AN IMPROVED PYROMETER
Year: 1862

page_text: LETTERS PATENT to Oscar Fredrik Byström, of Stockholm, in the King-
dom of Sweden, Captain of Artillery, for the Invention of "AN IMPROVED
PYROMETER."
Sealed the 16th December 1862, and dated the 5th July 1862.
PROVISIONAL SPECIFICATION left by the said Oscar Fredrik Byström-at
the Office of the Commissioners of Patents, with his Petition, on the
5th July 1862.
I, OSCAR FREDRIK BYSTRÖM, of Stockholm, in the Kingdom of Sweden,
Captain of Artillery, do hereby declare the nature of the said Invention for
"AN IMPROVED PYROMETER," to be as follows:-
This Invention relates to an improved pyrometer which the Inventor. calls
the "hydro-pyrometer," from the fact that the temperature of the furnace,
retort, muffle, or other heating arrangements or media to be tested is indicated
by the proportionate amount of heat imparted to a known weight of water by
a body immersed therein, such body having been previously heated in the
furnace, retort, or muffle to be tested to an equal temperature therewith. The
"hydro-pyrometer" consists essentially of a closed vessel containing a known
weight of water, and surrounded by a wooden or other casing to prevent loss
of heat by radiation. Into this vessel are fitted a funnel mouth connected
with a wire cage inside the vessel capable of being rotated or agitated therein

page_text: and an ordinary thermometer. A plug is fitted to the bottom of the vessel
to let out the water when desired.
In connection with and forming part of the apparatus there is a ball of
platinum or other suitable substance capable of withstanding the highest
temperature to the testing of which the apparatus is to be applied. This ball
when using the apparatus is introduced into the furnace, retort, or muffle, and
allowed to remain therein until it has attained an equal temperature therewith.
It is then released from the rod or holder by which it was introduced, and
allowed to escape instantly from the furnace by a tube or exit passage fitted
for that purpose thereto, and provided with a self-opening and closing valve
or stopper at its outer end. As the heated ball descends it opens the valve
and drops into the funnel mouth of the vessel placed there to receive it, and
finally enters the cage above referred to, and becomes immersed in the water.
The funnel mouth having been closed the cage is rotated a few times, and the
vessel gently agitated or shaken so as to disperse the heat of the ball equally
throughout the water in the vessel. By observing the temperature of the
water by the thermometer before and after the above mentioned procedure,
the difference will be obtained, and this difference or variation in temperature
enables the exact, or nearly exact, temperature of the furnace, retort, or muffle,
to be arrived at by comparative experiment.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Oscar Fredrick Byström in the Great Seal Patent Office on
the 5th January 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, OSCAR
FREDRICK BYSTRÖM, of Stockholm, in the Kingdom of Sweden, Captain of
Artillery, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of July, in the year of our Lord One
thousand eight hundred and sixty-two, in the twenty-sixth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Oscar Fredrick Byström, Her special license, that I, the said Oscar Fredrick
Byström, my executors, administrators, and assigns, or such others as I, the said
Oscar Fredrick Byström, my executors, administrators, or assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ire-
T

page_text: land, the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
PYROMETER," upon the condition (amongst others) that I, the said Oscar
Fredrick Byström, my executors or administrators, by an instrument in writing
under my hand and seal, or under the hand and seal of one of them, 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 Oscar Fredrick Byström, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:-
My said Invention relates to an improved pyrometer which I call the "hydro-
pyrometer" from the fact that the temperature of the furnace, retort, muffle,
or other heating arrangements to be tested is indicated by the proportionate
amount of heat imparted to a known weight of water by a body immersed
therein, such body having been previously heated in the furnace, retort, or
muffle, to be tested to an equal temperature therewith. The "hydro-pyrometer "
consists essentially of a closed vessel, containing a known weight of water, and
surrounded by a wooden or other casing to prevent loss of heat by radiation.
Into this vessel are fitted a funnel mouth connected with a wire cage inside
the vessel capable of being rotated or agitated therein, and an ordinary
sensitive thermometer; a plug is fitted to the bottom of the vessel to let out
the water when desired.
In connection with and forming part of the apparatus there is a ball of
platinum or other suitable substance capable of withstanding the highest
temperature, to the testing of which the apparatus is to be applied. This ball
when using the apparatus is introduced into the furnace, retort, or muffle, and
allowed to remain therein until it has attained an equal temperature therewith.
It is then released from the rod or holder by which it was introduced, and
allowed to escape instantly from the furnace by a tube or exit passage fitted
for that purpose thereto, and provided with a self-opening and closing valve,
or stopper at its outer end. As the heated ball descends it opens the valve
and drops into the funnel mouth of the vessel, placed there to receive it and
finally enters the cage above referred to, and becomes immersed in the .water.
The funnel mouth having been closed, the cage is rotated a few times, and the
vessel gently agitated, or shaken, so as to disperse the heat of the ball equally
throughout the water in the vessel. By observing the temperature of the

