IMPROVEMENTS IN ORDNANCE
Year: 1874

page_text: LETTERS PATENT to Emile Schultz, of Paris, in the Department of the
Seine, in the Republic of France, Captain of Artillery, for the
Invention of " IMPROVEMENTS IN ORDNANCE."
Sealed the 16th October 1874, and dated the 21st April 1874.
PROVISIONAL SPECIFICATION left by the said Emile Schultz at the
Office of the Commissioners of Patents, with his Petition, on the
21st April 1874.
I, EMILE SCHULTZ, of Paris, in the Department of the Scine, in the
Republic of France, Captain of Artillery, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN ORDNANCE," to be as follows:-
Principle of my Invention.-A cannon is liable to rupture or bursting
from two causes, one which acts following the radii of the cylinder, and
tends to open the piece following a generating line, and another which
acts parallelly to the axis, and tends to produce a separation or parting
from the breech.
My new method of construction consists in dividing these two

page_text: it is this sum which gives the measure of what I will term the unvarying
resistance of the cannon, a resistance which may be far from the point
of rupture. The second principle consists in arranging the envelope
intended to compress the central tube in such a manner that cach of
its particles takes an equal part in the total resistance, and works under
a constant tension exactly ascertained.
Use of Elastic Metal Wire to Compress the Central Tube.-To attain
this result I envelop the central tube with a certain number of layers of
an elastic metal wire wound under a fixed tension produced by a weight
suspended to the wire during the winding or coiling. The tensions of all
the layers accumulated upon the central tube, and their sum in relation
to the unity of surface, forms the unvarying resistance of the piece. So
long as the inside pressure of the gasses does not reach this total the
borc remains invariable, and the wires will have to undergo no other
tension than that of the weight which has served for the winding. In
order therefore that all the layers may take an equal part in the resistance
it is only necessary to coil them all under a constant weight. If this
weight is equal to the limit of the elasticity of the wire the maximum of
possible resistance of the metal of which it is made will have been
obtained, and the further important result be realized that this
resistance will be proportionate to the weight of wire used, and indepen-
dent of the quality of the central tube, provided this latter can resist tho

page_text: Mode of Winding or Coiling.-In order that the tensions obtained by
the coiling may endure indefinitely it is requisite, firstly, that the fas-
tenings of the wire be absolutely secure; secondly, that its elasticity
may not in time become deteriorated. This latter condition depends
simply upon the quality of wire used and the weight which it is made to
bear. The use of hardened iron wire is therefore possible, and steel wire
would be preferable, but I specially mention the wire used for pianoforte
strings as fulfilling in the highest degree every requirement. The
coiling under constant tension is effected in the simplest manner;
the wire is first wound upon a roller of a diameter about equal to that
of the piece and of the same length. The wire starting from the roller
and fixed to the piece carries a pulley to which is suspended a weight
double the tension which it is desired to obtain. The piece and the
roller are slowly turned in the proper direction, and the wire given off
by the roller coils on B (Fig. 4) under the constant tension desired.
These movements may be obtained by hand by the aid of cranks or by
mechanical means; in fact it would be sufficient to unite the piece and
the roller by two toothed wheels, the number of teeth of which would
be in inverse proportion to the lengths of wire given off, in order that
the effort to be made shall be nil with the exception of that required to
overcome the passive resistances. Each layer is composed of a single
wire or of several wires coiled in contiguous spirals or helices. Each
wire is fixed at its two ends, and has its fastenings independent of those
of the other wires. In this manner the spires of one row running in the
same direction as those of the preceding lodge exactly in their interstices,
touching them in their entire length, following the lines of contact. The
faces C, which limit the space reserved for the wires, are turned in helices
of of the coiling pitch, so that the extreme end spires find a bearing
there in their entire circumference. The number of layers may vary
from the mouth to the breech, so that the resistance which is propor-
tionate to this number may decrease from the breech to the mouth of
the picce like the pressures which they have to resist. The spires of the
first layer are tightly squeezed against each other during the coiling; the
others need no special attention, cach wire necessarily following the
pitch of the preceding layer lodges itself in the spaces between its

