IMPROVEMENTS IN CLINICAL THERMOMETERS
Year: 1884

page_text: I, JAMES JOSEPH HICKS of Hatton Garden in the County of Middlesex
Meteorological Instrument Manufacturer do hereby declare the nature of my
invention for "IMPROVEMENTS IN CLINICAL THERMOMETERS" to be as follows:-
This Invention relates more particularly to that class of clinical thermometers in
which the appearance of the bore is magnified by the peculiar shape of that portion
of the tube through which the mercurial column is seen and which are generally
known as lens front clinical thermometers and my invention consists of improvements
whereby the difficulty hitherto experienced of selecting the right line of view is
avoided whilst at the same time the divisions and figures are also made much more.
clearly visible.
"Lens front" clinical thermometers as heretofore made have been formed of
tubing drawn with a strip of white enamel along the back of the bore but with the
remainder of the tube of clear glass, this being so and the "lens front" being very
narrow and having no perceptible boundary or margin but running imperceptibly
into the sides of the tube the difficulty above referred to was experienced in
selecting the right line of view whilst the divisions and numbers being engraved
on the clear glass without any white enamel immediately under them it was in
some cases difficult to see such divisions and figures.
According to my Invention I form the tubing of which the thermometers are
made with a strip of white enamel extending all round the back and sides of the
tubing but leaving only the narrow "lens front" or line of sight of clear glass by
these means the user of the thermometer is at once guided to the correct line of
view. I also engrave the divisions and figures at the sides of the "lens front
the white enamel whereby such divisions and figures are made much more clearly
visible than when engraved on the clear glass.
"
over
The improvements are also applicable to clinical thermometers made without the
lens front above referred to,
Dated this 26th day of January 1884
:

page_text: I JAMES JOSEPH HICKS of Hatton Garden in the County of Middlesex,
Meteorological Instrument Manufacturer do hereby declare the nature of the
said Invention for IMPROVEMENTS IN CLINICAL THERMOMETERS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The Invention relates more particularly to that class of clinical thermometers
in which the appearance of the bore is magnified by the peculiar shape of that
portion of the tube through which the mercurial column is seen and which are
generally known as "lens front" clinical thermometers and my invention consists
of improvements whereby the difficulty hitherto experienced of selecting the right
line of view is avoided whilst at the same time the divisions and figures are also
made much more clearly visible.
"Lens front" clinical thermometers as heretofore made have been formed of
tubing drawn with a strip of white enamel along the back of the bore but with
the remainder of the tube of clear glass, this being so and the "lens front" being
very narrow and having no perceptible boundary or margin but running
imperceptibly into the sides of the tube the difficulty above referred to was
experienced in selecting the right line of view whilst the divisions and numbers
being engraved on the clear glass without any white enamel immediately under
them it was in some cases difficult to see such divisions and figures.
According to my Invention I form the tubing of which the thermometers are
made with a strip of white enamel extending all round the back and sides of the
tubing but leaving only the narrow "lens front" or line of sight, of clear glass;
by these means the user of the thermometer is at once guided to the correct line of
view;
I also engrave the divisions and figures at the sides of the "lens front" over
the white enamel' whereby such divisions and figures are made much more clearly
visible than when engraved on the clear glass.
The improvements are also applicable to clinical thermometers made without the
lens front above referred to.
My Invention is represented in the accompanying drawings in which Figures 1
and 2 are cross sections of clinical thermometers representing respectively a." lens
front" clinical thermometer and an ordinary round tube clinical thermometer and
Figure 3 is a face view of part of the clinical thermometer shown in section at
Figure 2.
These drawings, as will be seen are made to a very large scale in order to show
the invention clearly.-a represents the body of the thermometer which is made of
clear glass, 6 is the bore and c is a strip of enamel extending all around the back
and sides of the thermometer except along only a narrow space c¹ which is of clear
glass which forms the correct line of sight through which the bore b is to be
viewed.
In Figure 1 this space c¹ of clear glass is immediately under the lens front a¹ and
thereby directs the user to the correct line through which the bore b can be seen
through the "lens front" a. In Figure 2 there is no "lens front" but the space cl
of clear glass also directs the user to the correct line of sight.
The divisions and figures are engraved on the sides of the line of sight over the
white enamel as shown or in any other suitable manner.
In producing tubing to be employed in the manufacture of clinical thermometers
of the character above described, I have found the following method of work to
produce good results. The workman takes out of the glass pot on the end of his

page_text: blow tube or pontil a suitable quantity of metal (clear glass) he then rolls this lump
until it assumes somewhat the shape of a pear; an iron rod is then dipped into a
pot containing white enamel and a suitable quantity of enamel is taken up on the
end of such rod to form a thin coating thereof around the lump of clear glass; this
lump of white enamel while in a plastic state is rolled on a steel plate into suitable
form and while still connected with the rod it is flattened by forcing down thereon
another steel plate. This sheet of white enamel is then, if necessary, trimmed to a
suitable shape to pass round the lump of clear glass on the blow tube except along
a narrow space longitudinally thereof. The lump of clear glass is then rolled on
this sheet of enamel so as to be covered thereby except along a comparatively
narrow line lengthwise thereof. The entire is then re-heated, after which it is
again rolled on the steel plate to ensure the complete adhesion of the enamel to
the lump of clear glass and to produce the desired shape, after this the workman
blows through the blow tube into the lump to produce a space therein, he then if
necessary reheats the same and swings it in the air to elongate the glass and
consequently the bore. The bore at this stage being round, he now proceeds to roll
the glass on the steel plate till he reduces the bore to the size desired, before
flattening the same. To flatten the bore he lays the 'tube on to a steel plate with
its narrow clear face uppermost, he then brings another steel plate down on to the
clear face and so flattens the bore that its widest face is seen through the face of
clear glass.
The workman now dips the enamel coated flat tube into the pot containing clear
glass and takes up sufficient metal thereon to form a thin coat of clear glass around
the same, he then rolls it to make it perfectly round outside after which he reheats
it and the tubing is then drawn in the usual way.
The process as above described is employed to produce the section of tubing
shown at Figure 2 the same process is employed to produce the section of tubing
shown at Figure 1 except that just before drawing the tubing the front or face of
clear glass is slightly pressed into a V shaped mould to produce the lens front; it
is then re-heated and the tubing drawn therefrom in the usual manner.
Having thus particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:
Constructing clinical thermometers with a body of clear glass surrounded by a
strip of white enamel extending all round the back and sides of the tubing except
along a narrow space of clear glass forming the correct line of sight through which
the bore is to be viewed, and engraving the divisions and figures at the sides of
such narrow space over the white enamel substantially as herein shown and
described and for the purpose stated.