IMPROVE- MENTS IN HARPOON GUNS AND AMMUNITION
Year: 1857

page_text: LETTERS PATENT to Robert Tindall, junior, of Fraserbugh, in the County
of Aberdeen, North Britain, Engineer, for the Invention of "IMPROVE-
MENTS IN HARPOON GUNS AND AMMUNITION."
Sealed the 3rd July 1857, and dated the 20th April 1857.
PROVISIONAL SPECIFICATION left by the said Robert Tindall at the
Office of the Commissioners of Patents, with his Petition, on the 20th
April 1857.
I, ROBERT TINDALL, junior, of Fraserbugh, in the County of Aberdeen,
North Britain, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN HARPOON GUNS AND AMMUNITION," to be as follows, that
is to say:
This Invention relates to various improvements in harpoon guns such as
are used in the whale fishery, and in the ammunition or apparatus to be used
therewith; the objects of the Invention being the obtainment of precision in
firing, non-liability to derangement, holding the fish in whatever position the
(expanding) harpoon is lodged, and increased efficiency by the combination of
a bomb with the harpoon. The muzzle of the improved gun is of somewhat
smaller diameter than the rest of the barrel; this reduced part is for the fitting
on of a ferrule or collar, contained in the centre of the harpoon spade or head,
when the harpoon is to be discharged. This ferrule has attached on each

page_text: side a short barbed harpoon piece, formed like the common harpoon, these
barpoon pieces being turned backwards with their barbed ends towards the
gun barrel. The line is attached to these harpoon pieces by means of a
thimble, connecting it with a shackle jointed to the harpoon pieces. The gun
is loaded with a long cylindro-conoidal ball or missile, a short piece of the
after end of which is made to fit exactly to the bore of the gun, whilst the rest
is of a reduced diameter, terminating in a cone or point. The mouth of the
harpoon ferrule fits exactly to the smaller forward portion of the cylindrical
ball, and it is turned out internally to fit to the angle forming the connection
between the larger and smaller diameters of the ball. When the gun is
loaded the ball is entered into the barrel close up to the powder of the charge,
and the ferrule with its duplex barpoon being placed upon the muzzle, it
follows, that when the weapon is discharged the ball on emerging enters the
ferrule, but being caught therein by its shoulder it carries away the duplex
harpoon and the line along with it. The ball and harpoon thus enter the
:fish together.
Another portion of the Invention relates to an expanding harpoon, or
harpoon shot, to be used in combination with the duplex harpoon already
described, and instead of the plain cylindrical shot. When closed this
expanding harpoon presents the appearance of a plain cylinder, the two
harpoon pieces or arms which it carries being folded down and retained by
the barrel of the gun. A spring is placed within this harpoon contrived to
act upon the two harpoon arms, so that when the harpoon leaves the muzzle
they are thrown out to a certain distance by this spring action. When the
harpoon lodges in the fish the pull upon the line expands the harpoon arms to
their full extent. The arms of this expanding barpoon or shot are disposed
at right angles to those of the main duplex harpoon, so that when the
expanding harpoon or shot carries away the other harpoon from the muzzle of
the gun, so that in any position at least one of the pairs of harpoon arms will
gain a secure hold in the fish when the latter is bit.
In carrying out this arrangement, two small studs are fixed in the forward
end of the expanding harpoon shot, one on each side, and fitted to work as rifle
pieces in rifle grooves formed in the gun's barrel. These internal grooves may
either be parallel with the axis of the gun's bore or twisted or rifled, and their
action is to answer as a guide to secure the right set of the relative positions of
the two sets of harpoon arms. The studs serve also to guide the cylinder in
the centre of the gun. This expanding harpoon shot may either have a conical
or pointed front end, or it may have a conical cap fitted to it; but when used
in conjunction with a bomb or shell, the end is squared and slightly reduced

