MENTS IN APPARATUS FOR ASCERTAINING THE DENSITY OF VARIOUS BODIES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Edward Jones at the Office of the
Commissioners of Patents on the 7th October 1881.
EDWARD JONES, trading under the style or Firm of Dring & Fage, of Tooley
Street, in the Borough of Southwark, Scientific Instrument Makers. "IMPROVE
MENTS IN APPARATUS FOR ASCERTAINING THE DENSITY OF VARIOUS BODIES."
This Invention is intended to apply more particularly to means for ascertaining
the specific gravity of the saccharine solutions used by brewers, and on which a
duty has to be paid, but it is equally applicable to measuring the specific gravity of
other fluids, the density of which may range between that of pure alcohol (*792)
and mercury (13-6).
The apparatus consists of a pillar or standard carrying at its upper end the
bearings to receive the knife edge pivots of a beam. One arm of this beam is
shorter than the other, and from the shorter arm is hung a vessel of a given
capacity to contain the saccharine solution or other fluid to be tested. The longer
arm is marked off with a scale denoting degrees of specific gravity, and, if desired,
lbs. per gallon, or any other scale, and it is provided with a sliding weight.
This scale, when the instrument is to be used as a saccharometer, is preferably
calculated from the standard of water at a given temperature.
Secured to the side of the pillar, and in the same line with the shorter arm of
the beam, is a bracket which supports a guide in which the armn works. The object
of this guide is to hold the bean steady while the weight is being shifted and the
vessel containing the solution is being placed in position, by which means the knife
edges are less likely to become worn.
Secured to the side of the short arm and parallel with it is a pointer, which in
combination with a small scale secured to the side of the guide denotes when the
beam is in equilibrium. The scale may also be marked off with tenths of a degree,
so that so many of such parts of a degree may be read off after the number of
degrees has been fixed by the sliding weight. This arrangement is however suitable
only for rough readings.
For more careful readings instead of the scale on the guide I prefer to mark off
one side of the scale on the beam for degrees and the other side for tenths, and to
use two weights on the same beam, but on opposite sides thereof, one to denote the
D

page_text: degrees and a smaller one to denote the tenths. By this arrangement the finest
readings may be obtained with great speed and facility.
On the opposite of the pillar, and pendent from a bracket piece secured to
the head thereof, is a plumb bob, by means of which the verticality of the pillar
may be ensured before the measuring commences.
When the instrument is to be used as a saccharometer it will be sufficient that
the scale shall read from 1000° to 1500°, any numbers over 1500 being obtained by
replacing the weight with a heavier one, or by using another instrument set for a
higher reading.
The divisions of the scale will however be made according to the particular use
for which the instrument is intended.
It will be evident that the specific gravity of solid bodies may also be obtained
by the use of the instrument above described.