IMPROVE- MENTS IN PROJECTILES AND ORDNANCE
Year: 1861

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, for the Invention of " IMPROVE-
MENTS IN PROJECTILES AND ORDNANCE."
Sealed the 24th October 1861, and dated the 27th April 1861.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents; with his Petition, on the 27th
April 1861.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
5 City of London, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN PROJECTILES AND ORDNANCE," to be as follows:-
My Invention relates, firstly, to that class of projectiles which are caused
to revolve, during their passage along the chase or bore of a gun, by means
of the reactive force generated by the emission of a portion of the elastic gases
O resulting from the ignition of the charge of powder employed to propel the
projectile.
And in order that the nature and extent of my present improvements in
projectiles may be more clearly ascertained, I would state that a Patent was
granted to me, bearing date the 24th day of November 1854, No. 2489, in

page_text: I
the Specification of which is shewn and described a method of giving rotation
to projectiles by forming two or more tubular passages in the interior of the
projectile, and in a direction parallel to its longer axis, the passages so formed
having sudden bends or elbows at right angles, or nearly so, to their former
course, and in the direction of a tangent to the circumference of the pro-
jectile, and it has since been proposed to use ordinary elongated projectiles
with spiral or twisted grooves or passages at the peripheries of the projectile.
Now, my present Invention consists in forming sunken channels on the
exterior surface of the projectile in lieu of tubular passages in its interior.
form these channels in a line parallel with its longest axis, each of them
being made to terminate in a sudden bend or elbow, having a direction at
right angles or nearly so to their former course, and at a tangent to
the circumference of the projectile, around the centre of which I form a
raised band in which these channels are made, thus giving ready ingress and
egress to the escaping gases. The raised band is formed to fit the bore of the
gun, and I prefer to make both ends of the projectile of the same curved or
conical shape, and of the same weight and dimensions, so that the centre of
gravity shall coincide as nearly as may be with the centre of the band which
fits the
gun.
When projectiles intended to revolve by the simple emission of gases in a
smooth cylindrical bore, according to my present Invention, are to be made in
forged malleable iron or steel, the channels may be cut or planed out of the
solid metal, but such projectiles may be cast in steel_ or malleable iron, or in
cast iron in moulds of sand, loam, clay, or iron, and may in such case have the
before-named channels formed therein by founding. When cast iron is
employed for their manufacture, I prefer to subject the shots, after they are
cast, to the process of annealing in chambers packed with oxide of zinc or iron
so as to decarbonize and render malleable the exterior portion of them, whereby
they will become less liable to break into fragments when fixed against iron
plates or other hard. surfaces. I perfect the shape of such projectiles by
turning in a lathe the central raised band, or, if desired, the whole of their
exterior surface may be turned, or I force the projectiles through a chilled
iron or hard steel die, so as to perfect, the cylindrical part by a means
analagous to that of wiredrawing, after which I tin, galvanize, or electro-.
plate them, and then force them through another die so as to correct any
inequality of surface produced by the metallic coating, and thus ensure the
projectile fitting freely and accurately into the gun, and at the same time
protect it from corrosion.

page_text: My improvements in the construction of ordnance relate, firstly, to cast-iron
guns that have been made for the purpose of throwing spherical projectiles,
and consists in adapting them for throwing elongated projectiles of greater
weight than the shots they were originally designed for, without, however,
subjecting the gun to so great a strain as would result from the employment
of elongated projectiles of a diameter equal to the original bore of the gun.
For this purpose I prefer to bore out the gun truly, and in doing so I form a
series of small concentric or spiral grooves such as are formed by a V-shaped
tool in ordinary turning. I then take a drawn or hammered metal tube in
its annealed state, and of such a size as may be tightly forced into the gun,
after which an instrument, known in the tube-drawing trade as a "bull-head,"
may be forced down the tube, the instrument being of such a size as will
cause the annealed tube to expand. This process is to be repeated several
times, using a larger instrument on each occasion, by which means the tube
will be made to expand and embed itself in the grooves before named, and
will thus be held firmly in its place and in close contact at all parts with the
cast iron; at the same time the malleable metal tube will be considerably
hardened and condensed by these operations, and will be in a better condition
to withstand the abrasion of the shot, and the mechanical and chemical action
of the ignited gases, than cast metal in its porous state. Copper, gun metal,
aluminium, bronze, or other copper alloy may be employed to make these
tubes, but I prefer an alloy containing nickel; the harder kinds of German
silver thus compressed are capable of withstanding a great amount of wear,
and will be found especially suitable for this purpose. In breech-loading guns
the tube may extend entirely through them, but in guns loaded at the muzzle
the tube may be made with a closed end, or if left open, a cylindrical piece or
plug should be put in after the tube is fixed, and be upset by repeated blows,
and thus rendered air-tight. Cast-iron guns so lined will be better able to
bear the extra weight of an elongated projectile, firstly, because the diameter
of the bore exposed to pressure will be lessened; and, secondly, because an
addition will be made to the strength of the gun by the metal which forms the
lining. The gun will thus be rendered suitable for throwing a projectile of a
weight intermediate between that of the spherical shot it was originally
designed for, and the weight of an elongated projectile of a diameter that would
fit the original bore of the gun.
When a gun so lined requires to be rifled, I make small grooves length-
wise of the original bore, into which the exterior of the tube becomes
embedded, and will thus prevent the tube from turning round by the force of

