IMPROVEMENTS IN PROJECTILES FOR ORDNANCE AND OTHER FIRE-ARMS.
Year: 1855

page_text: LETTERS PATENT to Thomas Walker, of Birmingham, in the County of
Warwick, Engineer, for the Invention of "IMPROVEMENTS IN PROJECTILES
FOR ORDNANCE AND OTHER FIRE-ARMS.".
PROVISIONAL SPECIFICATION left by the said Thomas Walker at the
Office of the Commissioners of Patents, with his Petition, on the
23rd June 1855.
I, THOMAS WALKER, of Birmingham, in the County of Warwick, Engineer,
5 do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
PROJECTILES FOR ORDNANCE AND OTHER FIRE-ARMS" to be as follows:-
My improvements relate to forming projectiles which are of a cylindrical
figure, or partly so, with grooves or flutes lengthwise of but slightly inclined
across their cylindrical surface, for the purpose of giving to such projectiles a
tendency to rotate as they pass through the air. I would state that. I am
aware it is not new generally to apply wings or vanes to projectiles with a
view to give them a rotary motion, as various propositions have heretofore been
made, and with that object. And my improvements consist in forming such
grooves or flutes that the inclination given them may have relation to the
opening or distance between the edges of such grooves or flutes, & whatever
that distance may be, the inclination of the grooves or flutes should not exceed
it;..and I prefer that the cylindrical surface of such projectiles be covered
with such grooves or flutes. The ends of the grooves furthest from the

page_text: direction of motion of the projectile will be either closed by the metal of which
the projectile is composed, or by the application thereto of a "sabot," or other
carrier or wad, for the purpose of closing the passage to the grooves, and
preventing windage while in the barrel.
Also, the improvements relate to giving rotary motion to projectiles when
fired from ordnance or fire-arms, by, the application thereto of a charge or
charges of gunpowder, or gunpowder and other matters, such as employed in
catherine wheels, & other fireworks where motive power is obtained by the
discharge of such composition of gunpowder, and applied so as to give the
rotary motion desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Walker, in the Great Seal Patent Office on the
22nd December 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WALKER, of Birmingham, in the County of Warwick, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of June, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me; the
said Thoinas Walker, Her special licence that I, the said Thomas Walker, my
executors, administrators, and assigns, or such others as I, the said Thomas
Walker, 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
POR ORDNANCE AND OTHER FIRE-ARMS," upon-the-condition (amongst others) that
I, the said Thomas Walker, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, 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 Thomas Walker, 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):

page_text: My improvements relate, first, to forming projectiles which are of a
cylindrical figure, or partly so, with grooves or flutes lengthwise of but slightly
inclined across their cylindrical surface, for the purpose of giving to such pro-
jectiles a tendency to rotate as they pass through the air. I would state that
I am aware it is not new generally to apply wings or vanes to projectiles with
a view to give them a rotary motion, as various propositions have heretofore
been made, and with that object. And my improvements consist in forming
such grooves or flutes that the inclination given them may have relation to
the opening or distance between the edges of such grooves or flutes, and
whatever that distance may be, the inclination of the grooves or flutes should
not exceed it; and I prefer that the cylindrical surface of such projectiles be
covered with such grooves or flutes. The ends of the grooves furthest from
the direction of motion of the projectile will be either closed by the metal of
which the projectile is composed, or by the application thereto of a "sabot," or
other carrier or wad, for the purpose of closing the passage to the grooves, and
preventing windage while in the barrel...
Secondly, the improvements relate to giving rotary motion to projectiles when
fired from ordnance or other fire-arms, by the application thereto of a charge
or charges of gunpowder, or gunpowder and other matters, such as employed
in catherine wheels, and other fireworks where motive power is obtained by
the discharge of such composition of gunpowder, and applied so as to give the
rotary motion desired.
But that the nature of my Invention may be fully understood and readily
carried into effect, I will proceed more fully to describe the means pursued
by me...
: Figure. 1. shows an external side view, Figure 2 a longitudinal section;
Figure 3a front end view, and Figure 4 a back view, of a projectile con-
structed according to the first part of my Invention. a, a, represent the
grooves or flutes, inclined, according to my improvements, somewhat across
the surface of the projectile; and. I would here repeat what I have already
stated, I am aware that projectiles have already been produced with flutes,
projections, or. blades to act as wings, with the object of giving to them a
rotary motion in their. passage through the air when fired from smooth-bored
or uprifled ordnance or other fire-arms; but, to the best of my belief, all
arrangements of the kind have hitherto failed to accomplish that object; and
from the experiments which I have made, I have discovered that the cause
of failure has in most part arisen from the want of a proper relation being
preserved between the amount of inclination given to the grooves or recesses
along the projectilé, and. the distance between the edges or outer surface of

