IMPROVEMENTS IN HYDROSTATIC AND CERTAIN OTHER SCIENTIFIC INSTRUMENTS."
Year: 1872

page_text: LETTERS PATENT to Arthur Nicholls, of Barnsbury Road, Islington,
in the County of Middlesex, Scientific Instrument Manufacturer,
for the Invention of "IMPROVEMENTS IN HYDROSTATIC AND CERTAIN OTHER
SCIENTIFIC INSTRUMENTS."
PROVISIONAL SPECIFICATION left by the said Arthur Nicholls at
the Office of the Commissioners of Patents, with his Petition, on
the 23rd October 1872.
I, ARTHUR NICHOLLS, of Barnsbury Road, Islington, in the County
of Middlesex, Scientific Instrument Manufacturer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN HYDROSTATIC AND
CERTAIN OTHER SCIENTIFIC INSTRUMENTS," to be as follows:-
:-
Hitherto the graduations or numerical and linear or similar indications
on hydrostatic instruments, hydrometers, saccharometers, salinometers,
specific gravity instruments, alcoholometers, and certain other similar
scientific or philosophical instruments have been marked or engraved on
the metal pillar or stem of such instrument, hence they are not readily

page_text: perceptible or discernible and great difficulty is experienced in reading
off the graduations or indications, especially as instruments of these des-
criptions are frequently used in obscure places. Now my Invention has
for its object to remedy this evil, and it consists in fixing on or applying
to the metallic surface a surface of enamel or similar coating, layer, or
surface of some substance not easily affected by contact with liquids or
atmospheric air or other matter to which the instrument is likely to be
exposed, such substance forming a ground on which I mark graduations,
figures, lines, or other required indications, so that the same may be
readily visible or perceptible. The colour of the enamel or other ground
or surface should be different from that of the graduations, marks,
figures, lines, or indications. For instance, there may be black
graduations on a white enamelled ground, or vice versa.
In carrying out the Invention the enamel or other coating or applied
surface should not extend quite to the edges of the metal surface, stem,
or pillar, but the edges of the latter should extend a little beyond those
of the enamel-surface or coating so as to protect the same from injury.
Also the enamel surface or the marked or graduated coating may be.
sunk or countersunk in the metal pillar or stem so as to be further
protected. And this may be effected by forming a groove in the pillar or
stem, or by drawing it by gauge plates or otherwise so that without
weakening the metal it may duly protect the enamel or coating sunk
therein.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Nicholls in the Great Seal Patent Office 2
on the 23rd April 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
NICHOLLS, of Barnsbury Road, Islington, in the County of Middlesex,..
Scientific Instrument Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 3
Letters Patent, bearing date, the Twenty-third day of October, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Arthur Nicholls Her special license

page_text: that I, the said Arthur Nicholls, my executors, administrators, and
assigns, or such others as I, the said Arthur Nicholls, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter 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 Invention for "IMPROVEMENTS IN
HYDROSTATIC AND CERTAIN OTHER SCIENTIFIC INSTRUMENTS," upon the condition
(amongst others) that I, the said Arthur Nicholls, my executors or ad-
ministrators, 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 date
of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur Nicholls, 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 accompanying
Drawings, and to the letters and figures marked thereon, that is to say :-
Hitherto the graduations or numerical and linear or similar indications
on hydrostatic instruments, hydrometers, saccharometers, salinometers,
specific gravity instruments, alcoholometers, and certain other similar
scientific or philosophical instruments, that is to say, instruments for
ascertaining the density and specific gravity of fluids have been marked
or engraved on the metal stem or pillar of such instruments, and hence
they are not readily perceptible or discernible, and great difficulty is
experienced in reading off the graduations or indications, especially as
instruments of these descriptions are frequently used in obscure places.
Now my Invention has for its object to remedy this evil, and it consists
in fixing on or applying to the metallic stem a surface of enamel or similar
coating, layer, or surface of some substance not easily affected by
contact with liquids or atmospheric air or other matter to which the
instrument is likely to be exposed, such enamel coating, surface, or
substance forming a ground on which I mark graduations, figures, lines,
or other required indications, so that the same may be readily visible or
perceptible. The colour of the enamel or other applied ground or
surface should be different from that of the graduations, marks, figures,

page_text: lines, or indications; for instance,. there may be black graduations on a
white enamelled ground, and vice versa..
In carrying out the Invention the enamel or other coating or applied
surface should not extend quite to the edges of the metal surface, stem,
or pillar, but the edges of the stem or pillar should extend a little beyond
those of the enamel or other similar surface or coating so as to protect
the same from injury.
Also the marked or graduated enamel surface or coating may be sunk
or countersunk in the metal stem or pillar so as to be further protected,
and this may be effected by forming a groove in the stem, or
by drawing it by gauge plates or other means so that without
weakening the metal the metal may duly protect the enamel or coating
sunk therein.
The accompanying Drawings illustrate the mode in which my In-
vention is carried into effect.
Figure 1 is a front view of a saccharometer, to which my Invention is
applied; Figure 2 is a transverse vertical section of the same, but the
body of the instrument is in elevation; Figure 3 is a transverse horizontal
section of the stem.
A is the saccharometer or instrument, a its stem. A groove, or
vertical, or longitudinal recess is formed in this stem on both sides by
drawing the metal through gauge plates or by other ordinary means.
Into each groove thus produced a layer or surface of enamel is introduced
so as to fill or nearly fill the groove or recess, and the enamel is fused by
heat so that it becomes homogeneous and hard in the groove or recess; a*
is the enamel surface; 6 is an end plate fixed at the top of the grooved
stem; there is a similar end plate 6 fixed at the bottom thereof with a
screw shank to screw into the body of the saccharometer or instrument.
The required graduations, lines, figures and characters, or indications,
are painted, drawn, or marked on the enamel surface. a* in a colour
strongly contrasted with, or signally different from, the colour of the
enamel surface. Thus, for instance, supposing the enamel surface to be
white, the graduations, characters, or indications, should be black or of
some dark colour or prominent colour so as to be plainly perceptible.
The enamel surface does not extend to the edge of the stem, a margin
being left on both sides, as shewn in the Drawing.

page_text: Although the Drawing illustrates the Invention as applied to an
instrument having a straight or vertical stem it may be applied in like
manner to instruments or apparatus having round, oval, or otherwise
shaped stems; and although the Drawing shows the Invention applied to
a saccharometer it is applied in like manner to the other above-named
instruments.
Having now described the nature of the said Invention, and in
what manner the same may be performed, I declare that my Invention of
improvements in hydrostatic and certain other scientific instruments
relate to the portion or part of such instruments called the stem, and I
claim the application thereto of a surface of enamel or other similar
surface, coating, layer, or substance bearing graduations, characters,
figures, or other indications; the same being rendered readily perceptible
or visible, substantially as herein-before described, and for the purposes
above set forth.
In witness whereof, I, the said Arthur Nicholls have hereunto set
my hand and seal, this Twenty-second day of April, in the
year of our Lord One thousand eight hundred and seventy-
three.
0
Witness,
M. HENRY,
68, Fleet Street,
London, E.C.
ARTHUR NICHOLLS. (L.S.)