IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC BAROMETERS
Year: 1860

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for
the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC
BAROMETERS. A communication from abroad by M. Felix Richard,
of Paris.
-
Scaled the 23rd October 1860, and dated the 14th May 1860.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
14th May 1860.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lanc,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC
BAROMETERS," to be as follows:-
This Invention of improvements in the construction of metallic barometers
relates to certain improvements upon the instrument known as Bourdon's
barometer, and has for its object to construct a tube of great sensibility, and
which will be affected by very slight alterations in pressure.
The Invention has also for its object to increase the action or motion of the
tube, so as to render it less difficult to amplify or increase the movements of

page_text: the index. The Invention consists in adapting a steel spring to the flattened
tube of the Bourdon barometer. This spring may be adapted or fixed to the
tube itself by enclosing it within the tube, or by securing it to the outside so
as to make the spring and tube act in combination, or a convolute or coiled
spring may be adapted to the axle of the index arm, or some other part of
the instrument, so that it may act in combination with the tube.
Another part of the Invention consists in various novel modes of trans-
mitting motion from the flattened tube and the steel springs to the index arm
of the instrument. To this end the tube is held at or near the middle, and
the two extremities are connected with or made to act on an axle by means of
chains, racks, or other suitable gearing, so as to transmit thereto the motion
of the ends of the tube. This motion is transmitted by means of a sector rack
and pinion to the index arm of the instrument. Sometimes it is proposed to
employ two flattened tubes, each fixed by one end, instead of using only one
tube fixed at or near the middle. The opposite ends of these two tubes are
caused by means of chains or gearing to act on an intermediate axle, and, by
the intervention of a sector rack, also on the axle of the index arm, or the
free ends of the flattened tubes may be made to act directly on the sector
which works the axle of the index.arm.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office
on the 14th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of May, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, administrators, and assigns, or such others
as 1, the said William Edward Newton, 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 of Great

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF METALLIC BAROMETERS," being a commu-
nication from M. Felix Richard, of Paris, upon the condition (amongst others)
that I, the said William Edward Newton, by an instrument in writing under
my hand and seal, 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 William Edward Newton, do hereby
declare the nature of the 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 Drawing hereunto annexed,
and to the letters and figures marked thercon (that is to say):-
as
This Invention of "Improvements in the Construction of Metallic Baro-
meters" relates to certain improvements upon the instrument known
Bourdon's barometer, the object being to augment considerably the precision
of such instruments, which have hitherto only been adapted for household
purposes (that is to say), to shew pretty accurately the variations of the atmo-
sphere in apartments. Before entering into a detailed statement of the present
improvements, by which these instruments may be considered to be converted
into barometers of extreme sensibility, it may be as well to give some account
of their primitive construction, and of the circumstances which have led to the
present improvements.
Being the assignee of that portion of M. Bourdon's Patent relating to the
application to barometers of the general principle therein set forth, tho
Inventor of the present improvements sought the mode of construction which
should give to those instruments the greatest possible precision and sensibility.
The first satisfactory results which he obtained produced the metallic baro-
meter, now so well known, and which gives with great exactitude ordinary
atmospheric variations, which, as is well known, vary according to latitude, and
which in Europe rarely exceed from an inch to an inch and a half for a column
of mercury, the normal height of which, taken at mean sea level, is about
seven hundred and sixty millimetres (about two feet six inches). It is well
known that this metallic barometer consists of a brass tube, the transverse
section of which is formed of two arcs of a circle, whilst its general form is a
circular ring, which is severed at a portion of its circumference; a vacuum
being established inside this tube, which is perfectly air-tight, variations in the