page_text: each. of such grooves or flutes; and I have found that whatever the distance
may be between such edges or outer surfaces, the inclination in the length of
each groove or flute should not exceed that distance; and I prefer that it be
about one half that distance, whereby in looking along such grooves in a line'
parallel to the axis of the projectile at a few yards' distance, the whole length
of one side of each of such grooves will be seen. The lines a¹, a', 'represent the
edges or outer surfaces of the inclined grooves or flutes a; and supposing the
line b to represent a vertical line parallel to the axis of the projectile, it will be
seen that whilst that line passes through the lower end of the edge or outer
surface a¹ of one groove or flute, the upper end of that edge is inclined from
the vertical line a distance somewhat about one half of that between the edges
of each of such grooves or flutes. I would, however, state that I do not con-
fine myself to the amount of inclination shown, even with projectiles whose
cylindrical surface are of the same length in relation to their diameter, so long
as whatever the length of groove or flute along the surface of such projectiles,
the amount of inclination given thereto, shall not exceed the distance between
the outer edges or surfaces of such grooves or flutes. And by such relation
being preserved in respect of such grooves or flutes, I have found that the air,
by acting along one side or surface of each groove or flute, has an effect upon
the surface of the projectile to give a rotary motion thereto in its passage
through the air without obstructing its motion, as has been found to be the
case when the inclination of the grooves has exceeded that here stated. The
ends of the grooves or flutes furthest from the direction of motion of the pro-
jectile are closed by a rim c to prevent windage; but in place of such rim a
"sabot," or other carrier or wad, may be employed. I form such projectiles
with a recess or hollow at the end farthest from the direction of their motion
when fired, in order to lighten that end, and throw the centre of gravity thereto
forwards.
In carrying out the second part of the improvements, I drill or otherwise
form holes in the lower end of the projectiles in the direction of the length
thereof, but inclined in a similar direction to the flutes or grooves a, as shewn
by the red dotted lines, and I fill such recesses with gunpowder, or gunpowder
in combination with other matters, such as employed in the manufacture of
catherine wheels, and other fireworks-where motive power is obtained by the
discharge thereof, in order that when such matters are ignited by the discharge
of the projectile, and consequent ignition of the quick match thereto, rotary
motion, as also additional propulsive power, may be given to the projectile
during its flight.
Having thus described the nature of my said Invention, and the means

page_text: which I adopt of carrying the same into effect, I would have it understood
that I do not confine myself to the precise details shewn so long as the peculiar
character of my Invention be retained; but what I do claim is,-
First, the forming projectiles for ordnance and other fire-arms with grooves
or flutes thereon inclined, in the relation explained.
And, secondly, I claim for giving to projectiles rotary motion by the appli-
cation thereto of the matters as explained.
In witness whereof, I, the said Thomas Walker, have hereunto set my
hand and seal, this Twenty-second day of December, in the year of our
Lord One thousand eight hundred and fifty-five.
Witness,
WILLIAM BROOKES,
73, Chancery Lane, London,
Patent Agent.
THOS WALKER. (L.S.)