IMPROVEMENTS IN HARPOON GUNS
Year: 1857

page_text: LETTERS PATENT to Alexander Mitchell, of Peterhead, in the County of
Aberdeen, North Britain, Machinist, for the Invention of "IMPROVEMENTS
IN HARPOON GUNS."
Scaled the 21st April 1857, and dated the 24th February 1857.
PROVISIONAL SPECIFICATION left by the said Alexander Mitchell at the
Office of the Commissioners of Patents, with his Petition, on the 24th
February 1857.
I, ALEXANDER MITCHELL, of Peterhead, in the County of Aberdeen, North
Britain, Machinist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN HARPOON GUNS," to be as follows, that is to say:--
This Invention relates to the improvement of what are known as "harpoon
guns" employed by whale fishers, and it consists of certain. arrangements
whereby the clevator bar, which is used for giving the gun its necessary
elevation in firing, is made adjustable, so as to suit accurately for different
distances.in firing. The harpoon itself is connected to the gun by a line of
a length equal to the longest range of the gun, and the elevator bar is
primarily set at the proper angle for. shooting at this extreme distance, but
tho bar is so arranged as to fall at the butt end of the gun when the instru-
ment is pointed at an object within this range. This adjusting action is
effected by connecting the elevator bar with the swivel pin on which the gun
moves, so that the bar rises or falls just as the gun is clevated or depressed.
With these arrangements the harpoon gun is rendered very much superio!
to the common instrument as regards accuracy of firing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Mitchell. in the Great Seal Patent Office on the
24th August 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MITCHELL, of Peterhead, in the County of Aberdeen, North Britain, Machinist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, 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 Alexander Mitchell, Her special license that I, the said Alexander
Mitchell, my executors, administrators, and assigns, or such others as I, the
said Alexander Mitchell, my exécutors, administrators, or assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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," upon the condition (amongst others) that I, the said
Alexander Mitchell, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Mitchell, 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 in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:-
บ
My said Invention relates to the improvement of what are known as
"harpoon guns" employed by whale fishers, and it consists of certain arrange-
ments whereby the elevator bar, which is used for giving the gun its necessary
elevation in firing, is made adjustable, so as to suit accurately for different
distances in firing. The harpoon itself is connected to the gun by a line of
a length equal to the longest range of the gun, and the elevator bar is
primarily set at the proper angle for shooting at this extreme distance, but
the bar is so arranged as to fall at the butt end of the gun when the instru-
ment is pointed at an object within this range. This adjusting action is effected
by connecting the elevator bar with the swivel pin on which the gun moves,

page_text: so that the bar rises or falls just as the gun is elevated or depressed. With
these arrangements the harpoon gun is rendered very much superior to the.
common instrument as regards accuracy of firing.
And in order that my said Invention may be properly understood I will
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 longitudinal elevation of one:
arrangement of my improved. harpoon gun; Figure 2 is an elevation of a
modification of the same.
In harpoon guns of the ordinary kind, a bar of metal fastened by screws to..
the upper part of the barrel' serves as a means of indicating the proper
elevation for firing at distant objects. But this fixed bar, which is technically.
known as an elevator bar, is altogether ineffective in practice; and unsuited to
the purpose for which it, is intended, so much so, that the marksman can
never be certain, when taking aim with a weapon of this kind, whether the
harpoon will strike the object intended or not.
Now, in order to render the weapon more effective in- use and easier to
manipulate, I fit to it a moveable self-adjusting elevator bar, certain. modifi-.
cations of which form the subject matter of this present Specification.
i
In Figure 1 of my illustrative Drawings the stock A of the gun. is of wood,
and is somewhat similar in the form of its outline to the stock of a pistol. :
The stock is made of a strength proportionate to the size and weight of the:
barrel. The butt end of the stock is tapered off to a diameter convenient for:
bolding when directing the gun. The barrel B of the piece is made from;
thirty to six and thirty inches in length, with a bore of two inches, decreasing
down to one and a half inches. The gun is fitted in the forked ends of a swivel C,.
the pin D of which unites the upper extremities of the swivel and passes
through the stock; this pin serves as an axis on which the gun moves in a.
vertical direction. The circular sweep or horizontal range of the barrel is.
obtained by means of the lower extremity of the swivel, which fits into a
metal eyo fixed in the bow of the whaling boat. The forked end of the
swivel have welded to them a horizontal branch or metal tail piece E on each.
side of the stock. These tail pieces E lio parallel to the sides of the stock,.
and extend backwards towards the butt end of the weapon. The swivel tail-
pieces E are connected with the elevator bar F by means of the side rods G;
the lower part of each of these side rods is secured by a bolt and nut to thu.
.