page_text: the projectile; and although I have herein-before described how the expand-
ing of the tube is effected by forcing a steel instrument through it, I desire it
to be understood that a similar result may be obtained by the rotation of the
gun on a suitable fixed mandril, or by the rotation of a mandril baving an
enlarged end or burnisher, or having small rollers fitted to the end of it, by
which means the tube may be expanded and impressed into the grooves, while
the metal of which it is made will be hardened and condensed. In construct-
ing ordnance of malleable iron and steel, either by simply founding the gun
in these qualities of metal or by the process of forging, I also line them in
the manner herein described in order to preserve the bore from the effects of
damp and corrosion.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
26th October 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of April, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of
Jer reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Bessemer, Her special licence that I, the said Henry Bessemer,
my executors, administrators, and assigns, or such others as I, the sail
Henry Bessemer, 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
PROJECTILES AND ORDNANCE," upon the condition (amongst others) that I, the said
Ileniy Bessemer, 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.

page_text: NOW KNOW YE, that I, the said Henry Bessemer, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following.
statement thereof, that is to say:-
My Invention relates, firstly, to that class of projectiles which are caused to
revolve during their passage along the chase or bore of a gun by means of the
reactive force, generated by the emission of a portion of the clastic gases
resulting from the ignition of the charge of powder employed to propel the
projectile..
And in order that the nature and extent of my present improvements in
projectiles may be more clearly ascertained, I would state that a Patent was
granted to me bearing date the 24th day of November 1854, No. 2489, in
the Specification of which is shewn and described a method of giving rotation
to projectiles by forming two or more tubular passages in the interior of the
projectile, and in a direction parallel to its longer axis, the passages so formed
having sudden bends or elbows at right angles, or nearly so, to their former
course, and in the direction of a tangent to the circumference of the projectile,
and it has since been proposed by others to use ordinary elongated projectiles
with spiral or twisted grooves or passages at the peripheries of the projectile,
and I mention this fact in order to shew that I lay no claim thereto.
Now my present Invention consists in forming sunken channels on the
exterior surface of the projectile in lieu of tubular passages in its. interior, as
described in my former Patent herein-before referred to.. I form these
channels in a line parallel with its longest axis, each of them being made to
terminate in a sudden bend or elbow having a direction at right angles, or
nearly so, to their former course, and at a tangent to the circumference of the
projectile, around the centre of which I form a raised band in which these
channels are made, thus giving ready ingress and egress to the escaping gases
the raised band is formed to fit the bore of the gun, as shewn in Figure 1 of
the annexed Sheet of Drawings, which represent a
portion of the gun in section
at a, and the projectile b closely fitting to it, the interior surface of the bore
forming a fourth side to and completing each of the channels. c. I prefer to
make both ends of the projectile of the same curved or conical shape, and of
the same weight and dimensions, so that the centre of gravity shall coincide as
nearly as may be with the centre of the band or raised part which fits the
gun. In some cases, however, it may be preferable to provide a means of
preventing the projectile from being deflected when striking against an iron or
other hard surface at an angle. For this purpose I form on the front end of
the projectile a sort of gouge or punch, the cutting angles of which are very

