 9 1/2". The aluminum pans are supported
by nickel plated brass bows and double hook hangers. The balance
rests on a single rear post and two leveling screws operating
on solid brass rod protruding from either side of the front of
the slate base. The balance is enclosed in a glazed mahogany
case, 15 1/2w x 14 1/2h x 9 1/2", with a single sliding
door at the front. The case is stamped 21281 on the upper front
right corner, and there is an oval brass tag on the top front
right corner stamped: HUMBOLDT S-T-C / 2083.
The brass leveling feet have been stripped and refinished
with shellac, the brass base plate cleaned and refinished with
shellac, the remainder of the instrument and case merely cleaned
and waxed or oiled as appropriate.
References:
MacNevin, William Marshall, The Analytical Balance, Its Care
and Use, Handbook Publishers, Inc., Sandusky, Ohio, (1951), pg.
xi.
