PYROMETERS AND THERMOMETERS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by the said William David Bowkett at
the Office of the Commissioners of Patents on the 16th September 1879..
WILLIAM DAVID BOWKETT, of Leeds, in the County of York.
IN PYROMETERS AND THERMOMETERS."
"IMPROVEMENTS
My improvements provide a means whereby any required temperature can be
taken, and if necessary the indication shown and registered at a distance from the
place, fluid, or object, the temperature of which is desired.
'
For taking or showing the temperature of an apartment or of any fluid or place
easy of access the instrument consists of a curved or bent metallic tube, filled with
fluid and perfectly closed. One end of this is fixed to a suitable bed or stand, and
the other is connected to a lever, the long arm of which points to an arc on which
is a scale of temperatures. The arc is slotted, the slot carrying two loose buttons,
so that on the pointer moving the buttons are pushed on towards one or other end
of the scale, showing the further position which the pointer has reached and thus
registering the maximum or minimum temperature.
Should it be required that the temperature be indicated at a distance from the
place the temperature of which is taken I connect the curved tube by means of a
small tube to a vessel, the whole being filled with a suitable fluid; on any variation
of temperature taking place the fluid contained in the curved tube or curved tube
and vessel will expand or contract, and in thus doing will increase or diminish the
pressure exerted on the sides of the curved tube or curved tube and vessel; this
will cause the arc of the curved tube to be increased or diminished, and thus com-
municate a movement to the lever, the extent of which will correspond with the
variation of temperature and will be indicated by the pointer on the arc.
Should the temperature required be taken exceed, say, 500° or 600°, I prefer

page_text: that the vessel shall contain a gaseous fluid and shall be connected, as before
described, by a fine tube with the curved tube, which will still be filled with a
suitable liquid, so that the pressure produced by the expansion of the gas in the
vessel shall be indicated on the index arc. The air contained in the vessel, being
sufficiently elastic to be influenced by barometrical changes when preferred, the
index arc may have an adjusting means, so that its position can be altered in.
accordance with barometrical changes.
The pointer may be mounted or carried on a shaft, which may be of any desired
length, for the purpose of registering the movement of the same at any required
distance or direction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William David Bowkett in the Great Seal Patent Office on the
16th March 1880.
WILLIAM DAVID BOWKETT, of Leeds, in the County of York. "IMPROVEMENTS
IN PYROMETERS AND THERMOMETERS."
My improvements provide a means whereby any required temperature can be
taken, and if necessary the indication shown and registered at a distance from the
place, fluid, or object, the temperature of which is desired.
For taking or showing the temperature of an apartment or of any fluid or
place easy of access, the instrument consists of a curved or bent metallic tube filled
with fluid and perfectly closed. One end of this is fixed to a suitable bed or stand,
and the other is connected to a lever, the long arm of which points to an are on
which is a scale of temperatures. The arc is slotted, the slot carrying two loose
buttons, so that on the pointer moving the buttons are pushed on towards one or
other end of the scale, showing the furtherest position which the pointer has
reached, and thus registering the maximum or minimum temperature.
Should it be required that the temperature be indicated at a distance from the
place, the temperature of which is taken, I connect the current tube by means of a
small tube to a vessel (which vessel is placed in the situation whose temperature is
required), the whole being filled with a suitable fluid; on any variation of
temperature taking place the fluid contained in the curved tube or curved tube
and vessel will expand or contract, and in thus doing will increase or diminish the
pressure exerted on the sides of the curved tube or curved tube and vessel;
this
will cause the arc of the curved tube to be increased or diminished and thus com-
municate a movement to the lever, the extent of which will correspond with the
variation of temperature and will be indicated by the pointer on the arc; or the
pointer may be mounted or carried on a shaft, which may be of any desired length,
for the purpose of registering the movement of the same at any required distance
or direction.
Should the temperature require to be taken exceed, say, 500° or 600°, I prefer
that the vessel shall contain a gaseous fluid and shall be connected, as before
described, by a fine tube with the curved tube, which will still be filled with a
suitable liquid, so that the pressure produced by the expansion of the gas in the
vessel shall be indicated on the index arc, the air contained in the vessel being
sufficiently elastic to be influenced by barometrical changes; when preferred the
index arc may have an adjusting means, so that its position can be altered in
accordance with barometrical changes.
And in order that my Invention may be more completely understood reference
is given to the accompanying Drawings and to the letters and marks thereon,
DESCRIPTION OF DRAWINGS.
Fig. 1 is a front elevation; Fig. 2, a transverse section through A, B, Fig. 1;
Fig. 3 is an elevation shewing a modification of curved tube and its attachments.
a is the curved or bent metallic tube filled with fluid, one end 6 of it is fixed to
a suitable stand c, the other end d is attached by a link e to the arm or pointer f
mounted on the stud g. The stand c is surmounted with a metallic arc h, the
surface of which is divided into degrees to which the extremity fl of the arm f
points in accordance with the corresponding temperature of the tube. I provide
buttons or sliding pieces i and j, shewn in dotted lines; these are moved respec-
tively right and left by the arm or pointer f, and denote the highest and lowest
temperature; these buttons or sliding pieces i and ; are set or removed to the

page_text: middle of the arch by hand. But I find that the arms or pointers k and 1, radi-
ating on the stud g, work better in practice. Although I have shewn the arm or
pointer f, also the arms or pointers and on the stud g, I would have it under-
stood that instead of the stud g a shaft m, partially shewn in dotted lines, may be
prolonged and the temperature indicated at any suitable distance from the metallic
tube a.
Fig. 3 represents an adaptation of the metallic tube a, for indicating high
temperatures, it being fixed at b and free to move at d. The indicating arms or
I attach a small tube n to the metallic
pointers are arranged as shewn for Fig. 1.
tube a at b, which communicates with the vessel o, this being constructed of
platinum enclosed in "crucible composition clay." The tube n which connects this
vessel o with the metallic tube a is of a very fine bore. The metallic tube a is
filled with glycerine or linseed oil, and the vessel o with common air or other
suitable gas. It will be readily understood that on the vessel o becoming heated
the air or gas therein contained will expand and exert a pressure, putting in motion
thereby the free end d of the metallic tube a, to which is connected the herein
before mentioned indicating arm f. In order to prevent over heating of the tube a
the tube n is surrounded in some portion of its length with a small vessel p, which
is filled with water so that the portion above cannot exceed the boiling point.
The object of the bent tube a being filled with liquid is to prevent the gas from the
vessel o flowing into the tube a, and so over heating the curved tube a or con-
ducting off too rapidly the heat.
The above described arrangement of metallic tube a may be employed for regu-
lating temperatures by being attached at its loose end to the opening or closing
part of apparatus employed for the admission or shutting out warm or cold air,
and thereby maintaining a steady temperature in any closed space, or round, or
apartment.
Having now described the nature of my said Invention, and described with the
aid of Drawings how the same may be carried into practice, I would have it under-
stood that I do not limit myself to the precise details or configuration of the parts
I have described and shewn, as the same may be varied or modified without
departing from the nature of my said Invention; but what I do claim and desire to
be secured to me by Letters Patent is,-
The arrangement, construction, and combination of parts forming the thermometer
or pyrometer, substantially as herein set forth.
In witness whereof, I, the said William David Bowkett, have hereunto set
my hand and seal, this Fifteenth day of March, in the year of our Lord
One thousand eight hundred and eighty.
W. D. BOWKETT. (L.S.)