page_text: little space; it must be absolutely secure; finally, the fastening must
take place while the wire is supporting the coiling weight, and without
any variation of its tension.
First Method of Fastening (see Fig. 5).-A first means of attaining
this object consists in squeezing several wires between two pieces with
undulating surfaces intended to produce gentle curves in the wires. The
squeezing of these pieces is obtained by screws or by wedges.
Second Method of Fastening (see Figs. 6, 7, and 8).-The means to
which I give preference consists in inserting the wire into a slit a of
rectangular section made in a picce of tempered steel b. The width of
this slit is slightly less than the diameter of the wire. The result is that
the wire being sunk into this slit is cut against the sharp edges of the
steel, two small segments are removed, and the wire forms a real riveting
a (Fig. 8). The pieces of steel forming fastening are set transversely to a
channel D, where meet the ends of the wires of all the rows. The wire
which it is desired to fix comes on to the edges of the slit while still
remaining under the tension of the weight which it supports. A blow
from a hammer is sufficient to drive it into the slit, and the fastening is
thus completed without any variation of the tension.
Variable Resistance at Different Points in the Length of the Piece.―
The interior pressures of the gasses decrease with sufficient rapidity
from the breech to the mouth of the piece, that it is in most cases only
requisite to envelope the reinforce with wire; the chase, then solely
formed of the metal of the central tube being supposed to have of itself
sufficient resistance. This is the case assumed at Fig. 1 of the Drawing..
It may nevertheless be desirable to vary the resistance of the tube from
the breech to the mouth; for example, to employ thirty layers of wire at
the breech in the first third part of its length, twenty on the second, and
ten upon the last at the chase. The fastening channel of the breech
should contain the fastening pieces intended to fix the wires of the thirty
layers. The first ten should extend without interruption the entire
length from the breech to the mouth, where they are fixed. The suc-:
ceeding ten will extend two-thirds the length. The last ten over only
one third. Figures 10 and 11 show this arrangement.
Method of Fastening the Intermediate Layers.-To fix the ends of
these intermediate lavers two means may be used.

page_text: 1°. At each of the points where a layer is to end there is made in the
metal of the central tube a channel G forming a projection equal to that
of the layers which reach this point, the bottom of this channel is the
extension of the general coiling surface which may be cylindrical or
conical. The two faces of the channel formed interiorly and exteriorly
spirally to the coiling pitch are cut by two slits which permit the
entrance and exit of the wires (see Fig. 10). The lower part of the
channel is occupied by the layers which only pass through it to be fixed
further on, the upper part carries the fastening pieces of the wires which
are to end at this point. Thus, in the example assumed, the first
channel starting from the mouth would have a projection equal to that
of thirty layers, it would give passage to the ten first extending over the
entire length and intended to be fixed at the mouth, and would serve to
fix the succeeding ten, which envelope the two first thirds. The second
channel would have a projection equal to that of thirty layers; it would
give passage to the first twenty and carry the fastenings of the last ten.
2º. The second means (Fig. 11) consists in, firstly, coiling the first ten
layers without break from the breech to the mouth where they are fixed.
On the outer surface of the tenth layer and at the point fixed upon for
the stoppage of the following is inserted a ring H carrying the fastenings
of the ten succeeding layers. This ring is put on hot with a pressure
sufficient to secure it from displacement by the traction of the wires of
which it is the fastening.
Protection of the Wires.-To protect the layers of wires they are
covered with a tube of bronze or sheet copper set on hot so as to
penetrate into the interstices of the wires by its contraction and preserve
them from rust and against exterior blows or shocks. This precaution
is needless for the layers of the reinforce which are sufficiently protected
by the breech jacket or casing. The cannon represented, Fig. 1, being
enveloped only at the reinforce has no copper casing.
The Casing or Jacket Principle.-I have previously said that my
method consists in separating the two causes of rupture and to resist them
separately by two distinct parts. The tube which I have just described
is intended to resist rupture in a generating line. Moreover the breech
could not with impunity be fixed to the central tube which will
generally be very thin. There remains therefore to describe the piece
intended to resist separation or parting at the breech. This piece is a