page_text: for a short distance, to enter into the after end of the bomb. This bomb is
cylindro-conoidal, and it is charged with combustible and detonating or
explosive matter. When it is to be used with the expanding harpoon shot
the latter has two opposite longitudinal grooves cut in it, running from the
front end nearly to the after end, and terminating in nipples set at right angles
to the bevilled portion of the cylinder. Two tubes, attached to the bomb and
filled with a slow ignition composition, are fitted into those grooves, and are
fired by the explosion of percussion caps placed on the nipples at the instant
of leaving tlie gun.
In these arrangements of harpoon guns the arms or actual harpoon parts of
the apparatus act like the feathers of an arrow in guiding the weapon in its
flight. In using the common harpoon the fish is often lost from the breaking
of the shank, but with the improved apparatus this difficulty is entirely
removed, inasmuch as the twisting and strain after the harpoon is lodged in
the fish are entirely borne by the line. The duplex arrangement of the
harpoon armis crossing each other in their action also insures a firm hold in
the fish.
In another modification of harpoon comprehended under these improve-
ments, the actual head or holding portion of the weapon is of the common
form, and is fitted with a solid cylindrical shank, which is passed through a
central hole in a short cross piece, which fits upon the muzzle of the gun at
such a distance as will allow of the escape of the compressed air from the
barrel when the gun is fired. To this cross piece is attached the shackle for
connection with the line, as well as a pair of wings or feather pieces of thin
sheet iron, one on each side, for directing the harpoon's flight. The after end
of the harpoon shank has a stud or collar piece upon it, and when the gun is
fired this collar piece strikes against the arm through which the shank is
passed, and thus carries the line along with it. To render the harpoon gun
accurate in 'aiming, it is fitted with a self-adjusting sight, which operates quite
irrespective of the range. The gun is supported in the usual manner upon a
swivel fork, the arms or sides of which are prolonged upwards to a short
distance above the level of the centre pins or trunnions of the gun. These
prolongations are for carrying a pair of parallel vertical side rods, which
support a moveable sight bar upon a pin passing through the heads of the
rods. On the upper side of the barrel near the breech is a hinged stud or
sight, fitted with a spring acting upon a short back sail to throw it forward
upon the barrel. From the under side of the back portion of the sight bar
there depends a forked or looped rod, taking in the projecting end of the
folding sight on the barrel at its lower end, and the loop thus holds up the

page_text: folding sight. The front portion of the bar carries a quadrant piece, having
its tail passed through a guide staple attached to one of the vertical side rods
standing up above the trunnions, a pinching scrow being fitted here to set the
quadrant at any required point. The under side of the folding sight is formed
to a peculiar curve, which is determined and adjusted by experiment, which
curved surface acting upon the loop of the forked rod carried by the sight
bar causes the proper and proportionate degree of elevation or depression in
the sight, according to the position of the object aimed at. In taking aim, the
gunner first of all sets the sight bar in a line with the object. and fixes it, he
then looks over the sight and elevates or depresses the muzzle to the same
point, the folding sight adjusting itself to the proper elevation at the same
time.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Tindall in the Great Seal Patent Office on the 20th
October 1857...
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
TINDALL, junior, of Fraserburgh, in the County of Aberdeen, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of April, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Tindall, junior, Her special license that I, the said Robert
Tindall, junior, my executors, administrators, and assigns, or such others as
I, the said Robert Tindall, junior, my executors, administrators, or 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 "IMPROVE-
MENTS IN HARPOON GUNS AND AMMUNITION," upon the condition (amongst
others) that I, the said Robert Tindall, junior, 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 per-
formed, 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 Robert Tindall, junior, do hereby
leclare 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 in writing, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to say :-
My said Invention relates to various improvements in harpoon guns such
as are used in the whale fishery, and in the ammunition or apparatus to be
used therewith; the objects of the Invention being the obtainment of precision
in firing, non-liability to derangement, holding the fish in whatever position
the (expanding) harpoon is lodged, and increased efficiency by the combination
of a bomb with the harpoon. The muzzle of the improved gun is of some-
what smaller diameter than the rest of the barrel; this reduced part is for
the fitting on of a ferrule or collar, contained in the centre of the harpoon
spade or head, when the harpoon is to be discharged. This ferrule has attached
on each side a short barbed harpoon piece, formed like the common harpoon,
these harpoon pieces being turned backwards with their barbed end towards
the gun barrel. The line is attached to these harpoon pieces by means of a
thimble, connecting it with a shackle jointed to the harpoon pieces. The gun
is loaled with a long cylindro-conoidal ball or missile, a short piece of the
after end of which is made to fit exactly to the bore of the gun, whilst the rest
is of a reduced diameter, terminating in a coue or point. The mouth of the
harpoon ferrule fits exactly to the smaller forward portion of the cylindrical
ball, and it is turned out internally to fit to the angle forming the connection
between the larger and smaller diameters of the ball. When the gun is
loaded the ball is entered into the barrel close up to the powder of the charge,
and the ferrule with its duplex harpoon being placed upon the muzzle, it follows,
that when the weapon is discharged the ball on emerging enters the ferrule,
but being caught therein by its shoulder it carries away the duplex harpoon and
the line along with it. The ball and harpoon thus enter the fish together.
Another portion of the Invention relates to an expanding harpoon or
harpoon shot to be used in combination with the duplex harpoon already
described, and instead of the plain cylindrical shot. When closed this
expanding barpoon presents the appearance of a plain cylinder, the two
harpoon pieces or arms which it carries being folded down and retained by
the barrel of the gun. A spring is placed within this harpoon contrived to
act upon the two harpoon arms, so that when the harpoon leaves the
muzzle they are thrown out to a certain distance by this spring action.
When the harpoon lodges in the fish the pull upon the line expands the
harpoon arms to their full extent. The arms of this expanding harpoon or