page_text: surrounding atmosphere will act upon it, and modify its form and general
curve; this latter peculiarity is taken advantage of to ascertain the degree of
atmospheric pressure by means of suitable mechanism, which shall transmit
these variations of form to an index or pointer. By this simple and limited
application the instrument fulfilled the required object in the most complete
manner; but if it were required to extend its application to scientific observa-
tions for meteorological purposes, for navigation, for ascertaining elevations,
or in fact for any purposes where either great or very small degrees of pressure
are required to be ascertained, the following difficulties of various kinds have
to be overcome.
First, if a tube of very thin brass be constructed of such substance as to
possess the required sensibility, the alteration in its form is such that on a
variation of pressure of one atmosphere taking place the curved tube instead
of being of a semicircular form becomes nearly a perfect circle, and the
extremities are brought too near each other to permit of their being connected
with the mechanism, which serves to transmit their movements to the index;
in fact when the curved tube is rendered sufficiently sensitive by diminishing
the thickness of the material its flexibility is too great.
Secondly, on the other hand such flexibility cannot be regular with a metal
so malleable as brass, whatever may be the means employed for hardening or
tempering it, and consequently its elasticity cannot be perfect, that is to say, it
will not resume exactly the position it occupied before the pressure was exerted
upon it.
Thirdly, supposing the above difficulties, however real they may be, to be over-
come, there still remains the difficulty of arranging a mechanism capable of
transmitting (without error, and without too great an absorption of power for
passive resistance) movements, which may be extremely slight, and which
must be greatly amplified in order to render them easily susceptible.
The Inventor has therefore endeavoured, in order to overcome these
difficulties, to construct a very sensitive tube which is capable of being affected
by very slight variations of pressure, and which shall comprise a great range of
pressure in order to simplify the amplification of its movements, and which
shall be of such perfect elasticity, that it shall always shew the slightest degree
of pressure to which it is subjected.
As therefore the principal difficulty seems to consist in the imperfect elasti-
city of the brass of which the tube is made, steel which is the most elastic metal
known should have been employed, but the construction of these tubes which
is sufficiently diflicult in brass is almost impossible in steel.
It was therefore

page_text: necessary to seek a remedy for this, and the Inventor of the present improve-
ments has found one, which while it is not difficult of application gives exactly
the same result as would be obtained if these tubes were made of tempered
steel. To this end the Inventor simply applies to the ordinary brass tube a
steel spring, which yields to the movements of the tube, and yet causes this
latter to maintain its normal curved form, the metal retaining its perfect elasti-
city. The tube thus becomes the receiver of a motive force, which is divided
into two parts, that is to say, one part for its own bending and the other for
that of the spring. As it is upon the brass tube that the pressure acts,
straightening it more or less, it may be rendered as sensitive as may be deemed
necessary by diminishing its thickness, as the spring will always keep it
at the same rigidity as regards its curved form, which rigidity will be in
some sort independent of the reduction in the thickness of the metal. This
principle being laid down, it is evident that there exist different methods of
arranging the spring, which the Inventor of the present improvement has
devised, and which will be herein-after described, although he prefers one of
them which seems to effect the desired end in the most perfect manner. Thus
after having employed spiral convolute or helically coiled springs, the Inventor
conceived the idea of employing flat ones, which were at first disposed around
the tube inside and outside, and finally were placed in the interior of the
tube; it is this latter arrangement which is found to be the most effective,
and which the Inventor therefore prefers.
With regard to the different methods of transmitting the movements of the
tube to the index, although less important than the principle of the Invention,
I will hereaftor describe those arrangements which the Inventor proposes to
employ; although of course those will be preferred which indicate with the
greatest precision.
The improved barometer is represented in various views in the accompanying
Drawing, in which the same letters indicate similar parts.
The first method of applying the spring is represented at Figures 1 and 2, which
represent in front and side views the mechanism of a barometer with the
spring applied to the motive tube A according to the first method. This tube
is fixed at the middle of its length to the standard or support B, and its lower
extremities are free to move, and are connected with the mechanism F, which
transmits their movements to the pointer or index C. This mechanism is
composed of two chains D, which are attached to the two moveable ends of the
tube A, and pass round two pullies E to another pulley F, but at opposite
sides of its diameter. The axle a of this pulley also carries a toothed sector