page_text: casing or jacket M (Fig. 1) enveloping the tube and carrying at tho
same time the breech and the fastening for securing the piece upon its
carriage. The tube being invariable this casing or jacket will have to
experience no expansion following the radius, and will only have to
resist the longitudinal strain necessary to overcome the inertia which
the piece opposes to the recoil movement. I thus avoid the main cause
of parting at the breech which mostly arises from the rending of tho
metal under the two rectangular actions which are produced at tho
bottom of the bore in pieces loaded from the mouth, and at the bearing
surface of the brecoh-closing piece in breech-loading guns.
Construction and Fitting of the Casing or Jacket.-The jacket or
casing may be of any kind of metal. It will generally be found
preferable to make it of wrought iron, in which case, thanks to its
slight thickness, it may be made hollow by means of a wrought-iron
plate rolled into a cylinder, and soldered, following a generating line.
This casing or jacket is inserted over the mouth of the picce, and is
arrested by a projection abutting against the front m of the part to
which the wires of the reinforce are fastened. If the surface of the tube
is conical this projection will be needless. The jacket is fixed at the
back by a screw N, which finds a bearing against the face of the piece
behind the tube A. This screw will be solid if the cannon is intended
to be loaded by the mouth, and hollow if to be loaded by the breech.
The inner part then serving as fulcrum to the breech-closing arrange-
ment, which in the Drawing is supposed to be a breech screw with
flutes breaking the threads. The jacket will usually be put on hot, and
the screw tightened close up before the cooling. This operation is not
intended to produce a pressure on the tube, for the metal of the jacket
in shrinking becomes incrusted in the interstices of the wires; its object
is to increase the adhesion of the jacket or casing by spreading its
bearing over a large surface to completely protect the wire by its
incrustation in the hollows, and finally and above all to produce in a
longitudinal direction upon the jacket an initial tension analogous to
that which the wire produces upon the central tube. The effect of this
tension is to withdraw the jacket from the violent shock of the discharge
by creating beforehand a longitudinal traction capable of partly
equilibrating it. If the jacket is put on cold the initial tension will be
obtained by the rapid tightening up of its back screw by the aid of a
large lever arm, and if necessary by windlasses. If, on the other hand,

page_text: the breech closing is so arranged as to press strongly against its seat, or
against its screw threads if a screw be used, it will be certain that the
jacket will experience no shock, and thus realise the desired condition of
having to resist only longitudinal tractions. In the case of breech
screws with broken threads, otherwise "fluted screws, I give a special
and novel arrangement. It consists in forming the section of the screw
threads following a helix instead of making it following a generating
line. In this manner the threads preserved may occupy the entire cir-
oumference of the screw, and spread the pressure equally over the entire
section of the jacket instead of localising it, as in the second case, upon
three parts which bear a greater strain.
Method of Fixing the Piece upon its Carraige.-The preservation of
the carriages is very difficult in the case of light pieces firing with heavy
charges, and to obviate this defect it has been proposed to interpose steel
springs between the piece and the carriage. To attain the same end I
use the following method of mounting the piece :-For this purpose a
cylinder O (Figures 1 and 1*) having trunnions P is set in the ordinary
manner on a carriage. The piece may slide freely in this cylinder like a
piston. In the space left between the cylinder and the piece are placed
springs or washers of india-rubber p, p, analogous to those used for the
buffers of railway waggons, and separated by sheet-iron washers r, r,
intended to isolate and centre them. These washers bear against the
rear end P¹ of the cylinder. The cannon has a projecting ring Q, which
bears against the india-rubber washers on the steel springs, and com-
presses them under the effect of the recoil. An india-rubber washer R
is interposed between this ring and the front end of the cylinder to
deaden the return shock of the the piece when it is brought back to its
primitive position by the distension of the compressed washers. The
object of this arrangement is not to lessen the recoil, but to deaden the
shock of the piece against its carriage by transforming it into a con-
tinuous pressure. This arrangement presents another advantage, namely,
that of permitting the pointing to be completed without displacing the
trail. For this purpose it is only necessary to leave a slight play at a
for the lodgment of the piece in the rear end of the cylinder, so that it
may be moved laterally to a slight extent by pivoting round the axis of
the bearing ring Q against the washers. The opening left for the
passage of the piece in the bottom of the cylinder is made following a
straight line horizontally. The piece carrying two flaten parts as S, S