page_text: shot are disposed at right angles to those of the main duplex harpoon, so that
when the expanding harpoon or shot carries away the other harpoon from the
muzzle of the gun, so that in any position at least one of the pairs of harpoon
arms will gain a secure hold in the fish when the latter is hit.
.
In carrying out this arrangement, two small studs are fixed in the forward end
of the expanding harpoon shot, one on each side, and fitted to work as rific pieces
in rifle grooves formed in the gun's barrel. These internal grooves may either
be parallel with the axis of the gun's bore or twisted or rifled, and their
action is to answer as a guide to secure the right set of the relative positions
of the two sets of harpoon arms. The studs serve also to guide the cylinder
in the centre of the gun. This expanding harpoon shot may either have a
conical or pointed front end, or it may have a conical cap fitted to it; but
when used in conjunction with a bomb or shell, the end is squared and
slightly reduced for a short distance to enter into the after end of the bomb.
This bomb is cylindro-conoidal, and it is charged with combustible and deto-
nating or explosive matter. When it is to be used with the expanding
harpoon shot the latter has two opposite longitudinal grooves cut in it, running
from the front end nearly to the after end, and terminating in nipples set at
right angles to the bevilled portion of the cylinder. Two tubes attached to
the bomb and filled with a slow ignition composition are fitted into these
grooves, and are fired by the explosion of percussion caps placed on the
nipples at the instant of leaving the gun.
In these arrangements of harpoon guns the arms or actual harpoon parts
of the apparatus act liko the feathers of an arrow in guiding the weapon in
its flight. In using the common harpoon the fish is often lost from the breaking
of the shank, but with tho improved apparatus this difficulty is entirely removed,
inasmuch as the twisting and strain after the harpoon is lodged in the fish are
entirely borne by the line. The duplex arrangement of the harpoon arms
crossing each other in their action also insures a firm hold in the fish.
In another modification of harpoon comprehended under these improve-
ments, the actual head or holding portion of the weapon is of the common
form, and is fitted with a solid cylindrical shank, which is passed through a
central hole in a short cross piece, which fits upon the muzzle of the gun at
such a distance as will allow of the escape of the compressed air from the
barrel when the gun is fired. To this cross piece is attached the shackle for
connection with the lines, as well as a pair of wings or feather pieces of thin
sheet iron, one on each side, for directing the harpoon's flight.
The after end of the harpoon shank has a stud or collar piece upon it, and
when the gun is fired this, collar piece strikes against the arm through which

