AN IMPROVED BALANCE POR ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS, ALSO APPLICABLE FOR OTHER PURPOSES
Year: 1869

page_text: LETTERS PATENT to Alphonse Bodart, of Huye, in the Kingdom of
Belgium, Manufacturer, for the Invention of "AN IMPROVED BALANCE
POR ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS, ALSO APPLICABLE FOR
OTHER PURPOSES."
Sealed the 22nd December 1869, and dated the 2nd October 1869.
COMPLETE SPECIFICATION filed by the said Alphonse Bodart at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 2nd October 1869, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALPHONSH
BODART, of Huye, in the Kingdom of Belgium, Manufacturer, send
greeting.
WHEREAS I am in possession of an Invention for "AN IMPROVED
BALANCE FOR ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS, ALSO APPLICABLE
FOR OTHER PURPOSES," and have petitioned Her Majesty to grant unto me,
my executors, administrators, and assigns, Her Royal Letters Patent for
the same, and have made solemn Declaration that I verily believe myself
to be the first and true Inventor thereof.

page_text: NOW KNOW YE, that I, the said Alphonse Bodart, do hereby declare
that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of my said Invention, and
the manner in which the same is to be performed, reference being had
to the Drawing hereto annexed and forming part of this Specification,
and to the figures and letters marked thereon, that is to say :—
The Invention consists in the construction of an improved balance for
ascertaining the specific gravity or density of liquids by means of a
plunging body of an exactly determined volume suspended to the beam
of a peculiarly constructed balance, the same being applicable to solid
bodies and for weighing precious metals and other articles of small
volume. This improved balance differs in its construction and in its
mode of operating from the hydrostatic balance; this latter requires
several operations and calculations for. ascertaining the specific gravity
of liquids, whilst with this balance a single operation is only necessary
without any calculation.
The Drawing hereto annexed, which is drawn to half the full size,
shows the balance with its accessories, Figure 1 being a front elevation
of the improved balance, and Figure 2 side elevation of the same.
It is composed of a foot A having at its upper part a ring B, on which
is soldered a frame C. On this ring is fixed a distended wire, which
carries a balance or scale beam E furnished with a long needle or
hand g. At each end of the beam a plate or scale F, F, is also
suspended by means of a wire. On one of the scales F' are placed
weights D, underneath the other scale is attached a body G, which I
call a plunger, and which is of a determined volume as herein-after
described, and which is plunged into the liquid the specific gravity of
which is to be ascertained. A cross piece H prevents the scales from too
great oscillation, and is fixed to the middle of the foot of the balance.
The plunger may be of blown glass and is ballasted with sand or other
material, and is made exactly of the volume required, videlicet, one
hundred cubic centimeters, which is equal to one decalitre, the
correctness of which is ascertained by its losing when plunged into
distilled water at four degrees Centigrade of temperature exactly one
hundred grammes of its weight. A. wire passing through a stopper
serves to suspend the plunger. When required to ascertain the specific
gravity of acids the stopper must be made of india-rubber, and the
suspension wire of platinum. As the plunger should be entirely

page_text: immersed in the liquid to be tested it should be heavier than an equal
volume of the liquid. This weight may be regulated with ballast. In
using the improved balance for liquids it is first placed in equilibrium,
the plunger is placed on one side in a vessel or recipient, the weights
on the other side; afterwards I pour into the vessel or recipient the
liquid the specific gravity of which is to be ascertained, and take off
weights until the equilibrium of the balance is restored. The weights
removed indicate exactly the specific gravity of the liquid; for example,
if it is desired to ascertain the specific gravity of milk, if it is pure it
will be necessary to take off one hundred and three grammes weight to
restore the equilibrium of the balance, the specific gravity is therefore
one hundred and three, water being calculated at one hundred. The
following is another method of checking the first:-I proceed at first
as above described, but instead of taking off weights from the scale F¹,
I place weights on the scale F above the plunger until the equilibrium
of the balance is restored. The weights thus added indicate the specific
gravity of the liquid. The specific gravity of liquids diminishes with
the increase of temperature. It is therefore necessary to make
allowance for the temperature of the liquid when making experiments
which require a certain precision. It is known that the specific gravity
of solids is ascertained by dividing their weight by their volume, for
example, if a body weigh eighteen drammes and its volume be nine
cubic centimêtres its specific gravity will be two. In cases where
the exact volume of solids is difficult of ascertaining the improved
balance may be employed in the following manner :-I take off the
plunger, replace it by threads in which is placed the solid, which
is left suspended in a vessel, I then equilibrate the balance with weights;
these arrangements being made I pour distilled water into the vessel at
four degrees Centigrade until the solid is entirely covered, and at at the
same time I remove weights to equilibrate the balance. The weights
removed indicate exactly the volume of the solid, one gramme corre-
sponding to one cubic centimetre. This method is not new, and is only
stated in order to shew that the improved balance can be used for this
kind of test. Experience has proved that this balance is highly sensitive.
and may be employed as an ordinary balance or scale for weighing with
precision precious metals and stones and other articles of small volume.
It is often necessary to ascertain the weight of corn and other substances
for better determining their quality, corn for instance being much better
the heavier it weighs. The balance gives with promptitude the

page_text: indications sought for, it being merely necessary to measure and weigh
one décalitre of the grain, and according to its weight in grammes so
will be the weight in kilogrammes per hectolitre.
The plunger herein-before described may also be applied to the beam
of an ordinary balance for ascertaining the specific gravity of liquids.
Having now described the nature of my Invention, and the manner of
performing the same, what I claim as new is,―
Firstly. The arrangement or construction of a balance for ascertaining
the specific gravity of liquids, also applicable to other purposes, sub-
stantially as herein-before described and represented in the accompanying 1
Drawing.
Secondly. The construction and employment of the plunger in com-
bination with balance mechanism, substantially in the manner and for
the purposes herein-before described.
In witness whereof, I, the said Alphonse Bodart, have hereto 1
set my hand and seal, this Twenty-eighth day of September, in
the year of our Lord One thousand eight hundred and sixty-
nine.