AN IMPVED INSTRUMENT POR INDICATING ATMOSPHERIC CHANGES
Year: 1865

page_text: LETTERS PATENT to Henry Augustus Clum, of Rochester, in the
United States of America, now residing in Fleet Street, in the City of
London, Professor of Natural Science, for the Invention of "AN IMPROVED
Sealed the 16th January 1866, and dated the 20th July 1865.
PROVISIONAL SPECIFICATION left by the said Henry Augustus Clum at
the Office of the Commissioners of Patents, with his Petition, on the
20th July 1865.
I, HENRY AUGUSTUS CLUM, of Rochester, in the United States of America,
now residing in Fleet Street, in the City of London, Professor of Natural
Science, do hereby declare the nature of the said Invention for "AN IMPROVED
INSTRUMENT POR INDICATING ATMOSPHERIC CHANGES," to be as follows:-
My object is to produce an instrument highly sensitive to atmospheric
changes.
My Invention consists, 1st, in the combination of an air or gas chamber. or
chambers, with a buoy resting in or connected with a mercurial column in
such manner that the said chamber or chambers will be acted on to a degree
by the atmosphere surrounding them.
2nd, the arrangement of the buoy and the rod connected therewith in com
bination with the contracted bottom of the mercury tube, in such a manner
as to render the action of the mercury regular and uniform.

page_text: ord, the method and means by which the air or gas chamber or coamben
"are connected with the buoy.
4th, the arrangement of the spring, cord, or chain in connection with the
loop or yoke and the pulley giving motion to the circular moving hand.
5th, the arrangement of parts whereby the two hands on the dial plate are
-carried; all as hereafter described.
In the accompanying Drawings Figure'l is a perspective view of my
improved instrument, and Figure 2 is a central vertical section.
As represented in the Drawings a base A is provided, which is capable of
being adjusted, together with the parts it supports, in an exactly vertical
position by any desirable means, that shown being screws a, a, connected with
the feet. Centrally in this base is situated a cistern B for containing
mercury or other liquid, having a cover c, and from this cistern extends ver-
tically to a suitable height a tube C, in which the mercury rises in vacuum.
In the cover c of the cistern screws a box or case D, in which rests an
indicator, the stem of which passes down through the lower end of the box,
and has secured to it a float that rests upon the top of the mercury within
the cistern. As the mercury rises or falls the indicator will correspondingly
rise or fall and exhibit to the eye the height of the mercury. In order to
raise or lower the mercury to the zero point (at which it should stand) the
bottom g of the cistern is made of leather, rubber, or other equivalent flexible
material, which is adjusted up or down by any convenient means, that
represented being a screw h. It is obvious that as the mercury rises higher
or lower in the tube C by reason of variations in the atmosphere, that by the
means above described will enable that in the cistern to be raised or lowered
exactly to the zero point. In the tube C rests a buoy J, also a simple tube air-
tight, and which floats in the mercury as indicated. To the lower end of the
buoy is jointed a rod i, preferably made of steel, which passes down loosely
through a nut k at the end of the tube C, and screws or otherwise attaches to
a cross bar l. This cross bar unites at its extremities with rods m, m,
extending upwards through the cover of the cistern, and attached at their
upper ends to a simple ring n, which they support. The ring is provided with
a number of arms o, o, o, which support air or gas tight chambers E, E,
which from their office I denominate "balloons."
In the Drawings these balloons are represented as of cylindrical form and
of considerable length, being supported at their upper ends by arms p, p,
extending downward from an air-tight globe or crown chamber' F, whose
office is similar. The tops of the balloons are shown as formed into globes
9, 2, which form part of them. Thus it will be perceived that the whole
'