page_text: rests upon the lower horizontal surface of the opening, and the play only
exists laterally. (Figure 1* shows this arrangement.) Two screws or
an eccentric permit moving the piece in this opening, and giving it a
certain inclination on the axis of the cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Emile Schultz in the Great Seal Patent Office on
the 19th October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMILE
SCHULTZ, of Paris, in the Department of the Scine, in the Republic of
France, Captain of Artillery, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Emile Schultz, Her special licence that
I, the said Emile Schultz, my executors, administrators, and assigns, or
such others as I, the said Emile Schultz, 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 Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN ORDNANCE," upon the
condition (amongst others) that I, the said Emile Schultz, my executors
or administrators, by an instrument in writing under my, or their, or.
one of their hands 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 Emile Schultz, 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 :-
Principle of my Invention.-A cannon is liable to rupture or bursting
from two causes, one which acts following the radii of the cylinder, and

page_text: by the invariability of the bore which more completely insures absence
of windage between the projectile and the sides of the bore.
Mode of Winding or Coiling.-In order that the tensions obtained by
the coiling may endure indefinitely it is requisite, firstly, that the
fastenings of the wire be absolutely secure; secondly, that its elasticity
may not in time become deteriorated. This latter condition depends
simply upon the quality of wire used and the weight which it is
made to bear. The use of hardened iron wire is therefore possible, and
steel wire would be preferable, but I specially mention the wire used for
pianoforte strings as fulfilling in the highest degree every requirement.
The coiling under constant tension is effected in the simplest manner.
The wire is first wound upon a roller of a diameter about equal to that
of the piece and of the same length. The wire starting from the roller
and fixed to the piece carries a pulley, to which is suspended a weight
double the tension which it is desired to obtain. The piece and the
roller are slowly turned in the proper direction and the wire given off by
the roller coils on B (Fig. 4) under the constant tension desired. These
movements may be obtained by hand by the aid of cranks or by
mechanical means. In fact it would be sufficient to unite the piece and
the roller by two toothed wheels, the number of teeth of which would
be in inverse proportion to the lengths of wire given off in order that
the effort to be made shall be nil with the exception of that required to
overcome the passive resistances. Each layer is composed of a single
wire or of several wires coiled in contiguous spirals or helices. Each
wire is fixed at its two ends, and has its fastenings independent of those
of the other wires. In this manner the spires of one row running in
the same direction as those of the proceeding lodge exactly in their
interstices, touching them in their entire length, following the lines of
contact. The faces C which limit the space reserved for the wires are
turned in helices of the coiling pitch, so that the extreme end spires find
a bearing there in their entire circumference. The number of layers
may vary from the mouth to the breech, so that the resistance which is
proportionate to this number may decrease from the breech to the mouth
of the piece like the pressures which they have to resist, the spires of
the first layer are tightly squeezed against each other during the coiling;
the others need no special attention, each wire necessarily following the
pitch of the preceding layer lodges itself in the spaces between its
spires

page_text: Method of Fastening the Wires.-The method of fastening must
meet several requirements. It should be sufficiently simple to occupy
but little space; it must be absolutely secure; finally, the fastening
must take place while the wire is supporting the coiling weight and
without any variation of its tension.
First Method of Fastening (see Fig. 5).-A first means of attaining
this object consists in squeezing several wires between two pieces with
corrugated surfaces intended to produce gentle curves in the wires. The
squeezing of these pieces is obtained by screws or by wedges.
The result is
Second Method of Fastening (see Figs. 6, 7, and 8).-The means to
which I give preference consists in inserting the wire into a slit a of
rectangular section made in a piece of tempered steel b. The width of
this slit is slightly less than the diameter of the wire.
that the wire being sunk into this slit is cut against the sharp edges of
the steel, two small segments are removed, and the wire forms a real
riveting a (Fig. 8). The pieces of steel forming fastening are set trans-
versely to a channel D, where meet the ends of the wires of all the
rows. The wire which it is desired to fix comes on to the edges of the
slit while still remaining under the tension of the weight which it
supports. A blow from a hammer is sufficient to drive it into the slit,
and the fastening is thus completed without any variation of tho
tension.
Variable Resistance at Different Points in the Length of the Piece.-
The interior pressures of the gasses decrease with sufficient rapidity from.
the breech to the mouth of the piece that it is in most cases only
requisite to envelope the reinforce with wire; the chase, then solely
formed of the metal of the central tube, being supposed to have of
itself sufficient resistance. This is the case assumed at Fig. 1 of the
Drawing. It may nevertheless be desirable to vary the resistance of the
tube from the breech to the mouth, for example, to employ thirty layers
of wire at the breech in the first third part of its length, twenty in the
second, and ten upon the last at the chase. The fastening channel of
the breech should contain the fastening picces intended to fix the wires
of the thirty layers. The first ten should extend without interruption.
the entire length from the breech to the mouth where they are fixed.
The succceding ten will extend two-thirds the length. The last ten
over only one-third. Figures 10 and 11 show this arrangement.

