IMPROVEMENTS IN APPARATUS FOR REGISTERING THE STAND OF THERMOMETERS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Edwin Ambrose Brydges at the Office
of the Commissioners of Patents on the 11th October 1881. A communi-
cation from Professor Dr. Hugo Kronecker, of the City of Berlin aforesaid.
EDWIN AMBROSE BRYDGES, of the Firm of Brydges & Co., Engineers and
Patent Solicitors, of 73, Koeniggraetzer Str., in the City of Berlin, in the
Kingdom of Prussia and German Empire. "IMPROVEMENTS IN APPARATUS FOR
REGISTERING THE STAND OF THERMOMETERS." A communication from Professor
Dr. Hugo Kronecker, of the City of Berlin aforesaid.
This Invention relates to improvements in apparatus for automatically and
continuously registering the state of the thermometer, and so to obviate the tedious
process of having to note the variations of the same for scientific and other
purposes.
This registering is performed exactly and continuously, and so distinctly that
even the slightest alteration in the height of the quicksilver is communicated to
the paper employed for the purpose.
I attain this in the following manner:-
On the spindle of the hour hand of a suitable watch or clock I attach a frame in
such a
manner that it revolves with the same, and consequently makes one
revolution in twelve hours. Over the face of the clock I place a cover, which is
provided with a radial slot, in which a thermometer is snugly fitted, so that not
the slightest space remains between the slot and the thermometer, which is best
effected by grinding in the thermometer. The said cover must be so attached to
the front of the clock that no light can penetrate into the space between the cover
and the face of the clock, except through that part of the thermometer above the
quicksilver or other matter with which the bulb is filled. If paper sensitive to
light, such as is used for photographic purposes, be placed upon the frame under-
neath the cover the same will become affected by the light, which penetrates
through the part of the thermometer not occupied by the mercury or other matter
employed. As the paper is constantly on the move each variation of the thermo-
meter is continuously being photographed, and an exact register of every variation
of the height of the mercury or other matter in the thermometer is obtained; that
part of the paper affected by the light being blue, brown, or other suitable color,
TD 031

page_text: according to the chemicals employed, and the part covered by the quicksilver
being white.
The picture or diagram is rendered permanent by the treatment in a bath, as is
usual in photography, or by simple washing in water. The marks on the paper
appear either in circles or undulating lines, according as the quicksilver varies or
remains stationary.
In order to facilitate the reading of the registered marks, circles corresponding
to the degrees of the thermometer and their divisions can be drawn on the paper,
and the divisions of the time can be shewn by radial lines.
As is easy to perceive, this arrangement can be attached to any desired clock or
watch, and by these means the purpose of obtaining a regular motion of the paper
is most perfectly carried out.
'
A somewhat more complicated modification can be employed which has the
advantage of not depriving the clock of its original purpose of time-telling. To
effect this a ring of glass or other transparent material is inserted in the cover,
through which the figures on the clock and the extremities of the hands are
perceptible. It is however necessary to so alter the works of the clock that the
spindle of the hourhand works inside that of the minute hand, the contrary being
at present the case with the generality of clocks.
The sensitive paper is in the dark placed on the frame, and the whole apparatus
is exposed to light, either natural day light, or electric, or other suitable light.
After any desired period of time, at longest after one complete revolution of the
paper, .e., 12 hours, the paper can be removed and treated the same as in ordinary
photography, and can then be made use of in suitable manner, for instance, as
table for scientific lectures, etc.