page_text: G, which takes into the pinion H mounted on the axle 6 of the index or
pointer C. A barrel 1 carries the important spring above referred to.
This barrel is connected by a chain J, with a pulley K, mounted upon the
axle a, which also carries the large sector G and the pulley F, to which are
attached the chains D. The tension of the barrel spring I being regulated
in the direction which corresponds to the winding of the chains D on to the
pulley F, it is clear that this tension will be constantly exerted to separate
the open ends of the tube A; but these ends possess the property of moving
nearer to or further from each other according to the degree of exterior
pressure to which the tube A may be submitted. Consequently if the arms
have a tendency to approach each other they must overcome the action of the
spring I, which is an additional resistance to the bending of the tube A.
If, on the contrary, they should have a tendency to open or separate, the
action of the spring I will aid them in this, as they then all act in the same
direction. The spring of the barrel I is therefore a resistance which must
be overcomo by the flexion of the tube A, and which produces the same effect
as if that tube itself offered a greater resistance to its flexion.
In conformity with what has been above stated, the tube A produces great
action by the separation or movement of its open ends, which evidently
approach each other in a less degree for an equal amount of pressure than
if the spring of the barrel I did not exist, as before arriving at its utmost
point of compression the tube must overcome the resistance of the spring.
The elasticity of this spring alone will ensure the exact return of the tube to
all the different positions for the same corresponding pressures.
Fig. 3 represents a somewhat similar arrangement of apparatus, with this
difference only, namely, that instead of the first portion of the chains D
(Fig. 1), rigid pieces D'are employed, by the use of which the pullies E may
be dispensed with.
The arrangement shewn in Fig. 4 consists of two curved tubes acting upon
a single needle or pointer, having also the barrel spring I. These tubes are
both fixed upon one common framing B by one of their extremities, the other
end being free and in communication with the indicating apparatus by means
of chains D. A slight difference, however, exists from the preceding
apparatus in the manner of connecting the mutual actions of the tubes A, and
of the spring of the barrel I. Instead of the chain J and pulley K of
Figures 1 and 2, the axis of the barrel I is rigidly connected with a toothed
sector J', which takes into a pinion mounted upon the axis a of the pulley F.
The operation of the parts is the same in both cases.

page_text: Second method of applying the spring. This is intended as a substitute for the
barrel spring I, above described, its office being to modify the elastic properties
of the curved brass tube A. The barrel or spiral springs I do not possess so
strong and regular a degree of elasticity as a simple flat spring with a single
curve; these latter also act more quickly and perfectly. In the first arrange-"
ments described the barrel springs I are, however, employed, but for a different
purpose; they serve simply to give tension to the chains when these latter aro
employed for transmitting the movements of the tube, which is provided with
its modifying spring.
Fig. 5 in the accompanying Drawing represents this first application of the
flat spring which is employed in place of the convolute spring I, Figures 1
and 2, as above mentioned. I is the flat spring, which is made of steel, and
is of the same length as the tube; this spring was at first adapted to tho
outside of the curve of the tube, as indicated by the blue lines at Fig. 5,
afterwards within the curve of the tube, as indicated by the red lines in the
same Figure, and ultimately the plan adopted was to place it in the interior of
the curved tube, as seen at I in the same Figure, in which the brass tube A
is shewn partly in section. By this arrangement the action of the tube A
may be regarded as if the spring I did not exist; the elasticity of the spring is
also much more perfect by reason of its great developement compared with
the flexion which it has to undergo, and which is very little for a steel spring
of such length, and of a quality to enable it to serve as a clock spring.
On the other hand, the spring thus enclosed in the tube, where a vacuum
exists, is in a neutral medium, and protected from all deterioration.
As regards the mechanism for transmitting the movement of the tube to the
index hand or pointer, it may be observed that it consists simply of two
chains D, a pulley F, the large sector G, and the pinion H, on the axis of the
index or pointer C. As, however, the employment of chains necessitates also
an apparatus for giving them tension, in order to indicate when the ends of
the tube approach each other, the Inventor proposes, in order to effect this
object, to employ a light convolute or coiled spring, mounted upon the arbor of
the sector G; or this arrangement may be replaced with advantage by those
which will be now described.
Figures 6 and 7 are detached views of methods of mounting and working
the shaft a, on which is set the pulloy F for connecting the chains with the
toothed sector G.
In the arrangement shewn at Fig. 6 the tension of the chains D is effected
by means of a barrel spring c', mounted upon the shaft a, and furnished with
.

