IMPROVEMENTS IN BAROMETERS, THERMOMETERS, AND IN THEIR COMBINATION WITH WATCHES, CLOCKS, AND OTHER INSTRUMENTS
Year: 1868

page_text: LETTERS PATENT to Andrew Barclay, of Kilmarnock, in the County
of Ayr, North Britain, for the Invention of "IMPROVEMENTS IN
BAROMETERS, THERMOMETERS, AND IN THEIR COMBINATION WITH WATCHES,
CLOCKS, AND OTHER INSTRUMENTS."
Sealed the 18th September 1868, and dated the 23rd March 1868.
PROVISIONAL SPECIFICATION left by the said Andrew Barclay at
the Office of the Commissioners of Patents, with his Petition, on
the 23rd March 1868.
I, ANDREW BARCLAY, of Kilmarnock, in the County of Ayr, North
Britain, do hereby declare the nature of my said Invention of
"IMPROVEMENTS IN BAROMETERS, THERMOMETERS, AND IN THEIR COMBINATION
WITH WATCHES, CLOCKS, AND OTHER INSTRUMENTS," to be as follows, that
is to say :-
The essential object of the first part of this Invention consists in
combining a barometer with an ordinary pocket watch. The two

page_text: instruments so combined show the dial of the watch on one side of
the case and the dial of the barometer on the opposite side, or one
dial may be arranged for both purposes on one side of the instrument.
The construction of barometer which it is preferred to employ consists
of a thin hollow tube of a section somewhat elliptical or flat; this
tube is exhausted and fixed at one end to the case or to the framing
of the instrument, whilst the other end is free and attached by a link
to a lever which is moveable about a centre, and which at its opposite
end carries a toothed rack that gears into a pinion, on the axis of
which the indicating needle is fixed. By this arrangement as the
variations in the atmospheric pressure increase or diminish the com-
pression on the tube the tube itself expands and contracts, and the
motions thus produced in it are communicated to the link, thence
through the lever and rack to the pinion and indicating needle. To
provide for errors of indication which may occur when the instrument
is held in some positions an arm with a balance weight upon it is
placed on the side of the lever that carries the toothed rack and
opposite that side by which the lever is connected to the vacuum
tube.
In place of using a barometer constructed as herein-before described,
one constructed in a manner similar to that of a Bourdon vacuum
guage may be employed, the vacuum tube in which case is held at
the centre of its length instead of at one end. It is to be understood
that the barometer tube is placed in the case of the combined
instrument so as to encircle or surround the mechanism of the watch.
In place of using in the combined instrument a barometer
constructed as herein-before described an aneroid barometer may be
likewise employed. To obtain temperature indications the instrument
for that purpose is composed of a metallic tube which is filled with
mercury or other liquid.
The tube is connected to the indicating apparatus in the same
manner as in the barometer herein-before referred to, and as the
variations in temperature cause the expansion or contraction of the
mercury, so the indicating needle is moved to the right or left of the
thermometer scale; such instrument may be used in connection with
the combined barometer and watch or separately.
The second part of this Invention relates to the arrangement and
construction of instruments to be employed for ascertaining temperature,

page_text: and it is so adapted as to enable the obtainment of a diagram by
which the variations of temperature are indicated in such manner
that not only the variations themselves but the time or period of each
variation are accurately noted. The construction of thermometer
employed consists of a metallic tube filled with mercury or other
liquid, which on its expansion or contraction causes a movement of a
lever to which it is connected by a link in such manner that the
movements in the tube are communicated to it and thence by means
of a rack fixed at one end of the lever to actuate a pinion carrying
the indicating arm. The indicating arm is provided with a pencil,
the point of which bears against a graduated sheet of paper which is
maintained travelling at a uniform and known rate, so that as the
variations in temperature cause movements of the needle, the pencil
point with which it is mounted varies in position accordingly, and
upon the graduated travelling web or sheet of paper these variations
are depicted. In place of using a continuous length of paper for
depicting a diagram upon, a graduated disc may be employed, in
which case the pencil is caused to move from the centre towards the
circumference and back, the variations in temperature being recorded
by the diagram thus obtained upon the slowly revolving disc. The
travelling of the continuous length of paper as well as the revolution
of the disc may be effected by clockwork or any other mechanism
used for obtaining a travelling or rotatry motion.
When barometers constructed in the manner herein-before described
or any ordinary aneroid barometers are used diagrams of the variations
may be obtained by attaching a pencil to the indicating needle,
which acts against a travelling web or revolving disc of graduated
paper.