page_text: the shank is passed, and thus carries the line along with it. To render the
harpoon gun accurate in aiming, it is fitted with a self-adjusting sight, which
operates quite irrespective of the rango. The gun is supported in the usual
manner upon a swivel fork, the arms or sides of which are prolonged upwards
to a short distance above the level of the centre pins or trunnions of the gun.
These prolongations are for carrying a pair of parallel vertical side rods, which
support a moveable sight bar upon a pin passing through the heads of the
rods. On the upper side of the barrel near the breech is a hinged stud or
sight, fitted with a spring acting upon a short back tail to throw it forward
upon the barrel. From the under side of the back portion of the sight bar
there depends a forked or looped rod, taking in the projecting end of the folding
sight on the barrel at its lower end, and the loop thus holds up the folding sight.
The front portion of the bar carries a quadrant piece, having its tail passed
through a guide staple attached to one of the vertical side rods standing up
above the trunnions, a pinching screw being fitted here to set the quadrant at
any required point. The under side of the folding sight is formed to a peculiar
curve, which is determined and adjusted by experiment, which curved surface
acting upon the loop of the forked rod, carried by the sight bar, causes the
proper and proportionate degree of elevation or depression in the sight, accord-
ing to the position of the object aimed at. In taking aim, the gunner first of
all sets the sight bar in a line with the object and fixes it. He then looks
over the sight and elevates or depresses the muzzle to the same point, the
folding sight adjusting itself to the proper elevator at the same time.
And in order that my said Invention may be properly understood I shall
now proceed to describe the several illustrative Figures on the explanatory
Sheet of Drawings, which I have hereunto appended for the purpose of
showing certain modifications under which my improvements may be judi-
ciously carried out in practice.
Figure 1 on my Sheet of Drawings is a plan of the outer or muzzle end of
the barrel of a harpoon gun, partially in section, and showing one modification
of a cylindro-conoidal ball or missile to be used therowith, also an improved
harpoon "spade" or head, which is shown partially in section, and fitted to the
muzzle end of the barrel; Figure 2 is an elevation of an expanded harpoon
fitted to a shell or exploding missile; Figure 8 is a plan, partially in section,
of the expanding harpoon used in conjunction with a harpoon "spade" or
head; Figure 4 is a modification of the arrangement shown in Figure 3, in
which the harpoon is connected to a shell filled with an explosive compound;
Figure 5 is a partially sectional plan, showing an expanding harpoon "spade"
or head fitted to the muzzle of a harpoon gun; Figure 6 is a plan, partially

page_text: in section, of an improved harpoon, in which the line is attached to the muzzle
of the gun, and vanos of thin metal resembling the feathers of an arrow are
connected to the tail of the harpoon to guide it in its flight through the air;
Figure 7 is an elevation of a harpoon gun fitted with a mechanical arrange-
ment for insuring accuracy of aim, irrespective of the distance of the object
aimed at. Figure 8 is à corresponding side view of a harpoon gun, showing
another arrangement for facilitating the adjustment of the gun when taking
aim with it.
In the modification of my improved harpoon and missile, shown in Figure 1
on my Sheet of Drawings, which is the simplest arrangement of my improved
harpoons, A is the outer or muzzle end of the barrel, which is made some-
what smaller upon the exterior by filing away or turning down the metal near
the mouth of the piece. The reduced portion B may extend for about an inch
and a half down the barrel, where it forms a shoulder, against which the
ferrule of the harpoon "spade" or head abuts.
In this modification the harpoon is carried through the air by means of a
cylindro-conoidal projectile C, the base or backward end of which C' fits the
barrel, whilst the other portion is of somewhat smaller diameter. At the end
of the smaller part of the projectile C is fitted a ring of copper, lead, or
other soft nietal D; this ring of metal abuts against the shoulder of the larger
part of the projectile. The harpoon "spade" consists of a double barb forged
to a ring or ferrule E; the two barbs or prongs F project backwards, similar to
the "spade" of an ordinary harpoon. The ferrule E is made to fit the
reduced part B of the barrel A; there is also an aperture through the ferrule,
corresponding to the size of the smaller part of the projectile C. A slot is
made in each barb at its junction with the ferrule E, and a shackle or bow G
is fitted thereto. The line H is attached to the shackle G by means of a
"thimble or concave ring of metal I. In using this improved harpoon, the
gun is loaded with its charge of powder, the projectilo C with its soft metal
ring D is put down the barrel next to the powder, and the harpoon is put
on to the end of the barrel.
Upon firing the gun, the smaller part of the projectile passes through the
orifice in the ring E, but is prevented from passing completely through it by
the ring D, which rests against the butt end C', and is larger than the aperture
in the ring E. The harpoon is consequently carried forward with the projectile
and are together lodged in the whale or object aimed at. The object of fitting
the ring of softer metal D at the shoulder of the projectile C is to lessen the
shock or blow of the projectile when it strikes against the inner part of the
ring or ferrule E....
'