page_text: its accessories, such as a toothed wheel, and ratchet, and click. But it
happens under these circumstances that the sector describing angles of con-
siderable extent, the barrel spring is subject to unequal tension, and conse-
quently communicates unequal tension to the chains, which interferes with the
working of the instrument; it may, therefore, be preferable to employ the
arrangement represented at Fig. 7, which represents the spring barrel c' as
mounted upon an intermediate arbor a', and acts upon the main arbor a
through a toothed wheel gearing into a pinion c³, the result of which is that
the angles of torsion of the barrel being always weak compared with those
described by the sector, the variation of force is also almost inappreciable,
and cannot interfere with the free working of the tube A.
In the arrangement shewn at Fig. 8 the auxiliary spring for giving tension
to the chains D is entirely done away with; but for that purpose the motivo
force of the tube is lessened by one-half, although this tube is provided in its
interior with the main spring I (see Fig. 5), which is the most important part
of the present improvements. For this purpose, the tube A being fixed as
before upon the framing B by the middle of its length, its extremities are
connected by means of a single chain D, which leads directly from one of
these ends, passes round the pulley F, and thence to the other extremity of
the tube, after first passing over a teusion pulley E. The result of this
arrangement is that on the tube opening by reason of a diminution of
atmospheric pressure, the chain attached to the tube acts directly upon the
indicating apparatus; on the contrary action taking place (that is to say) on
the extremities of the tube approaching each other, the opposite end, in
connection with the pulley E, will act upon the indicator, and bring the chain
to tension.
In Fig. 9 an arrangement is shown in which two tubes A and A' are
employed in combination. In this instance the tubes are both fastened to the
frame at one of their ends (say, the left one, as shown in the Drawing, but
either right or left will answer the purpose), and the free ends are connected
by the chain D, which passes round the pulley F. In this instance, as before,
only half the motive force acts at one time; for, on the tubes opening, the
tube A will give tension to the chain; but on their closing the tube A will act
upon the indicator.
Figures 10 and 11 represent an arrangement in which the whole motive
force of the tube is utilized at once in both directions of its movement, by the
employment of a connecting rod, which acts upon a double system of sectors
and their pinions. The tube A is fixed upon the framing B at one of its

page_text: extremities, the other one being free and brought into connection with the
indicating apparatus, by means of a connecting rod D. This connecting rod
or link is hinged to a sector G', which is free to move on the arbor 6 of the
index or pointer, and takes into a pinion F upon the axle a of the sector G,
which acts upon the pinion E, mounted on the index or pointer shaft b. By
this arrangement the variations in the movements of the free end of the tube A
will be communicated by the connecting rod D to the sector G¹, which will
actuate the arbor a by means of the pinion F, and will consequently act upon
the sector G, which will actuate the index or pointer shaft by means of the
pinion H. By this means the whole force of the tube will be brought into
action, and all chains or tension springs are dispensed with.
In Fig. 12 another arrangement is shewn, the curved tube being fixed as
before, at its upper end or middle of its length. In this instance the two freo
ends are connected to two racks D, which severally take into the pinion F,
mounted upon the arbor of the sector G. These racks are hinged to tho
open ends of the tube, and are held in contact with the pinion F by means
of springs a.
I will now proceed to describe the arrangements which the Inventor
considers at present to be the best for carrying out his Invention.
From the necessity of simplifying the apparatus for transmitting the move-
ments of the tube to the indicator as accurately as possible under variations of
atmospheric pressure, the Inventor has been led to enquire the manner in
which the pressure is exerted upon the tube, (that is to say,) the course
followed by the open ends of the tube, and it has been shewn by experience
that the free ends of the tube describe in yielding to the pressure an arc of a
circle, the centre of which is situate within the curve of the tube, supposing
this latter to be fixed to the framing at one of its extremities, and outside that
curve, if the tube be fixed at the middle and both its ends be free. By
observing these movements the most correct and simple means of transmitting
them to the indicator is arrived at; for on taking the centre of this movement
to fix the toothed sector which governs the indicator, this sector will, without
intermediate chains or connecting rods or links, drive the pinion mounted
on the arbor of the needle or indicator, or the needle itself may be driven
directly.
In order to render these general principles clear, some few examples of their
application will now be described.
In Fig. 13 an arrangement is shown in which, while the principle of the motion
of the ends of the tube A are taken advantage of, the use of chains is resorted