page_text: weight of the balloons and the crown chamber is supported by the buoy J'
within the mercury tube, and consequently will rise and fall with it. The
buoy and the balloons and crown chamber have a close and intimate action.
upon each other. As the mercury rises or falls by reason of atmospheric-
changes, the buoy will rise and fall, and consequently also the balloons and
crown chamber.. The balloons and crown chamber are made very thin and
light, and are filled preferably with air, though, if desired, they may be filled
with gas.. Thus they are nearly balanced or suspended in the outer atmo-
sphere, and any perceptible change in the density or rarefaction of the latter:
will have a tendency to correspondingly raise or fall the air chambers; which
are exceedingly sensitive owing to the unchangeability of the air within.them: .
The advantage secured is that the sensitiveness of the air chambers has a
tendency to overcome the inertia. of the mercury within the tube and make it.
much more sensitive than would otherwise be the case, and it is upon this
fact that the great value of my device rests.. The employment of the air
chambers overcomes in a great degree the friction and sluggishness in the
action of the mercury.. This same effect will be produced if the air chambers
are made of a different form, situated in a different. position, or even made in
a single body.
I do not confine myself to any form, position, or number; für instance,.
the chambers or chamber might be suspended either beneath or above the
mercurial.columu, provided the proper connection were made with the buoy:
within the tube, and still the same effect would be produced. I prefer the
arrangement described, simply because it is convenient and gives a pleasing:
ornamental effect. For this purpose, and also to protect the parts from dirt,.
I also prefer to employ a glass cover I.as shown. The nut K.at the lower end
of the tube C, by having a. contracted passage for the rod i through, has a
tendency to give a greater steadiness to the action of the mercurial.column in
the tube. To the top of the mercury tube C is secured a cap K, from which..
extend arms for the purpose cf. attaching the dial M.. From the top of the
cap also projects a spindle r, over which slides a.bearing s. of the framework.
of the air chambers. as the latter rise and fall. This bearing. is preferably.
provided with several small friction rollers t,.t, which lessen the friction and
allow the bearing to play up and down with the greatest ease and freedom..
The crown chamber is provided with a socket u. to slide over the spindle when.
the air chambers fall. To an arm of. the ring at the bottom is secured a.
rod N, which extends upward, and has its upper. end formed into an. oblong
loop or yoke v that encircles a grooved pulley O,.the axis of which at the inner
end rests in a jewelled bearing, while its outer end sustains the large hand

page_text: that moves around the dial. Longitudinally across this loop or yoke is strung
a cord or chain w, which is wound once or more around the pulley, and has
at one end a small spring to draw it constantly taut. The rod N is pro-
vided with a projecting arm, which passes. outward through a vertical slot 3 in
the dial, and has attached to it a cross hand R. The dial has marked upon
its face two scales, one up and down on the margin of the slot z, and the
other circular around the edge. The former is to indicate whole inches, and
the latter subdivisions. As the rod N moves up or down with the air
chambers, the cross hand R. indicates the inches upon the vertical scale of the
dial. The same up-and-down movement will also give motion to the pulley O
by reason of the cord or chain w, and consequently the hand P will pass
around the circular scale and indicate the subdivisions of inches.
The instrument I have produced is extremely sensitive, and will foretell
with great accuracy the approach of storms and any variations in the atmo-
sphere. The air chambers act similarly to a cloud in the atmosphere, being
carried up or down in proportion to the density of the medium that supports
them. The object of this balloon appendage to the mercurial column is to
take advantage of the small premonitory atmospheric pulsations always pre-
ceding more marked fluctuations of the barometer incident to, storms.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Augustus, Clum in the Great Seal Patent Office on
the 20th January 1866.
TO ALL TO WHOM THESE PRESENTS. SHALL COME, I, HENRY
AUGUSTUS CLUM, of Rochester, in the United States of America, now residing
in Fleet Street, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent,, bearing date the Twentieth day of July, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-ninth year of Her reign.
did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Augustus Clum, Her special licence that I, the said Henry
Augustus Clum, my executors, administrators, and assigns, or such others
as I, the said Henry Augustus Clum, my executors, administrators, and
assigns, should at any time agree with, and no. others, from time to time,
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
ef Great Britain and Ireland, the Channel Islands, and Isle of Man, an