page_text: tail piece. The bolt or pin of each of the side rods G is capable of sliding
to and fro in a longitudinal slot made in the tail picce E, but is fixed at the
proper point in the slot by means of the nut, the sido rod turning freely on
the più ȧs upon a pivot; the pin passes through one of a series of holes in
the rod G. By means of these holes the length of the rods G can be adjusted
as required, but a further and more accurate adjustment is provided for by the
arrangement of the upper part of the side rods. At the upper extremity of
the rods G is an eye, through which a screw H passes; the length of tho
adjusting screw H is regulated by means of a nut I, which. rests upon the
upper extremity of the rod G. The screws H of tho pair of side rods G aro
fastened to the clevator bar F by a pin, which is passed through an eye on the
under side of the bar F.
In the modifications shown in my illustrative Drawings there aro three eyes
on the under side of the bar, for the convenience of shifting the screw to or
from the fulcrum of the elevator bar as required. The elevator bar is a
bar of metal, concave upon its upper side, and hinged at one extremity to tho
muzzle of the barrel, the hinged part of the bar serving as an axis, on which
it moves. The free end of the elevator bar F passos just behind the vertical
index plate J, the face of which is graduated or divided into equal parts. Tho
position of the elevator bar in relation to the index plate J serves to show the
marksman whether the object he desires to hit is within tho range of tho
weapon or not, for when the muzzló of the barrel is raised so that the bar F
stands at the highest mark on the index plate J; the gun is then elevated for
its longest range, whilst the marks on the plate below the highest serve to
show the distance of the object within the range when the gun has been duly
aimed.
.
Tho graduations upon the index plate may be made either for fathoms or
yards, according to the particular service for which the gun is required; but'
for nautical purposes the division of the scale to agree with tho distance in
fathoms would be the-most convenient. The lock of the gun is protected from
the weather and the spray of sea water by a hinged metal cover K, which is
fitted upon the upper side of the stock, and shuts the whole in.
The trigger for actuating the lock passes partially through the thick part
of the stock, as is shown by the dotted lines in my Sheet of Drawings. A
lanyard or cord L is fastened to the lower extremity of the trigger, and passed
through an aperture made for the purpose in the lower part of the stock.
This arrangement of the trigger greatly lessens the liability to accidental
discharge of the gun, as is the case when the trigger is fitted externally. The

page_text: accidental firing of the piece is also prevented by means of a metal pin,
which is passed through a holo made in the stock at the back of the
trigger.
In applying this modification of my improvements in harpoon guns to the
capture of whales, the ordinary practice is to attach the harpoon to a line of
a length equal to the range of the gun. The other end of this line, which is
technically.called a "foregoer," is bent on or fastened by a knot to another
and stouter cord or line, forming the main whale line. The "foregoer" is'
made of the finest yarns, and as pliable as possible; when not in use it is
coiled neatly and regularly into a small tub or recess at the side of the gun.
When the whale rises to the surface of the water the marksman or harpooner
can ascertain if it is within the gun's range by means of the moveable elevator
bar F, for, if upon taking aim the after end of the bar rises above the upper
mark of the scale upon the index plate J, it will be useless for him to fire, as
the object is beyond the range for which the piece is calculated; but as the
boat is rowed towards the whale the muzzle of the gun will require depressing,
and this action causes the elevator bar to descend in a proportionate degree..
When the bar has descended to the graduated scale the marksman may be
sure that the whale is within the effective range of the harpoon.
Another modification of the mechanical arrangement, by means of which
the clevator bar is caused to act simultaneously with the vertical motion of the
gun, is shown in Figure 2 of my Sheet of illustrative Drawings. In this
modification the arrangement of the stock A, the barrel B, and the swivel C
is similar to the gun shown in Figure 1. The tail picce E is also like that in
Figure 1; but instead of being connected directly to the side rods, it is attached
thereto by an intermediate lever F. This lever is secured to the tail piece E
and the side rods G by nuts and bolts, and it is fitted inside the tail piece E,
its front end extending towards the swivel C. The free end of the lever F
presses against a grooved roller H, which is capable of adjustment in a hori-
zontal direction, so as to regulate the angle of the intermediate lever. A
metal plate I is screwed to the side of the stock A; this plate carries a looso
horizontal screw J; on this screw is a nut, which may be traversed from end
to end of the horizontal screw. A stud projects from the face of the nut,
which stud carries the grooved roller H, and according to the position of
the roller upon the screw J the angle of the intermediate lever will be
varied. The side rods G are connected to the elevator bar K by means of an
adjustable screw attachment, similar to that before described in reference to
Figure 1 of my Sheet of illustrative Drawings. In this mode of adjusting the
elevator bar, the immediate lever F presses against the edge of the grooved
:

page_text: roller H; and serves to raise or depress the side rods as the stock of the gun is
elevated or depressed, the elevator bar rising or falling in accordance with the
motion of the side rods.
When fitted with either of the modifications herein-before described the
harpoon gun is rendered a far more effective weapon and much easier to use
than when made with the ordinary fixed elevator bar. These arrangements
of the elevator bar may also be applied with advantage to guns used for firing
lances or other similar missiles, in order to insure greater accuracy in firing..
than has hitherto been obtained.
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 carriod
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had 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 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, as herein-
before described.
'Second, the use and application to guns used for firing harpoons, lances,
and other similar projectiles of a moveable elevator bar and a graduated index
plate, as herein-before dscribed.
Third, the mechanical arrangements for adjusting the elevator bar and
causing it to move in accordance with the vertical motion of the gun, as
herein-before described.
In witness whereof, I, the said Alexander Mitchell, have hereunto set
my hand and seal, this Twentieth day of August, One thousand eight:
hundred and fifty-seven.
ALEXANDER MITCHELL. (L.S.)
ALEXANDER MITCHELL. (L.B.)