page_text: The modification of my improvements shown in Figure 2 on my Sheet of
illustrative Drawings consists of an expanding harpoon, the barbs or prongs
which open or expand after the harpoon leaves the gun. The harpoon J
corresponds.in .its shape to the projectile C, Figure i, but is made longer.
The larger part K is made to fit the barrel of the gun, and there are two small
studs L projecting from its surface. These studs are made on opposite sides of
the harpoon, and they fit into longitudinal.or spiral grooves made inside the
barrel, and serve to guide the harpoon in the centre of the barrel, and increase
its extent of range and accuracy of flight. A longitudinal slot M is made in
the smaller part of the harpoon, in which the barbs or prongs N are jointed.
When the harpoon is put into the gun, the barbs are pressed together, so
as.to lie within the slot M; a spring is fitted between the barbs, which causes
them to expand the instant the harpoon leaves the mouth of the barrel. This
spring and barbs are shown expanded in Figure 4. To prevent the barbs from
being broken off by the sudden jerk when the projectile strikes an object, the
upper part of the slot M is packed with cork, leather, or other elastic material,
which presses against the back of the hinge and lessens the force of the
blow.
In Figure 2 the harpoon is shown attached to a shell or case O filled with
gunpowder or other explosive compound. The contents of the shell are
ignited by means of percussion caps which are put on the nipples P; for this
purpose they must be made tubular, similar to the nipple of rifle. The
harpoon has two grooves or tubular passages Q, which communicate with each
of the nipples P;. a piece of fuse is put into these passages which fires the
shell when the caps are exploded by striking against the shoulders of the
ferrule. The expanding harpoon may be used without tho, shell O, in which
caso a conical cap of metal is fitted on to the end, of the smaller part of
the harpoon.
In Figure 3 on my Sheet of Drawings an arrangement is shown in which
the expanding harpoon is used in conjunction with a modified form of harpoon
"spade" or head fitted to the muzzle of the barrel, as in Figure 1.. In this
arrangement the barrel of the piece is broken away, and shews one of tho
rifled grooves, in which the studs L on the expanding harpoon fit. The
harpoon B is similar in arrangement to that shown in Figure 2, excepting that
it is not loaded with. an explosive charge. The barbs N are fitted with an
expanding spring R, and an elastic recoil. stuffing. S, both in front of the joint
of the barbs and behind the pin of the joint, the holes being elongated for, the
purpose of inserting the elastic substance.. A stud L at each side: of the
forward part of the expanding harpoon is made to fit the grooves in the barrel.