page_text: Invention for AN IMPROVED INSTRUMENT FOR INDICATING ATMOSPHERIC
CHANGES,"
upon. the condition (amongst others) that I, the said Henry
Augustus Clum, my executors, or administrators, by an instrument in writing
under my, or their, or one of their bands and seals, 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 Henry Augustus Clum, 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 thereof, reference being had to the Drawings hereunto
annexed, that is to say :-.
My object is to produce an instrument highly sensitive to atmospheric
changes.
My Invention consists, first, in the combination of an air or gas chamber
or chambers with a buoy resting in or connected with a mercurial column in
such manner that the said chamber or chambers will be acted on to a degree
by the atmosphere surrounding them.
Second, the arrangement of the buoy and the rod connected therewith in
combination with the contracted bottom of the mercury tube, in such a
manner as to render the action of the mercury regular and uniform.
Third, the method and means by which the air or gas chamber or chambers
are connected with the buoy.
Fourth, the arrangement of the spring, cord, or chain in connection with
the loop or yoke and the pulley giving motion to the circular moving hand.
Fifth, the arrangement of parts whereby the two hands on the dial plate
are carried; all as hereafter described.
In the accompanying Drawings Figure 1 is a perspective view of my
improved instrument, and Figure 2 is a central vertical section; Figure 3,
a side sectional elevation of the dial portion of the instrument, together with
the contiguous operating parts; Figure 4, a face elevation of the dial plate ;
Figure 5, a plan of the top of the instrument looking downward from the
dotted line x, x, Figure 2; Figure 6, a sectional view of the zero float. Like
letters of reference indicate corresponding parts in all the Figures:
:
As represented in the Drawings a base A is provided, which is capable of
being adjusted, together with the parts it supports, in an exactly vertical
position by any desirable means, that shown being screws a, a, connected with
the feet. Centrally in this base is situated a cistern B for containing mercury
.

page_text: or other liquid, having a cover c, and from this cistern extends vertically to a
similar height a tube C, in which the mercury. rises in vacuo. In the cover c
of the cistern screws a box or case D, in which rests an, indicator d, the stem e
of which passes down through the lower end of the box, and has secured to it
a float that rests upon the top of the mercury within the cistern. As the
inercury rises or falls the indicator will correspondingly rise or fall and exhibit
to the eye the height of the mercury. In order to raise or lower. the mercury
to the zero point (at which it should stand) the bottom g of the cistern is
made of leather, rubber, or other equivalent flexible material, which is adjusted
up or down by any convenient means, that represented being a screw h.. It
is obvious that as the mercury rises higher or lower in the tube C by reason
of variations in the atmosphere, that the means above described will enable
that in the cistern to be raised or lowered exactly to the zero point.. In the
tube C rests a buoy J, Figure 2, also a simple. tube air-tight, and which floats
in the mercury as indicated. To the lower end of the buoy is jointed a rod i,
preferably made of steel, which passes down loosely through a nut k at the
end of the tube C, and screws or otherwise attaches to a cross bar 1. This
cross bar unites at its extremities with rods m, m, extending upwards through
the cover of the cistern, and attached at their upper ends to a simple ring n,
which they support. The ring is provided with a number of arms 0, 0, 0,
which support air or gas tight chambers E, E, which from their office I
denominate "balloons."
In the Drawings these balloons are represented as of cylindrical form and
of considerable length, being supported at their upper ends by arms p, p,
extending downward from an air-tight globe or crown chamber F, whose
office is similar. The tops of the balloons are shown as formed into globes
9, 9, which form part of them. Thus it will be perceived that the whole
weight of the balloons and the crown chamber is supported by the buoy J
within the mercury tube, and consequently will rise and fall with it. The
buoy and the balloons and crown chamber have a close and intimate action
upon each other. As the mercury rises or falls by reason of atmospheric
changes, the buoy will rise or fall, and consequently also the balloons and
crown chamber. The balloons and crown chamber are made very thin and
light, and are filled preferably with air, though, if desired, they may be filled
with gas. Thus they are nearly balanced or suspended in the outer atmo-
sphere, and any perceptible change in the density or rarefaction of the latter
will have a tendency to correspondingly raise or fall the air chambers, which are
exceeding sensitive owing to the unchangeability of the air within them. The
advantage secured is that the sensitiveness of the air chambers has a tendency