page_text: to, but under favorable conditions. The tube A is fixed at the middle of its
length, and its free extremities are connected to an endless chain D, which
passes round two pullies E, one of which is acted upon by a spring a, acting
against the bracket on which it is mounted for the purpose simply of giving
to the chain the requisite initial tension. It is evident that on the ends of the
tube moving towards or from each other, the inversion of the points of attach-
ment will very well maintain the tension of the chain D. In order, however,
to conform to the principle of the developement of the ends of the tube, it has
been found necessary to arrange this chain in such a manner that the points
where the ends or branches of the tube are connected shall be chords or tan-
gents of the arcs which these latter describe.
The movements of the tube are transmitted to the index or pointer by means
of the sector G mounted upon the axle of one of the pullies E, and taking
into the pinion I mounted on the arbor of the pointer C. As an example of
what may also be applied to any other arrangement, an additional index J is
here shewn, the axle of which is provided with a pinion I, driven by a wheel F,
which turns with the principal index or pointer C. This second needle J
evidently acts as a multiplyer of the movements of small extent, and following
the same principle, an instrument may thus be provided with several similar
multiplyers, (that is to say,) several pointers and dials corresponding to unities
of decreasing extent.
Fig. 14 represents a barometer composed of a single tube A fixed at its
middle, and having its ends free to move. When the ends of the tube are
moved under variable exterior pressure, they will describe the ares of circles
a, b, and c, d, the respective centres of which are e and f, outside the tube.
On these centres are mounted two large toothed sectors G and G', which are
respectively connected with the ends of the corresponding branches of the
tube, and which take respectively into pinions H and H'. These pinions aro
mounted upon shafts, which carry the wheels I and 1', gearing into cach
other. By this arrangement the flexion of the right hand end of the tube will
act upon its sector, and through it upon the pinion H, and this with great
regularity, as the curve of the sector is concentric with the movement of the
arm of the tube. This is the case with both ends of the tube, and the two
pinions Hand H' rotating in contrary directions, and the wheels I and I'
taking into each other. These actions will be added to one another, and will
impart the whole force of the action of the tube A to the indicating apparatus.
In order to transmit these movements to the index C, a sector G² may be
mounted on the shaft of either of the pinions I or II', which will act upon

