Improvements in Instruments used for Determining the Specific Gravities of Liquids.
Year: 1891

page_text: Date of Application, 21st July, 1891
Complete Specification Left, 2nd Feb., 1892-Accepted, 19th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements in Instruments used for Determining the Specific
Gravities of Liquids.
I, FREDERICK WILLIAM FLETCHER of Beauchamp Lodge, Enfield, in the
County of Middlesex, Manufacturing Chemist, do hereby declare the nature of
this invention to be as follows:-
My invention relates to improvements in instruments known as hydrometers,
used for the purpose of determining the specific gravities of liquids, and its object
is to provide the hydrometer with a thermometer arranged in such a way that the
temperature of the liquid under examination can be ascertained at the moment of
taking its specific gravity.
It is well known that it is essential to take the specific gravity of a liquid at a
certain standard temperature, and, hitherto it has been customary either to employ
a separate thermometer for this purpose, or to use a hydrometer with a thermo-
meter enclosed therein. The objection to the first mentioned method is obvious,
and the second method is defective, inasmuch, as amongst other objections, the
bulb of the thermometer does not come into direct contact with the liquid, and
hence some time must clapse before a correct reading can be obtained.
By my invention the hereinbefore described objections are overcome.
In my improved arrangement, the ordinary bulb of the hydrometer is replaced
by the bulb of a thermometer, the stem of which passes through the body of the
hydrometer into its stem. Attached to the bulb of the thermometer and below it,
is the hydrometer bulb, which may be of any convenient shape or size.
A double scale of paper, ivory, or any other suitable substance being attached to
the stem of the instrument, an accurate hydrometric and thermometric reading can
be simultaneously obtained.
Dated this 20th day of July 1891
COMPLETE SPECIFICATION.
Improvements in Instruments used for Determining the Specific
Gravities of Liquids.
1, FREDERICK WILLIAM FLETCHER, of Beauchamp Lodge, Enfield, in the
County of Middlesex, Manufacturing Chemist, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention relates to improvements in instruments known as hydrometers, used
for the purpose of determining the specific gravities of liquids, and its object is to
provide the hydrometer with a thermometer arranged in such a way that the
temperature of the liquid under examination can be ascertained at the moment of
taking its specific gravity. Hitherto it has been customary either to employ &
separate thermometer or to use a hydrometer with a thermometer enclosed therein.
The objections to the first mentioned method are sufficiently obvious, and the
second method is defective, amongst others for the two following reasons. First,
the bulb of the thermometer does not come into direct contact with the liquid
under examination, and hence some time must elapse before the exact temperature
can be ascertained; and, in the second place, the thermometer scale being in the
body of the hydrometer, and hence wholly immersed in the liquid, it is not
..מ
B

page_text: possible, if the liquid be opaque, to read the temperature without disturbing the
instrument.
In my improved instrument, or thermo-hydrometer, these objections are over-
come.
In the accompanying drawings,
Fig. I is a front view of the instrument showing hydrometer scale, and Fig. II is
a back view of the instrument showing thermometer scale.
It is not, however, necessary that the two scales should be arranged in this
manner. They may, for example, be placed side by side, or in any other desired
position, either upon or within the stem of the instrument.
I prefer to construct my improved instrument entirely of glass, but portions of it,
may, if desired, be constructed of metal, or any other suitable material.
In both Figs. I and II, A is the bulb of the thermometer, and B the bulb of the
hydrometer. The stem C of the thermometer passes through the body D and into
the stem E of the hydrometer, wherein or whereon a double scale, as above
described, made of paper, ivory, glass, or other suitable material will indicate at
the same moment both the specific gravity and temperature of a liquid in which the
instrument is immersed.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed. I declare that what I
claim is :-
1. The combination with a hydrometer of a thermometer, the bulb of which is 80
arranged that it comes into direct contact with the liquid in which the instrument
is immersed thus insuring the utmost sensibility.
"
2. The prolongation of the stem of the thermometer into the stem of the hydrometer
in or upon which is arranged a double scale, so that both the temperature and the
specific gravity of the liquid can be ascertained, without employing a separate
instrument or removing the hydrometer from the liquid.
· Dated this 1st day of February 1892.