MODES OF AND MACHINERY AND ACCESSORY APPARATUS FOR WORKING WAR TURRETS AND HEAVY ORDNANCE
Year: 1868

page_text: LETTERS PATENT to John McFarlane Gray, of Birkenhead, in the
IMPROVED
County of Chester, Engineer, for the Invention of
MODES OF AND MACHINERY AND ACCESSORY APPARATUS FOR WORKING WAR
TURRETS AND HEAVY ORDNANCE."
Sealed the 6th April 1869, and dated the 8th October 1868.
PROVISIONAL SPECIFICATION left by the said John M°Farlane Gray
at the Office of the Commissioners of Patents, with his Petition,
on the 8th October 1868.
I, JOHN MCFARLANE GRAY, of Birkenhead, in the County of Chester,
Engineer, do hereby declare the nature of the said Invention for "IM-
PROVED MODES OF AND MACHINERY AND ACCESSORY APPARATUS FOR WORKING WAR
TORRETS AND HEAVY ORDNANCE," to be as follows:--
I work revolving war turrets by steam power machinery under the
direct control of and operated by the person who is pointing the
guns.
According to one mode of working, this person is stationed in the
turret and moves with it; according to another mode the person who

page_text: is directing the motions of the turret and pointing the guns is stationed
at a look-out place at some distance from the turret, and from that
station he operates an engine which revolves the turret, and at the same
time he points the guns by aiming with a sight which is maintained in
a direction at all times parallel with the guns in the turret.
The part of my Invention referring to improved machinery and
accessory apparatus consists of various methods of applying a "steering
engine" to work war turrets and heavy ordnance, and includes special
accessory contrivances, details, and arrangements used in carrying out
the Invention.
By the improved machinery I render the improved modes of working
practicable; but these improvements are also applicable where these
modes of working are not strictly adhered to.
The steering engine I prefer is described by me in the Specification of
a Patent granted to me on the 18th December 1866, and numbered 3321.
Several forms of the steering engine are there given, but I use that form
in which the connecting medium is a revolving shaft.
According to one arrangement I revolve a turret by a steering engine
placed in any suitable position, say on the deck below the turret, and
connected by gearing to the turning gear of the turret. In turrets with
an open unobstructed centre the shafting is led from the controlling
or starting wheel vertically down the centre of the turret, the controlling
wheel being in the turret and the differential starting apparatus on the
engine. The controlling wheel is on a horizontal shaft, and a bevel
pinion on this shaft gears with another bevel pinion on the upper end
of the vertical shaft which connects to another horizontal shaft at its
lower end by a pair of bevel pinions, and this horizontal shaft is con-
tinued to the differential apparatus on the engine. I prefer that the
two horizontal shafts shall revolve at the same speed, turn for turn,
and to effect this it is necessary that the gearing connecting them should
be so proportioned that if the turret did not revolve the lower horizontal
shaft should make one turn more than the upper one, while the con-
trolling wheel makes the number of turns necessary to cause the turret
to make one revolution when the motion of the turret is intended to be
in the same direction as the upper side of the controlling wheel, and one
turn less if the motion of the turret is intended to be in the opposite
direction to the motion of the upper side of the controlling wheel; this
is to neutralize the motion of the turret which carries the controlling

page_text: wheel and its shaft, while the horizontal shaft below is stationary in the
ship. In this arrangement the vertical shaft leading to the stop valve
must be central in the turret. In turrets with an open centre containing
a column or other partial obstruction the controlling wheel is on a
horizontal shaft in the turret as before; on this shaft there is also a
small bevel pinion gearing with an annular bevel wheel, that is, a bevel
wheel which has merely a rim with teeth on it. This rim is turned to
fit a turned scat which is also annular; this seat is fixed in the turret
and is central with it, and when the controlling wheel is revolved this
annular bevel wheel travels round on its seat. But on one side of this
annular wheel, on the inside of the rim, there are a few teeth which
gear with a toothed quadrant lever upon the top of a small vertical shaft
supported on the stationary centreing of the turret, and placed at one
side of the opening through the centre of the turret; this vertical shaft
does not revolve, it only vibrates through a certain angle to one side or
to the other. A lever on the lower end of this shaft is connected to the
stop valve of the steering engine by suitable rods, but without the inter-
vention of the differential screw; the annular bevel wheel becomes in
this arrangement the differential gear. When the controlling wheel is
moved, the turret being at rest, the annular wheel is moved, but that,
by the inner teeth upon it, thereby moves the vertical shaft, and the
stop valve is moved from its middle position, and the engine starts to
work the turret in a direction the opposite to the motion imparted to the
annular wheel, and the speed of the engine will increase until the turret
is moved at the speed which corresponds with the rate at which the
steersman is revolving the controlling wheel, and then the small bevel
pinion on the controlling shaft will simply roll on the periphery of the
annular wheel without moving it in relation to the ship, although it will
appear to move in relation to the turret. This annular wheel arrange-
ment takes the place of the differential screw in the steering engine of
my former Patent, and thereby adapts the steering engine to be worked
as described, although there should be a stationary column or other
obstruction in the centre of the turret. In turrets having a solid centre
or footstep I use a controlling wheel and its shaft and bevel pinion as
in the arrangement last described, but this pinion gears directly with a
pinion on the upper end of a vertical shaft which passes through the
floor of the turret and is carried with the turret. On the lower end of
this shaft there is a small spur pinion gearing with an annular spur
wheel which encircles the footstep but is free of it. This annular wheel

