An Improved Thermometer.
Year: 1896

page_text: ALEXANDER LURASCHI 15 Cross Street, Hatton Garden, London. Chemical
and Experimental Glass Blower do hereby declare the nature of this invention to
be as follows:-
My invention consists of a piece of glass suitable for my purpose & it is carried
out by bending the same into a suitable form, by preforence in the shape of a cork
screw or spiral & inserting the same in a piece of cylinder which is to form the bulb
of the thermometer and well fusing them together & then joining a thermometer
stem to the bulb in such a way that the bore of the cork screw spiral & the
thermometer stem exactly meet & thus form a continual bore from extreme end of
thermometer stem to extreme end of spiral. The end of the latter is left open thus
forming a communication with interior of the bulb. I then fill the bulb with a
suitable fluid & having expelled all the air from the bulb 1 insert a
quantity of mercury to the proper position. Then I fill the thermometer stem
with fluid into which I put an index which will rise with the temperature & there
remain showing the highest point reached.
This construction is advantageous for electrical & other thermometers requiring
a large round bore without a large & heavy bulb which would be the case if the
bulb was filled entirely with mercury as in the ordinary way.
A. LURASCHI.
An Improved Thermometer.
I, ALEXANDER LURASCHI, of 15 Cross Street, Hatton Garden, London,
Chemical and Experimental Glass Blower, 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 thermometers in which a largo round bore is required
and consists of a novel construction whereby a large and heavy bulb is dispensed
with which would be required if the bulb were entirely filled with meroury in the
ordinary way.
My invention is illustrated in the accompanying drawing in which Fig. 1 is a
sectional elevation of a thermometer constructed according to my invention, and
Fig. 2 is a section of the lower portion thereof.
a is the thermometer tube and is the bulb which latter instead of having its
space communicate directly with the lower end of the hore of the tube a as
heretofore, is made to cominunicate with the upper end of a spiral tube c whose
lower end is connected to the lower end of a tube c' passing axially through the
spiral tube c and connected at its upper end with the bore of the tube a.

page_text: The bulb b and the upper part of the spiral tube c are supplied with a suitable
fluid and the lower part of the spiral tube 'c, the tube c' and the lower part of the
tube a are supplied with mercury.
The method in which I proceed to construct such a thermometer is as
follows:-
I take a length of glass tubing suitable for my purpose and by the aid of heat
I bend the same into the shape of a cork screw or spiral c and connect it with a
straight tube c' extending axially through the spiral. I then insert the same into
a piece of cylinder glass which is to form the bulb & of the thermometer and well
fuse them together, the upper end of the straight tube o' being connected to the
upper end of the bulb 6. After this I take a length of tubing to form tho
thermometer stem az and fuse the same to the upper end of the bulb b in such a way
that the bores of the tube c' and the thermometer stem a exactly ineet and thus
form a continuous bore from the extreme end of thermometer stem a to the
extreme end of the spiral c. The end of the latter is left open thus forming a
communication with the interior of the bulb. I now close the lower end of the
bulb by fusion.
I then fill the bulb with a suitable fluid and having expelled all the air from the
bulb 1 insert a quantity of mercury to the proper position. Then I fill the
thermometer stem a with fluid into which I place an index which will rise with
the temperature and there remain showing the highest point reached.
The above construction is advantageous for electrical and other thermometers
requiring a large round bore without a large and heavy bulb which would be the
case if the bulb wore filled entirely with mercury as in the ordinary way.
By these means I save weight of mercury and thereby to a large extent, avoid
risk of breakage.
Having now 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 :-
1. The improved thermometer constructed substantially as heroin shown and
.described.
2. A thermometer having within the bulb a spiral tube open at its uppor end to
the interior of the bulb and communicating at its lower end with the bore of the
thermometer stem, the thermometer being supplied with a suitable fluid and with
a small proportion of mercury substantially as and for the purpose herein set
forth.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.