page_text: obtuse; I prefer to make it cylindrical, or nearly so, the front part being
slightly hollowed, as shewn in section at Figure 8, where d is the projectile
and e the steel punch inserted in the front end of it; should the projectile,
however, be made wholly of steel, the punch may form a part of the general
mass at f. I have shewn a piece of an armour plate against which the pro-
jectile is advancing, and into which the sharp-angled punch would bury itself,
and thus prevent that deflection of the projectile which would otherwise take
place.
In making projectiles intended to revolve during their passage along the
bore of the gun by the reactive force of the elastic gases escaping at a tangent
to the projectile, in the manner herein shewn; the size or number of the
channels may be varied, but in all cases their united areas must be such as will
cause the projectile to revolve with the required velocity. In firing such pro-
jectiles it has been found that a considerable velocity of rotation is produced
when the united areas of the several passages or channels are equal to the
difference in area between the bore of an ordinary gun and the spherical
projectile now used therein, that is, when the area of outlet or windage by
these channels is equal to the area of windage in ordinary round shot.
In order that the form and mode which I prefer of arranging these channels
may be fully understood, I have shown at Figure 2 of the annexed Drawings
an elevation of a projectile having four channels g running parallel with its
longer axis near the foremost part of the body of the shot; these channels
make a sudden bend or turn at h in a direction at right angles to their former
course, so that the gases may be emitted from the end of the passages h in
the direction of a tangent to its circumference (and thence escaping around
the fore part of the projectile) cause it to revolve in the opposite direction
with a force and velocity dependant on the area of the emission apertures and
the pressure of the escaping gases; Figure 3 is an end elevation, and Figure 4
a cross section taken through the body of the projectile, shewing the position
of the several channels.
Another modification of this kind of projectile is shewn in elevation at
Figure 5, and in end elevation and cross section at Figures 6 and 7; in this
modification of the projectile the channels m are made parallel with its longer
axis, and are diverted from that course at n in a direction somewhat less than
a right angle, and also at a tangent to the circumference. In all cases I
prefer that the main part of these channels should be of larger area than the
orifice of escape, in order the more completely to keep up the pressure of the
gases and insure their full reactive effect.
When projectiles intended to revolve by the simple emission of gases. in a

page_text: smooth cylindrical bore, according to my present Invention, are to be made in
forged malleable iron or steel, the channels may be cut or planed out of the
solid metal, but such projectiles may be cast in steel or malleable iron, or in
cast iron, in moulds of sand, loam, clay, or iron, and may in such case have
the before-named channels formed therein by founding; when cast iron is
employed for their manufacture I prefer to subject the shots after they are
cast to the process of annealing in chambers packed with oxide of zinc or iron,
so as to decarbonize and render malleable the exterior portion of them in a
manner well understood and practised in the manufacture of what is known as
malleable iron castings, whereby they will become less liable to break into
fragments when fired against iron plates or other hard surfaces. I perfect the
shape of such projectiles by turning in a lathe the central raised band, or if
desired the whole of their exterior surface may be turned, or I force the pro-
jectiles through a chilled iron or hard steel die, so as to perfect the cylindrical
part by a means analogous to that of wire drawing, after which I tin, galvanize,
or electro-plate them, and then force them through another die so as to correct
any inequality of surface produced by the metallic coating, and thus ensure
the projectile fitting freely and accurately into the gun, and at the same time
protect it from corrosion.
My improvements in the construction of ordnance relate, firstly, to cast-iron
guns that have been made for the purpose of throwing spherical projectiles,
and consists in adapting them for throwing elongated projectiles of the same
or preferably of greater weight than the shots they were originally designed
for, without, however, subjecting the gun to so great a strain as would result
from the employment of elongated projectiles of a diameter equal to the
original bore of the gun. For this purpose I prefer to bore out the gun truly,
and in doing so I form a series of small concentric or spiral grooves, such as
are formed by a V-shaped tool in ordinary turning. I then take a drawn or
hammered metal tube in its annealed state, and of such a size as may be
tightly forced into the gun. The gun may be previously expanded by heat,
and the cold tube be inserted or forced into it while in this heated state, so that
its contractile force may be brought to bear on the exterior surface of the tube
or lining; after which .an instrument known in the tube-drawing trade as a
"bull-head" may be forced down the tube, the instrument being of such a
size as will cause the annealed tube to expand. This process is to be repeated
several times, using a larger instrument on each occasion, by which means the
tube will be made to expand and embed itself in the grooves before named,
and will thus be held firmly in its place; and in close contact at all parts with