page_text: to overcome the inertia of the mercury within the tube, 'and make it much
more sensitive than would otherwise be the case, and it is upon this fact that
the great value of my device rests. The employment of the air chambers
overcomes in a great degree the friction and the sluggishness in the action of
the mercury. This same effect will be produced if the air chambers are
made of a different form, situated in a different position, or even made in a
single body.
I do not confine myself to any form, position, or number; for instance,
the chambers or chamber might be suspended either beneath or above the
mercurial column, provided the proper connection were made with the buoy
within the tube, and still the same effect would be produced. I prefer the
arrangement described simply because it is convenient aud gives a pleasing
ornamental effect. For this purpose, and also to protect the parts from dirt;
I also prefer to employ a glass cover I as shown. The nut at the lower
end of the tube C, by having a contracted. passage for the rod i through, has
a tendency to give a greater steadiness to the action of the mercurial column in
the tube. To the top of the mercury tube C is secured a cap K; Figures 2
and 3, from which extend arms for the purpose of attaching the dial M, as
shown most clearly in Figure 5. From the top of the cap also projects a
spindler, over which slides the bearing of the framework of the air
chambers as the latter rise and fall. This bearing is preferably provided with
several small friction rollers t, t, Figures 2 and 5, which lessen the friction
and allow the bearing to play up and down with the greatest ease and
freedom. The crown chamber is provided with a socket u to slide over the
spindle when the air chambers fall. To an arm of the ring n at the bottom
is secured a rod N, which extends upward, and has its upper end formed into
an oblong loop or yoke v, Figures 2, 3, and 5, that encircles a grooved
pulley o, the axis x of which at the inner end rests in a jewelled bearing,
while its outer end sustains the large hand P that moves around the dial.
Longitudinally across this loop or yoke is strung a cord or chain w, which is
wound once or more around the pulley, and has at one end a small spring j
to draw it constantly taut. The upper end of the rod N is sustained by a
connection Qattaching to the base of the crown chamber. The rod N is
provided with a projecting arm y, which passes outward through a vertical
slot.z in the dial, and has attached to it a cross hand R. The dial has
marked upon its face two scales, one up and down on the margin of the slot,
and the other circular around the edge. The former is to indicate whole
inches, and the latter subdivisions. As the rod N moves up or down with
the air chambers, the cross hand R indicates the inches upon the vertical

page_text: scale of the dial. The same up-and-down movement will also give motion to
the pulley O by reason of the cord or chain w, and consequently the hand P
will pass around the circular scale and indicate the subdivisions of inches.
The instrument I have produced is extremely sensitive, and will foretell
with great accuracy the approach of storms and any variations in the atmo-
sphere. The air chambers act similarly to a cloud in the atmosphere, being
carried up or down in proportion to the density of the medium that supports
them. The object of this balloon appendage to the mercurial column is to
take advantage of the small premonitory atmospheric pulsations always pres
ceding the more marked fluctuations of the barometer incident to storms.
The hand R is adjustable vertically.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim the improved
instrument for indicating atmospheric changes constructed and acting sub-
stantially as herein-before described, and represented in the accompanying
Drawings.
In witness whereof, I, the said Henry Augustus Clum, have hereunto
set my hand and seal, this Twentieth day of January, One thousand
eight hundred and sixty-six.
HENRY A. CLUM. (L.S.)