Improvements in INSTRU- MENTS, COMMONLY CALLED HYDROMETERS, FOR TESTING THE SPECIFIC GRAVITY OF LIQUIDS
Year: 1875

page_text: LETTERS PATENT to James Joseph Пlicks, of Hatton Garden, in the
County of Middlesex, for the Invention of "Improvements in INSTRU-
MENTS, COMMONLY CALLED HYDROMETERS, FOR TESTING THE SPECIFIC GRAVITY
OF LIQUIDS."
PROVISIONAL SPECIFICATION left by the said James Joseph Hicks
at the Office of the Commissioners of Patents, with his Petition,
on the 30th July 1875.
I, JAMES JOSEPH ПICKS, of Hatton Garden, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN INSTRUMENTS, COMMONLY CALLED HYDROMETERS, FOR TESTING
THE SPECIFIC GRAVITY OF LIQUIDS," to be as follows
Heretofore hydrometers made of glass have had their stems made
of plain or clear glass, which, according to one plan, had the scales or
graduations engraved on the outer surface thereof. This method however
had the disadvantage that after a short time the scales or graduations

page_text: became indistinct, on account of the coloring matter becoming removed
or washed out therefrom by contact with the liquid being tested or
otherwisc.
According to other plans the stems were, as before described, made of
plain or clear glass, whilst the scales or graduations were made upon a
paper, ivory, or other scale fixed in the interior thereof. By these modes
however difficulty was experienced in reading the indications on account
of the refraction produced by the light passing through the thickness of
the glass and through the water.
By the first part of my Invention I obviate these difficulties by
forming the stem either partially or entirely of enamel, opal, or other
like glass, and engraving the scale or graduations on the outer surface
of the enamel, opal, or other like glass stem or part of stem; or I form
the stem of plain or clear glass,' and engrave or othci wise mark the scale
or graduations on the outer surface thereof, as heretofore, but in order
to render the scale or graduations readily visible I place in the interior
of the stem a tube or strip of paper or other material to reflect the light
therethrough.
The Invention relates, secondly, to hydrometers for testing salt water
or other liquids in which an open scale is desirable. In carrying this
part of my Invention into effect I engrave the stem with a scale or gra-
duations, say from 0 to 10, or from 0 to 20. In the former casc, in
order to read to 40 grains of specific gravity, I use three equal weights
placed at the upper end of the stem, thus when it is desired to read
from 10 to 20, a single weight is placed at the upper part of the stem,
when from 20 to 30, two weights are so placed; and from 30 to 40,.
three of such weights are required. When in the length of the stom
the scalc or graduations indicate, say, 20 grains, I engrave, as heretofore,
the stem on two sides, the one side indicating, say, from 0 to 20, and
the other, say, from 20 to 40, in which case in reading from 0 to 20, no
extra weight is employed, whilst in reading from 20 to 40 only one extra
weight is required, such weight being placed at the upper end of the
stem, as in the previous arrangement.
By these means, on account of the weights not being immersed in the
liquid being tested, I am enabled to dispense with the table of cor-
rections required in Sykes's and other similar hydrometers, whilst by

page_text: employing equal weights or only one weight I obviate to a great extent
the errois to which an inexperienced or careless operator is hable when
using a number of unequal weights.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Joseph Hicks in the Great Seal Patent
Office on the 28th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
JOSEPH ПICKS, of Hatton Garden, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of July, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Joseph Hicks, Her special
license that I, the said James Joseph Hicks, my executors, admini-
strators, and assigns, or such others as I, the said James Joseph
Hicks, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN INSTRUMENTS, COMMONLY CALLED HYDROMETERS, FOR
TESTING THE SPECIFIC GRAVITY OF LIQUIDS," on the condition (amongst
others) that I, the said James Joseph Hicks, my executors or admi-
nistrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the dato
of the said Letters Patent.
NOW KNOW YE, that] I, the said James Joseph Hicks, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the