page_text: water by the thermometer before and after the immersion of the ball, the
difference will be obtained, and this difference or variation in temperature
enables the exact or nearly exact temperature of the furnace, retort, or
muffle to be arrived at by comparative experiment.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
Figures.
.
Figure of the Drawings represents a full sized vertical section of my
'hydro-pyrometer;" Figure 2 is a corresponding plan of the same, partly in
section; and Figure 3 represents, on a smaller scale, the mode of applying
and using the "bydro-pyrometer." In Figures 1 and 2, A is the closed vessel
containing the known weight of water; B a wooden jacket or casing; C is a
funnel mouth, capable of being rotated in its socket D by the small pin or
handle E; F is a wire cage or grating for catching the platinum or steel ball
G; His a sensitive thermometer; and I is an aperture or nozzle, fitted with
a plug for discharging the contents of the vessel A. In Figure 3, K
represents the wall of a furnace, in which is built a passage L, terminating
at the back end in a plumbago crucible M, which is inside the furnace. A
small bridge N is formed inside this crucible immediately in front of a passage
O, leading by the inclined pipes P back to the front or outside of the furnace
wall. At this end of the pipes there is fitted a self-closing valve Q for the
purpose of excluding air.
The platinum or steel ball G, of a known weight, is introduced into the
crucible M, as shewn in Figure 3, in any convenient manner, which will
admit of its being readily released and allowed to descend the passage P after
it has attained the same temperature as the interior of the furnace. One of
the modes I propose to adopt for this purpose is to have a hole made through
the ball, and to place the ball on the end of a long rod R (Figure 3), by
which it is carefully conveyed into and retained within the crucible M, the
rod being then allowed to rest upon the bridges or supports N and S. The
front orifice of the passage L is then closed by a wedge T, and luted up to
exclude cold air. The ball having been allowed to remain inside the crucible
M, a sufficient time to ensure its attaining an equal temperature with the
furnace itself, it is released by withdrawing the rod R, the bridge N serving
to force the ball from off the end of the rod, and allow it to fall down the
passage P, till, by striking the weighted valve Q, it opens the same, and drops
into the funnel mouth C of the apparatus, which has been previously charged

page_text: with a known weight of water. By observing the temperature of the water
before (t) and after (¹) the immersion of the heated ball, the difference
(tt) will be obtained, which enables the approximate temperature of the
furnace to be arrived at either by comparative experiment, or by the following
formula and table:

page_text: The x temperature corresponding to 2.60 in the steel column of the Table
is 660°. The final temperature of the water is 17°, which, added to 660°,
gives 677° the temperature of the oven, hence x + t¹=677°, the temperature
The
temperature corresponding
The final temperature t¹
The temperature of the oven (x+1¹) -
1550°
20°
1570°
In ovens or furnaces of the highest temperatures, the "hydro-pyrometer" is
used without the crucible or muffle M herein-before referred to and illustrated
on Figure 3; Figure 4 shows this mode of application. The passage P for the
escape of the ball is placed as herein-before described, with the exception that
the muzzle of this pipe is partly situate inside, the oven being protected by
fireproof bricks, as shown. The upper pipe L is made to terminate a short
distance from the inside of the wall K of the furnace, and the passage is
continued in fire-clay as.shewn, to protect the end of this pipe. The rod R
has a screw thread upon it at the part where it passes through the cap or
cover T, which closes air-tight the front or outer end of the pipe L. The ball G
is contained in a species of cup or spoon formed on the inner end of the rod R,
being held immediately over the muzzle 0 of the inclined passage P. In order
to release the ball it is simply necessary to reverse or turn the rod R in the
cap or cover T, which may be done without leaving any inlet for cold air,
whereupon the heated ball G drops out of the cup or spoon into the passage P,
and thence into the water vessel, as herein-before described.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or or may be used or

page_text: carried into effect, I would observe in conclusion, that what I consider to be
novel and original and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,-
First, the general construction and arrangement of pyrometer, as herein-
before described.
Second, the peculiar system or mode of ascertaining the temperature of
furnaces, retorts, muffles, and other heating arrangements, as herein-before
described.
In witness whereof, I, the said Oscar Fredrick Byström, have to this
my Specification set my hand and seal, this Twenty-ninth day of
December, One thousand eight hundred and sixty-two.
OSCAR FREDRICK BYSTRÖM. (L.S.)