IMPROVEMENTS IN GRAPHITE THERMOMETERS AND PYROMETERS
Year: 1878

page_text: LETTERS PATENT to Otto Steinle, of the Firm of Steinle and Hartung, of
Quedlinburg, Prussia, German Empire, for the Invention of "IMPROVEMENTS
IN GRAPHITE THERMOMETERS AND PYROMETERS."
PROVISIONAL SPECIFICATION left by the said Otto Steinle at the Office of
the Commissioners of Patents on the 19th June 1878.
OTTO STEINLE, of the Firm of Steinle and Hartung, of Quedlinburg, Prussia,
Gerinan Empire. "IMPROVEMENTS IN GRAPHITE THERMOMETERS AND PYROMETERS.”
My Invention has for its object the production of a thermometer and pyrometer
equal to the quicksilver thermometer for quick and sure indication, but with more
solidity in construction and facility of regulation.
And my Invention consists in the use of a bar of graphite or plumbago enclosed
within a tube, which tube being liable to change in length, by differences of tem-
perature, is caused to act on the indicator by means of a tube extending from
the top of the said bar to the indicator.
The instrument consists of a closed outer tube or case, which carries at its upper
end a box with the scale, and is connected at the lower end with a perforated tube,
the upper end of which has a guide or guides within the said outer tube and
supports the indicator, which is in communication with the bar of graphite or
plumbago by means of an inner perforated tube: This bar of graphite or plumbago
besides having great strength and porosity is very slightly liable to expansion, even
at great differences of temperature. When the tube in which the bar of graphite
or plumbago is enclosed becomes varied in length by a change of temperature the
said bar and the indicator will be correspondingly moved. The outer tube or
casing can vary in length without producing any effect on the indicator, and the
perforated tubes above referred to being surrounded by an adequate quantity of air
maintain an uniform temperature and length.
For regulating an instrument, in case after long use it should not go back to the
right temperature, it may be set as required by loosening a screw and inserting a
[Price 6d1

page_text: key, and bringing the indicator to position; as compared with a good quicksilver
thermometer. The indicator is so fitted on the top of the said perforated tube so
as to be independent of the box with the scale, and to admit of its being moved
and set as required by means of a crank.
By the combination of a bar of graphite or plumbago with a metal tube in the 5
manner stated temperatures may be measured up to twelve hundred degrees Celsius
(2192° Fahrenheit).
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Otto Steinle in the Great Seal Patont Office on the 17th December
1878.
OTTO STEINLE, of the Firm of Steinle and Hartung, of Quedlinburg, Prussia,
German Empire. "IMPROVEMENTS IN GRAPHITE THERMOMETERS AND PYROMETERS."
My Invention of "Improvements in Graphite Thermometers and Pyrometers"
has for its object the production of a thermometer and pyrometer equal to the
quicksilver thermometer in quick and sure indication, but with more solidity in
construction and facility of regulation.
And my Invention consists in the use of a bar of graphite or plumbago enclosed
within a tube, which tube being liable to change in length, by differences of
temperature, is caused to act on the indicator by means of a tube extending from
the top of the said bar to the indicator.
The instrument consists of a closed outer tube or case, which carries at its upper
end a box with the scale, and is connected at the lower end with a perforated tube,
the upper end of which has a guide or guides within the said outer tube and
supports the indicator, which is in communication with a bar of graphite or
plumbago by means of an inner perforated tube. This bar of graphite or plumbago
besides having great strength and porosity is very slightly liable to expansion, even
at great differences of temperature. When the tube in which the bar of graphite
or plumbago is enclosed becomes varied in length by a change of temperature the
said bar and the indicator will be correspondingly moved. The outer tube or casing
can vary in length without producing any effect on the indicator, and the perforated
tubes above referred to being surrounded by an adequate quantity of air maintain
an uniform temperature and length.
For regulating an instrument, in case after long use it should not go back to tho
right temperature, it may be set as required by loosening a screw and inserting a
key, and thereby bringing the indicator to position, as compared with a good quick-
silver thermometer. The indicator is so fitted on the top of the said perforated
tube as to be independent of the box with the scale, and to admit of its being
moved and set as required by means of a crank.
By the combination of a bar of graphite or plumbago with a metal tube in the
manner stated temperatures may be measured up to twelve hundred degrees Celsius
(two thousand one hundred and ninety-two degrees Fahrenheit).
Having thus stated the nature of the said Invention, 'I will proceed to describe

page_text: DESCRIPTION OF THE DRAWING.
A is the closed outer tube or case, which carries at its upper end the box B with
the scale, and is connected at its lower end, near the point U, with the perforated
tube C, which has a guide or guides near the point K, within the outer tube or
case A. This tube C supports the indicator, which is in connection or communication
with the bar of graphite or plumbago G, by means of the inner perforated tube D.
This bar of graphite or plumbago G, enclosed within the tubo J, besides having great
strength and porosity, is liable only to a small amount of expansion at great variations
of temperature. On the tube I becoming varied in length by a change of temperature
the bar of graphite or plumbago G will be moved, and with it the indicator through
the medium of the tube D. The outer tube or casing A can vary in length
without producing any effect on the indicator, while the tubes C and D being
perforated and surrounded by air maintain the same temperature and uniform
length.
For regulating an instrument, in case after long use it should not go back to the
right temperature, the screw at S is loosened by means of the key shewn detached
and the under end of the key inserted, and the indicator brought so as to show the
right temperature, according to a good quicksilver thermometer.
The plate P is put on the top of the tube C quite independently of the box B.
The indicator work is fixed to it by the screw X in such a manner that it can be
moved a little to the right or left by the crank near P, the centro of motion
being at X.
The instrument above described serving for a thermometer or pyrometer is
adapted to combine the quick and sure indication of the quicksilver thermometer
with solidity, elegance, and easy regulation, and is not liable to burst by sudden
variations of temperature. It has also the following comparative advantages:-It
need not be sunk so deep; it readily shows every variation of temperature without
setting the indicator; as usual, it works promptly up to twelve hundred degrees
Celsius (two thousand one hundred and ninety-two degrees Fahrenheit), and, lastly,
the internal parts are securely closed against steam and gases.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, I hereby declare that what I claim as of my
Invention is,
First. The use of a bar of graphite or plumbago in combination with a metallic
tube, for the purpose of measuring temperatures up to twelve hundred degrees
Celsius (two thousand one hundred and ninety-two degrees Fahrenheit), as herein-
before described.
Secondly. The independence of the outer tube or case and the box of the indicator
work, resulting from the combination therewith of the united tubes above the bar
of graphite or plumbago, as herein-before described.
And, lastly. The facility for setting the indicator by means of a crank, as herein-
before described.
In witness whereof, I, the said Otto Steinle, have hereunto set my hand and
seal the Sixth day of December in the year of our Lord One thousand
OTTO STEINLE. (L.B.)