page_text: the pinion H mounted upon the index or pointer shaft. By this arrangement
any organ of transmission which is capable of yielding is dispensed with, and
loss of time in the gearing is avoided.
I would also call attention to another important advantage of this mode of
transmission, which is that an instrument so constructed may be placed in any
position without fear that its weight shall accidentally bend the sides of the
tube and destroy the accuracy of the indications. If, for instance, the instru-
ment be placed on one side, the branches of the tube being acted upon by its
weight will have a tendency to be lowered on the same side, (that is to say,)
one will close and the other open, but in order to produce this effect it would
be necessary for the wheels I and 1' to turn in the same direction, which is
impossible, as they take directly into one another; consequently the two actions
will neutralize each other, and the branches of the tube will remain stationary.
Suppose the instrument to be placed vertically it will be seen that each branch
being attached to the sector rack, and this latter at a fixed point, it cannot
yield to the action of the weight.
Fig. 15 represents another arrangement in which the tube is fixed at one of
its extremities, the other acting direct upon the index or pointer D, which has
for its centre that of the curve generated by the end of the tube in bending,
the centre being in this case inside the curve of the tube, as above mentioned.
The pointer will by this means furnish direct indications upon a dial C, the
divisions of which may be increased in size by any convenient arrangement,
and a vernier may be adapted thereto.
Fig. 16 represents another arrangement in which two tubes are employed
together, with a mode of transmitting the motion based upon the preceding
observations. Each of the tubes A and A' is fixed at one of its ends, the
other end of both tubes being free. The other end of the tube A¹ is connected
with a sector rack G, of which there are two, both gearing into a common
pinion H, upon the arbor of which is mounted the pointer C. It is remarkable
that this arrangement possesses the same property as one of the preceding
ones with regard to the equilibrium established by compensation, and which
destroys the abnormal actions under the influence of the weight.
These improved barometers will, as above stated, allow of altitudes being
measured with a precision and facility hitherto unknown. But not only can
accurate and minute observations be made with them, but any automatic
registering apparatus may be applied to them. For instance, an endless
band of paper may be applied, and motion communicated to it by clockwork,
which shall receive the indications of the barometer by means of any suitable
marking apparatus.

page_text: I would here observe that as the power of the barometer depends upon its
dimensions as regards the excess of pressure to which it is subjected, and the
extent of its indications, the motive tube may be of such dimensions as may
be thought desirable, and increase either its general diameter of curve or its
breadth in transverse section, according to circumstances.
In conclusion, I will describe the means which the Inventor employs in
order to mount the spring I in the brass tube, this being the flat spring above
described, and which forms the principal feature of the present Invention.
Fig. 17 represents a tube detached, a portion of its ends being cut away to
shew the mode of applying the spring I; Fig. 18 is a transverse section of the
tube; Fig. 19 shews one extremity of the tube with the spring attached
thereto in section, taken through the tube in the direction of its breadth;
Fig. 20 is another section of the same taken at right angles to the preceding
Figure.
The spring I is attached to the tube A by fixing it between two jaws or
holders a, made of brass and shaped to fit the transverse section of the tube.
These brass holders are fixed upon a plate b, which abuts against the end of
the tube; the spring I being first fastened to one of the holders by means of
two small rivets c, is introduced into the tube until the holders are set therein
or fit in the bottom. The spring will then bend round and take the form of
the tube, and its other end may be attached to its holders and fixed to the
other and open end of the tube A. In performing this latter operation the
spring will have been forced back a little, its length being so calculated that
on being thus introduced into the interior of the tube it will occupy exactly
the middle thereof, according to its transverse section. The holders a being in
their place are soldered in, and the tube will be perfectly closed. It will be
observed on referring to Fig. 20 that the tail of one of the holders is a little
longer that the other, and on referring to Fig. 17 it will also be seen that this
peculiarity only exists at one extremity of the tube. The object of this is
to support the tube and give its extremity the initial curve required to corre-
spond to the contour of the tube.
Having now described the Invention of "Improvements in the Construction
of Metallic Barometers," and having explained the manner of carrying the
same into effect, as communicated to me by my foreign correspondent, I would
observe that I do not mean or intend to confine myself rigidly to the precise
arrangement or construction of parts herein shewn and described, as they may
doubtless be varied without departing from the nature and object of the
Invention; but what I consider to be new, and therefore wish to claim as the
Invention secured to me by Letters Patent as aforesaid, is the application or

page_text: use of a steel spring or springs in combination with the flattened tube or tubes
of a Bourdon's metallic barometer, as above set forth, whereby the elasticity of
the tube or tubes is modified or regulated, so that the same elastic property
may be given to the tube or tubes as if they were made of steel; I claim also
the mode or modes herein set forth of transmitting the motion of the flattened
tubes (caused by the changes of the atmospheric pressure) to the indicating
apparatus, and the mode or modes of arranging this latter.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Fourteenth day of November, in the year of
our Lord One thousand eight hundred and sixty.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)