page_text: Drawings hereunto annexed, and to the letters and figures marked
thereon, that isto say .
Heretofore hydrometers made of glass have had their stems made of
clear or translucent glass, which according to one plan had the scales
or graduations engraved on the outer surface thereof. This method
however had the disadvantage that after a short time the scales or
graduations became indistinct, on account of the colong matter
becoming removed or washed out therefrom by contact with the liquid
being tested or otherwise.
According to other plans the stems were, as before described, made of
clear or translucent glass, but the scales or graduations were made upon
a paper, ivory, or other scale fixed in the interior thereof By these
modes however difficulty was experienced in reading the indications, on
account of the refraction produced by the light passing through the
thickness of the glass and through the water
By the first part of my Invention I obviate the above-mentioned
difficulties. I form the stem either partially or entirely of enamel, opal,
⚫or other like semi-transparent or opaque glass, and engrave the scale or
graduations on the outer surface of the enamel, opal, or other like semi-
transparent or opaque glass stem or part of stem, and I preferably fill in
such engraving with glass enamel fused therein, or I dispense with the
engraving, and simply paint the scale or graduations thereon with glass
enamel, which is afterwards fused thereon In carrying this part of my
Invention into effect I prefer to make the stem of black or other daik
colored glass or glass enamel, and to mark the scale or graduations :
thereon in white or other light colored enamel, although, if desired, the
reverse may be used.
According to another plan I form the stem of clear or translucent
glass, and engrave or otherwise mark the scale or graduations on thic
outer surface thereof, as heretofore, but in order to render the scale or
graduations readily visible I place in the interior of the stem a tube or
strip of paper or other material of any desued or suitable color to
render the scale or graduations more readily visible.
The second part of my Invention, which is represented at Figures 1
and 2 of the accompanying Drawings, relates to hydrometers for testing 3
salt water or other liquids in which an open scale is desirable. In

page_text: carrying this part of my Invention into effect I engrave or otherwise
mark the stem b with a scale or graduations, say, for example, from 0 to
10, as shown at Figure 1; and in order to read to 40 grains of specific
gravity I use three equal weights a at the upper end of the stem, as
shown by dotted lines in Figure 1, a plan and edge view of one of such
weights being shown at Figures 2, thus when it is desired to read from
10 to 20, a single weight a is placed at the upper part of the stem 6;
when from 20 to 30, two weights a are so placed, and from 30 to 40,
three of such weights are required
By these means, on account of the weights not being immersed in
the liquid being tested, I am enabled to dispense with the table of cor-
rections required in "Sykes'," and other similar hydrometers, whilst by
employing equal weights I obviate to a great extent the errors to which
an inexperienced or careless operator is liable when using a number of
unequal weights
I would here remark that since filing my Provisional Specification I
have been advised that it is doubtful whether I could sustain a claim for
the open scale hydrometer therein described as reading from 0 to 20
without any moveable weight added thereto, and from 20 to 40 by the
employment of only one additional weight, and for this reason I desire
to disclaim and I do licreby disclaim such arıangement
Having thus described the nature of my said Invention, and the mode
in which I carry the same into effect, I would have it understood that
what I claim is,—
Firstly. Forming the stems of glass hydrometers cither partially or
entirely of enamel, opal, or other like opaque or semi-transparent glass,
upon which the scales or graduations are engraved or otherwise indicated
on the outer surface thereof, in manner and for the purpose substantially
as herein described.
Secondly I claim, when forming the stems of hydrometers of clear or
translucent glass with the scale or graduations on the exterior thereof,
placing in the interior thereof a tube or strip of paper or other material
of any desired or suitable color to render the scale or graduations more
readily visible.
And, Thirdly. I claim, when employing hydrometers with stems having
open scales marked thereon, say, for example, from 0 to 10, using thicc

page_text: equal weights to indicate up to 20, 30, or 40 grams of specific gravity,
as may be required, in manner and for the purpose substantially as
herein shown and described.
In witness whereof, I, the said James Joseph Ilicks, have here-
unto set my hand and seal, this Twenty-sixth day of January, a
in the year of our Lord One thousand eight hundred and seventy-
SIX.