and other Instruments.
Year: 1887

page_text: and other Instruments.
I, ISAAC JOSEPH, trading as Joseph Davis & Co., of Fitzroy Works, 6, Kennington
Park Road, in the County of Surrey, Manufacturing Opticians, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention relates to an improved registering and recording mechanism for
barometers, and consists in the combination with a duplex dial divided so that, say,
fiftieths of an inch can be indicated and read off without the use of a vernier, with a
series of smaller dials, by means of which the maximum or minimum pressures, or
their average, obtaining during any given terms, e.g., 12 or 24 hours, can be registered
upon the dial appropriated to said term, so that the instrument, while always indicating
the pressure obtaining at the moment of observation in the ordinary way, will present
a regular record of preceeding pressures for the sake of comparison being made, and
of the general tendency of the pressure obtaining during the term registered being
ascertained.
In order that my invention, and the means by which the same can be carried into
practical effect may be thoroughly understood, I will proceed to describe the same in
detail, referring in so doing to the accompanying drawing which is to be taken as part
of this specification and read therewith, and which illustrates the application of the
of the invention to a barometer.
A is the registering dial upon which are marked two arc-shaped scales, a and a¹,
each one a counterpart of the other. The scope of those illustrated is 2.9 inches
although I do not limit myself to this.
The two indices and care mounted upon a common axis d upon which they can
be independently adjusted by moving the loops and el projecting through the
grooves in the dial. Each loop is rigidly connected to the upper extremity of a bar
toothed on one edge and sliding in a vertical groove in the back of the case. A pinion
rotated by a key on the square end e of its axis engages with the toothed edge of the
said bar. A wide scale F, less finely divided than the two scales a, a, is marked upon
the dial between the two grooves, and positioned so that the indications of the
verniers, carried by the loops and respectively, correspond with those of the

page_text: indices and c. The dial as illustrated records the fact that yesterday's pressure
(maximum, minimum, or average) was 30.5 inches and that the pressure obtaining
to-day is 30:52 inches.
The advantage of having a scale in the centre of the dial with its vernier, and
having a legible indication of the day to which the reading refers close to this, is, that
the reading can be taken by anyone passing the instrument without his having to
minutely observe it, but if he desire to have the reading to a 50th of an inch he can
at once obtain said reading from the outside graduated scale.
G is a plate with seven semicircular apertures formed in it. A fixed pointer g
depends from the centre of each are. Behind each aperture is a dial g' divided with a
circular scale. A hole is made in each dial which can be turned by a key of suitable
section. The plate G is marked with the days of the week, each dial being thereby
appropriated to a particular day.
The drawing shews the invention as it stands on a Monday night: the seven small
dials furnish a record for the week ending the previous Saturday, and the pointer b
gives the pressure for the previous day, so that with the pointer a used for the current
day, the pressures of 9 days are recorded. On Tuesday morning the reading of the
index will he transferred to the Sunday dial behind the plate G, that of the index c
to the index b, and the index e will be free to be used for to-lay, i.e., Monday.
I do not confine myself to the exact number of dials behind the plate G, as this may
be varied or more than one plate and set of dials be used.
The seven recording dials on the plate G, and the two are shaped scales on the
dial A, as they are illustrated in the figure, give the following readings.
To-day. Monday
Yesterday. Sunday
Saturday
Friday
30.52 ins.
30-5
29.125
Thursday
Wednesday
Tuesday
Monday
Sunday
-28.825
28-23
29-26
28.5
28-575
30-5
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1. The combination of a series of independent recording dials with a dial having
one or two finely divided are shaped scales, substantially as described with reference to
the accompanying figure.
2. The combination of independently actuated verniers with a series of independently
2
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is
:―
1. The combination of a series of independent recording dials with a dial having
one or two finely divided are shaped scales, substantially as described with reference to
the accompanying figure.
2. The combination of independently actuated verniers with a series of independently
actuated recording diais, substantially as described with reference to the accompanying
figure.