page_text: These studs are made of tin, lead, or other soft metal, are cut off as the
projectile passes through the narrow part of the ferrulo E. The harpoon
"spade" or head F which fits the end of the barrel is made with a shackle
.or bow G, by means of which the line H is attached thereto. In using this
arrangement of harpoon, it is of importance that the prongs or barbs of the
two harpoons shall be when fired at right angles to each other, so as to retain
'a very firm hold of the object fired into. The studs L lie in the same plane
as the prongs or barbs N, and as these studs enter the grooves in the barrel,
the position of the barbs N, when the expanding harpoon emerges from the
barrel, is at once determined; but it is necessary to put the "spade" or
head F on the end of the barrel so that its prongs or barbs shall be at right
angles to the expanding harpoon. This is done by fitting a pin near the
muzzle of the barrel and making a corresponding groove or slot in the ferrulo
of the harpoon F, so that when put on the barrel its prongs are placed at right
angles to those of the expanding harpoon. The expanding harpoon is fitted
with a conical point T, either screwed or pinned to the harpoon J.
In Figure 4 the expanding harpoon is shown fitted with a shell attached
by a screw to the end of the harpoon in place of the metal point T. In this
arrangement the shell consists of an iron case U, fitted internally with a tin
case V, which is filled with powder. A small central tube W runs from the for-
ward end of the shell down through the charge of powder to the back end. The
point of the case U is made with a nipple to receive a percussion cap X. The
iron shell U has a number of holes Y made in it to allow of the lateral action
of the powder; there are also two holes Z bored in an angular direction near
the point of the shell, and communicating with the tubular passage in which
the fuse is placed. Theso holes facilitate its combustion upon the exploding
.of the percussion cap X. A disc of thin soft metal X is fitted inside the
ferrule of the harpoon "spade" or lead, and covers tho aperture of the barrel,
as shown in the partially sectional view, Figure 5, of my Sheet of Drawings.
The soft metal studs L may be in this arrangement put in near the point of
tho shell U, as shown dotted at L', instead of at the end of the harpoon J.
The expanding harpoon is put inside the barrel and pushed down to the
chargo and the spade or head fixed on the end of the barrel. When the
charge is fired, the cap X strikes against the disc of soft metal X and passes
through it; the blow, however, is sufficient to explode the cap X and ignite
the fuse. The shoulder of the larger end of the expanding harpoon comes
in contact with the contracted part of the ferrule and carries the harpoon
spade and line with it; meanwhile the fuse burns slowly away during the
flight of the harpoon until it reaches the charge of powder or composition,

page_text: which is intended to explode after the harpoon is lodged in the whale. and
fill it with gaseous matters.
In Figure 5 of my Drawings the arrangement of the harpoon is modified
from that shown in Figures 1 to 3. The harpoon "spade" or head is shown
fitted to the end of the barrel A, the expanding harpoon being supposed to
be down the barrel of the piece. The disc of soft metal X is shown in section
covering the mouth of the barrel. The spade or head is made with barbed
prongs F jointed; these prongs lie close to the sides of the "spade" during
its flight through the air. When the harpoon buries itself in the whale the
drag of the line causes the prongs to expand, and thereby maintain a very
firm hold. In this arrangement the shackle G is made of stout wire, passed
through the links a, and twisted firmly together. The links a are jointed to
the back part of the spade to give flexibility to the whole, and previously to
putting the parts together a thimble I, having the end of the whaling line
H spliced thereto, is passed on to the shackle.
Figure 6 of my Sheet of Drawings is a plan, showing my improvements
in the arrangement of the ordinary harpoon for firing from a gun. The shank
6 of the harpoon is a round bar of iron, somewhat enlarged at its lower end
c. The smaller part passes through a ring of metal d, which forms the ferrule.
The ferrule is made to fit the muzzle of the gun, the shank 6 sliding freely
in the ring d. A ring of copper or other soft metal e is put on to the end
of the shank b, against which the enlarged part c of the shank strikes when
the
gun is fired. From the sides of the ring d project two studs f, to which
is attached the shackle of twisted wire g. The nuts on the end of the studs
These vanes are made
its flight, and prevent
f servo also to secure the pair of vanes or blades h.
of thin sheet metal, and serve to guide the harpoon in
its taking the zig-zag course of an ordinary harpoon when fired from a gun.
The line is spliced to a "thimble," which is passed on to the bow of the
shackle, as before described. In this modification of my improvements the
spade" of the harpoon is of the ordinary shape, but any of the other forms
shown in my Sheet of Drawings may be used in lieu thereof.
The last part of my present Invention has reference to improvements in
the arrangement of harpoon guns to secure accuracy of aim therewith.
Figure 7 is an elevation, showing one modification of the same. The gun A
is supported in a forked swivel B, to the upper ends of which are attached
two side rods C. These rods serve to support a moveable sight bar D. The
after end of the sight bar is formed into a handle, for the convenience of
holding and adjusting, and its upper surface is made with a conically-shaped
groove, extending from end to end of the bar. To the under side of the sight