page_text: the cast iron, at the same time the malleable metal tube will be considerably
hardened and condensed by these operations, and will be in a better condition
to withstand the abrasion of the shot, and the mechanical and chemical action
of the ignited gases, than cast metal in its porous state. Copper, gun metal,
brass, aluminium, bronze, copper, and phosphorous, or other copper alloy may
be employed to make these tubes, but I prefer an alloy of copper containing.a
small quantity of nickel. The harder kinds of German silver thus compressed
by drawing, are capable of withstanding a great amount of wear, and will be
found especially suitable for this purpose; and although I prefer to use such
alloys of copper, because they resist corrosion better than iron in any of the
conditions in which that metal is known, it will be obvious that many of the
advantages of this system of lining and reducing the bore of cast-iron guns, and
adapting them for discharging rifled or other elongated projectiles, may be
obtained by forming the tube or lining of wrought iron or wrought steel, or
by forming it of homogeneous Bessemer iron or steel, the latter being of a mild
and soft quality.
.
In breech-loading guns the tube may extend entirely through them, but in
guns loaded at the muzzle the tube may be made with a closed end, or if left
open a cylindrical piece or plug should be put in after the tube is fixed, and
be upset" by repeated blows, and thus rendered air-tight.
In order that the mode which I prefer of fixing these tubes may be fully
understood, I have shown at Figures 9 and 10 a longitudinal and cross section
of a thirty-pounder cast-iron gun of about 6.25 inches diameter of bore; into
this gun a tube of three-fourths of an inch in thickness may be fitted, whereby
the internal diameter exposed to the bursting force of the charge will be reduced
to 4:75 inches, while the original gun will be greatly strengthened by the addi-
tion of the metal tube, which will form an integral part of it. Cast-iron guns
so lined will be better able to bear the extra weight of an elongated projectile,
firstly, because the diameter of the bore éxposed to pressure will be lessened;
and, secondly, because an addition will be made to the strength of the gun by
the metal which forms the lining. The gun will thus be rendered suitable
for throwing a projectile of a weight intermediate between that of the spherical
shot it was originally designed for, and the weight of an elongated projectile
of a diameter that would fit the original bore of the gun.
Figures 11, 12, and 13 represent sections of a portion of this gun on a
larger scale; on the interior surface of it small spiral grooves t are formed at
short intervals apart, or closely ranged like the threads of a fine screw; and at
the breech end of the gun a recess is formed around its interior, as shown

page_text: 35
"
at, r. The gun 'thus prepared is to have the tubes, s, forced into it; the
tube having been originally manufactured with one closed end, or one end of
it having been previously stopped up by brazing, soldering, or "burning'
copper or other suitable end piece s* to it, so as to form an air-tight breech end
to the tube. A cylindrical piece u of annealed copper, iron, or other suitable
metal at a red heat, or otherwise, is then inserted in the tube, and; a great
pressure applied thereto either by.an hydraulic apparatus. or by repeated blows
from a heavy steel mandril, so as "to upset or expand the mass of metal
and cause it also to expand the tube s, 8, so much as
to fill up the
annular recess r, r, as shewn in Figure 13, and whereby the tubes will be
firmly held in its position, and at the same time a firm and durable end to the
bore will be formed. In employing metals or alloys having a greater expan-
sion by heat than the metal of which the gun is formed, the grooves t may be
omitted, and the tube be allowed to expand and contract freely, being held
only at the breech in the manner described; but should it be found desirable in
some cases to make a more perfect union, the interior of the gun and the exterior
of the tube may be tinned or galvanized, and be put together while the metal
or solder is still in a fluid state, by which means the tube and the gun will
become firmly united. When a gun so lined requires to be rifled, I make
small grooves lengthwise of the original bore, into which the exterior of the
tube becomes embedded, and will thus prevent the tube from turning round
by force of the projectile, and although I have herein-before described how the
expanding of the tube is effected by forcing a steel instrument through it, I
desire it to be understood that a similar result may be obtained by the rotation
of the gun on a suitable fixed mandril, or by the rotation of a mandril having
an enlarged end or burnisher, or having small rollers fitted to the end of it,
by which means the tube may be expanded and impressed into the grooves,
while the metal of which it is made will be hardened and condensed.
I also desire it to be understood that in addition to the utilization of smooth-
bored guns (both of cast iron and of bronze or "gun metal") already constructed,
or used by lining them, and reducing their original bore, in [the manner herein-
before described, that an important part of my present Invention also
consists in constructing ordnance of malleable iron and steel, either by simply
founding the gun in either of these qualities of metal, or by the combined
pro-
cesses of founding and forging; in either of which cases I also line them in
the manner herein described, in order to preserve the bore from the effects of
damp and corrosion, and also in order to obtain the several other advantages
resulting from the combined structure of the gun; and I lay no claim simply

page_text: to the construction of guns in malleable iron or steel, whether founded or
forged, provided that the bore of such guns are not lined with a tube.
Having now described the nature of my Invention, and in what manner the
same is to be carried into effect, I desire it to be understood that I do not
confine myself to the precise details herein, given, provided the peculiar charac-
ter of my said Invention herein described be retained.
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Twenty-sixth day of October, in the year of our
Lord One thousand eight hundred and sixty-one.
HENRY BESSEMER. (L.s.)