page_text: Method of Fastening the Intermediate Layers.-To fix the ends of
these intermediate layers two means may be used.
1º. At each of the points where a layer is to end there is made in the
metal of the central tube a channel G forming a projection equal to
that of the layers which reach this point; the bottom of this channel is
the extension of the general coiling surface which may be cylindrical or
conical. The two faces of the channel formed interiorly and exteriorly
spirally to the coiling pitch are cut by two slits which permit the
entrance and exit of the wires (see Fig. 10). The lower part of the
channel is occupied by the layers which only pass through it to be fixed
further on; the upper part carries the fastening pieces of the wires which
are to end at this point. Thus in the example assumed tho first channel,
starting from the mouth, would have a projection equal to that of thirty
layers, it would give passage to the ten first extending over the entire
length and intended to be fixed at the mouth, and would serve to fix
the succeeding ten which envelope the two first thirds. The second
channel would have a projection equal to that of thirty layers, it would
give passage to the first twenty and carry the fastenings of the last ten.
The second means (Fig. 11) consists in firstly, coiling the first
ten layers without break from the breech to the mouth where they are
fixed. On the outer surface of the tenth layer and at the point fixed
upon for the stoppage of the following is inserted a ring H carrying tho
fastenings of the ten succeeding layers. This ring is put on hot with a
pressure sufficient to secure it from displacement by the traction of the
wires of which it is the fastening.
Protection of the Wires.-To protect the layers of wires they are
covered with a tube of bronze or sheet copper set on hot so as to
penetrate into the interstices of the wires by its contraction and preserve
them from rust and against exterior blows or shocks. This precaution
is needless, for the layers of the reinforce which are sufficiently protected
by the breech-jacket or casing. The cannon represented, Fig. 1, being
enveloped only at the reinforce has no copper casing.
The Casing or Jacket Principle.-I have previously said that my
method consists in separating the two causes of rupture and in resisting
them separately by two distinct parts. The tube which I have just
described is intended to resist rupture in a generating line. Moreover
the breech could not with impunity be fixed to the central tube which

page_text: will generally be very thin. There remains therefore to describe the
piece intended to resist separation or parting of the breech. This piece
is a casing or jacket M (Fig. 1) enveloping the tube and carrying at the
same time the breech and the fastening for securing the picce upon its
carriage. The tube being invariable this casing or jacket will have to
experience no expansion following the radius, and will only have to
resist the longitudinal strain necessary to overcome the inertia which
the piece opposes to the recoil movement. I thus avoid the main cause
of parting at the breech which mostly arises from the rending of the
metal under the two rectangular actions which are produced at the
bottom of the bore in pieces loaded from the mouth, and at the bearing
surface of the breech-closing piece in breech-loading guns.
Construction and Fitting of the Casing or Jacket. -The jacket or
casing may be of any kind of metal, it will generally be found preferable
to make it of wrought iron, in which case, thanks to its slight thickness,
it may be made hollow by means of a wrought-iron plate rolled into a
cylinder and soldered, following a generating line. This casing or jacket
is inserted over the mouth of the piece and is arrested by a projection
abutting against the front m of the part to which the wires of the
reinforce are fastened. If the surface of the tube is conical this pro-
jection will be needless. The jacket is fixed at the back by a screw N
which finds a bearing against the face of the piece behind the tube A.
This screw will be solid if the cannon is intended to be loaded by the
mouth and hollow if to be loaded by the breech, the inner part then
serving as fulcrum to the breech-closing arrangement which in the
Drawing is supposed to be a breech screw with flutes breaking tho
threads. The jacket will usually be put on hot and the screw tightened
close up before the cooling. This operation is not intended to produce a
pressure on the tube, for the metal of the jacket in shrinking becomes
incrusted in the interstices of the wires; its object is to increase the
adhesion of the jacket or casing by spreading its bearing over a large
surface to completely protect the wire by its incrustation in the hollows,
and finally, and above all, to produce in a longitudinal direction upon
the jacket an initial tension analogous to that which the wire produces:
upon the central tube. The effect of this tension is to withdraw the
jacket from the violent shock of the discharge by creating beforehand a
longitudinal traction capable of partly equilibrating it. If the jacket is
put on cold the initial tension will be obtained by the rapid tightening