page_text: bar, and in front of the side rods C, is attached a quadrant E, the free end
of which passes through a staple screwed to one of the side rods C. The
quadrant may be fixed to the side rod at any desired point by means of a
pinching screw F. The sight bar is also furnished with a forked rod G, the
.lower end of, which is pressed against by a folding sight H, fitted at the
breech of the barrel. The folding sight or stadium E is hinged to the barrel,
and it is pressed forwards and against the forked rod G by a spring I. The
curvature of the sight II is determined by experiment previously to fitting it
to the gun, so that its curved part when acting upon the end of the rod G
shall cause the barrel of the gun to be elevated or depressel in accordance
with the position of the object aimed at. In taking aim with a gun arranged
in this manner, the gunner first brings the sight bar D in a line with the
.object; the bar is instantly fastened in that position by the pinching screw
.F; he then looks over the point of the sight II, and brings it and the sight
J at the end of the barrel in a line with the object, the moveable sight
adjusting itself to the proper elevation at the same time, so that with this
-arrangement there is no necessity for the marksman to estimate or make any
'allowance for the distance of the object he is aiming at.
. Another modification for attaining accuracy of aim with harpoon guns is
shown in Figure 8 on my Sheet of Drawings. The gun A is carried upon a
pin, fastened through the forked ends of the swivel B, to which are attached
the side rods C. These rods partially support the sight bar D. The front
end of the sight bar is steadied by a guide K, attached to the barrel of the
picce. At the breech end of the barrel a brass plate L is fitted between two
supports M. The under edge of this plate is curved, and a forked arm N,
pendant from the sight bar D, moves to and fro on this curve when the gun
is clevated or depressed. The curvature of the plate L is determined by
experiment, like that of the moveable sight H, in Figure 7. The slots in
the plate through which the pins of the supports M pass likewise admit of
the plate being adjusted after fitting it to the gun; or the forked arm N 3
The weight of the
may be made moveable up or down on the sight bar D.
bar D keeps the pin O, in the forked ends of the rod N, up against the curved
plate L. The upper edge of the sight bar D, along which the marksman's
eye is directed in taking aim, is grooved to a concave forin, and when the
bar D is brought in a line with the object to be fired at the forked arm N 3
moves along the curve of the plate L, and thereby regulates the elevation or
depression of the muzzle.
These various arrangements and improvements in harpoon guns and ammu-
nition to be used therewith greatly diminish the difficulties attending the

page_text: of the ordinary guns, whilst the increased accuracy imparted to the flight of
the projectiles and harpoons by means of the improvements considerably lessen
the chances of missing the object fired at. Moreover, from the peculiar-arrange-
ment of the expanding harpoon and "spade," a whale when once struck with
them cannot break away from the firm hold which the quadruple barbs have
upon it.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of harpoon guns and
ammunition or projectiles to be used with the same, as herein-before
described.
Second, the use and application of harpoon "spades" or heads, which arc
carried to the object aimed at by means of cylindro-conoidal shot, or pro-
jectiles, as herein-before described.
'
Third, the arrangement and construction of expanding harpoons, in which
the prongs or barbs spring outwards upon the harpoon issuing from the barrel
of the gun, as herein-before described.
Fourth, the use and application of the expanding harpoon in conjunction
with harpoon "spades" or heads, which are carried to the object by means
of the expanding harpoons, as herein-before described.
Fifth, the arrangement and construction of harpoon " spades" or heads,
in which the prongs or barbs are jointed, and are folded inwards during the
flight of the spade or head, as herein-before described.
Sixth, the system or mode of attaching the whaling line to the "spade" or
head by means of shackles jointed thereto, as herein-before described.
Seventh, the use and application of shells or cases filled with explosive
matters, and used in conjunction with expanding harpoons and harpoon
"spades" or heads, either separate or combined, as herein-before described.
Eighth, the use and application of vanes or blades applied to harpoons of
the ordinary kind, the said vanes or blades being fitted to a moveable piece
of metal applied to the muzzle of the gun, and which serves to carry the
whaling line, as herein-before described.

page_text: Ninth, the mechanical arrangements for facilitating the use of harpoon
guns, and obtaining increased accuracy of aim therewith, as herein-before
described.
In witness whereof, I, the said Robert Tindall, junior, have hereunto set
my hand and seal, this Nineteenth day of October, One thousand 5
eight hundred and fifty-seven.
ROBERT TINDALL, JUN. (L.S.)
ROBERT TINDALL, JUN. (L.s.)