page_text: up of its back screw by the aid of a large lever arm, and if necessary by
windlasses. If on the other hand the breech closing is so arranged as to
press strongly against its seat, or against its screw threads if a screw be
used, it will be certain that the jacket will experience no shock and thus
realise the desired condition of having to resist only longitudinal tractions.
In the case of breech screws with broken threads, otherwise "fluted
screws," I give a special and novel arrangement; it consists in forming
the section of the screw threads following a helix instead of making it
following a generating line. In this manner the threads preserved may
occupy the entire circumference of tho screw and spread the pressure
equally over the entire section of the jacket instead of localising it as in
the second case upon three parts which bear a greater strain.
Method of Fixing the Piece upon its Carriage.-The preservation of
the carriages is very difficult in the case of light picces firing with heavy
charges, and to obviate this defect it has been proposed to interpose steel
springs between the piece and the carriage. To attain the same end I
use the following method of mounting the piece. For this purpose a
cylinder O (Figs. 1 and 1*) having trunnions P is set in the ordinary
manner on a carriage. The piece may slide freely in this cylinder like a
piston. In the space left between the cylinder and the piece are placed
springs or washers of india-rubber p, p, analogous to those used for the
buffers of railway waggons and separated by sheet iron washers r, r,
intended to isolate and center them; these washers bear against the rear
end P¹ of the cylinder. The cannon has a projecting ring Q which bears
against the india-rubber washers or the steel springs and compresses
them under the effect of the recoil. An india-rubber washer R is inter-
posed between this ring and the front end of the cylinder to deaden the
return shock of the piece when it is brought back to its primitive
position by the distension of the compressed washers. The object of this
arrangement is not to lessen the recoil but to deaden the shock of the
piece against its carriage by transforming it into a continuous pressure.
This arrangement presents another advantage, namely, that of permitting
the pointing to be completed without displacing the trail. For this
purpose it is only necessary to leave a slight play at S for the lodgment
of the piece in the rear end of the cylinder so that it may be moved
laterally to a slight extent by pivoting round the axis of the bearing
ring Q against the washers. The opening left for the passage of the
piece in the bottom of the cylinder is made following a straight lino

page_text: rizontally, the piece carrying two flattened parts S, S, rests upon the
ver horizontal surface of the opening, and the play only exists laterally.
igure 1 shows this arrangement). Two screws or an eccentric
rmit moving the piece in this opening and giving it a certain incli-
tion on the axis of the cylinder.
Having now described and ascertained the nature of my said Inven-
n, and in what manner the same is or may be performed, I would
ve it understood that I do not limit myself to the precise details
rein-before set forth and illustrated on the Drawing, as such may be
ried while retaining the essential features of my Invention, and that
at I claim as secured to me by the herein-before in part recited Letter
tent is,-
Firstly. The separation in the piece of the two parts intended to resist
rsting in a generating line or a parting from the breech, substantially
specified.
Secondly. In relation to the construction of the tube:-
(a). The practical realization of the principle which consists in storing
by the manufacture upon the central tube a sum of constant
resistance exactly ascertained capable of partially or wholly
cquilibrating the pressures of the gas and giving the measure
of the invariable resistance of the piece which is independent
of the quality of the central tube.
(b). For attaining this object the elastic metallic wires coiled under
constant and measured tension by a weight, and as a con-
sequence the proportionality of the resistance to the weight of
wire used, the wire being at pleasure hardened iron, steel, but
preferably piano cord wire which unites in the highest degree all
the qualities required, the whole substantially as specified.
Thirdly. In relation to the means of executing the tube :-
(a). The arrangement of the wire in successive layers travelling in
the same direction and having their independent fastenings.
(b). The method of coiling under constant weight and the principle of
the machines suitable for realizing this result automatically.
(c). The method of fastening under tension by insertion of the wire
into grooves made in picces of steel, or by compression
between two corrugated pieces.