page_text: is central with the turret, and is carried on a turned seat fixed on the
deck of the ship. To the lower side of this annular wheel is attached a
rod leading to the stop valve of the engine, and the action of this
annular wheel is virtually the same as that of the annular bevel wheel
described in the last arrangement. This annular wheel is placed between
the floor of the turret and the deck.
Note. The last two arrangements are also possible arrangements for
turrets with clear open centres. The annular wheel as a possible
arrangement may be made to act upon a differential apparatus at the
engine by a revolving shaft. To effect this the gearing must be so pro-
portioned that the annular wheel has some motion relatively to the ship
when the turret is moving at the desired speed. I also work turrets
from a controlling wheel placed in a conning tower at a distance from
the turret. In the conning tower I arrange revolving sights to be
always parallel with the position of the guns in the turret when the
turret is at rest. The aim for the guns is taken by these sights which
are worked by the shaft of the controlling wheel, and the steering engine
brings the guns into the parallel position. Allowance for the distance
between the conning tower and the turret can be made in taking aim,
and orders can be transmitted from the conning tower to the turret by a
suitable telegraph; but I prefer firing the guns by electricity by a wire
from the conning tower. The sights in the conning tower should be
always two sights side by side on the same vertical shaft, but far
enough apart to allow of dead spaces in the sides of the conning tower,
so that when one sight is obstructed the other is open. These sights
are on feather keys on a light telescopic shaft so arranged that they can
be elevated to the level of the look-out openings or depressed below
them as required. There is a graduated table round this shaft stationary
in the tower and a pointer on the shaft, so that the guns can be brought
nearly to bear without elevating the sights to the look-out holes. To
facilitate approximate aiming after the truc aim has once been arrived
at, as when aiming becomes imperfect from smoke or from other causes,
the vessel carrying the turret being nearly stationary, but turning about
to some extent, I attach around the fixed graduated circle another circle
divided as a compass card, but with the bearings in the reverse order.
In the conning tower there is a common steering compass, and
when aim is known the reverse compass circle is turned to bring the
bearing of the ship at that instant to correspond with the point of aim

page_text: on the graduated circle. To repeat the same aim by approximation
or in the dark the sights are brought not to a point noted on the
graduated scale, but to the point on the reverse compass circle cor-
responding with what is now the true bearing of the ship. By this
plan the point of aim does not require to be noted after the reverse
compass circle has been turned to the bearing of the ship, and it is
not necessary to remember what was the bearing, for the steering compass
itself is the tell-tale to be looked at. These sights are made removeable,
so that if injured one set can be lifted out and another put in in an
instant as there is no fixing required.
I have now described the modes of working turrets from within the
turret and from without from a conning tower by a steering engine. I
may add that the two plans may be applied to the same turret with one
engine if required.
Another part of my Invention relates to the working of the guns in
the turret. I do this by the same engine. In a turret with two guns I
have a horizontal shaft situated between, under, and parallel to the
guns; this shaft projects through the side of the turret and carries a
spur pinion on its outer end. This shaft in the turret carries a short
endless screw or worm, and gears into a worm wheel on a horizontal
shaft lying crossways in the turret; this cross shaft carries two chain
wheels, one for each gun, and two endless chains, one for each gun, pass
over these and over other chain wheels below the other ends of the guns.
The chain wheels on the cross shaft are carried upon friction centres or
compressors, or are fixed upon the shaft and attached by friction com-
pressors to the gun carriage. The gearing for revolving the turret is at
one side of the turret where it is best protected and where it is most
convenient to load the guns. The turret is revolved after each discharge
to bring the guns in a line with this. gearing, and then the spur pinion
upon the end of the first horizontal shaft is in gear with a wheel on the
shaft for revolving the turret. By a clutch the pinion for revolving the
turret is made loose in relation to this wheel, and when the engine now
rotates the turret does not revolve, but the horizontal shaft in the turret
revolves and drives the worm wheel on the cross shaft in one direction or
the other as required. The friction connections are either slackened, or
tightened, or over-run, as is most convenient for working the gun
carriages on end. When the guns are loaded and brought forward to
their proper position the clutch is moved and the turret-turning pinion

page_text: is again fast, and when the engine moves the turret revolves and carries
the pinion on the worm shaft out of gear with the wheel which was
driving it. When working the gun carriages the engine does not work
with differential starting gear. By this arrangement I adapt the
steering engine to revolve a turret or to work the gun carriages in the
turret under the control of one man in the turret. When the turret is
controlled from the conning tower there is a controlling wheel also at
the gearing outside of the turret, and the turret can be worked either
from the conning tower or from this wheel. When working the gun
carriages a man at this wheel controls the engine. The small shaft
between the conning tower becomes a telegraph between these two men,
and communication can be made from one to the other by turning the
shafting. When from the conning tower the turret has been brought
round to loading position, the man at the turret can take charge of the
wheel, and without taking the controlling shafting out of gear can work
the gun carriages. The wheel in the conning tower will make move-
ments of small range while this is going on, which will be understood in
the conning tower. When the guns are ready the man at the turret
gearing will connect the turning gear and move round the turret more
than a whole turn of the controlling wheel; this is the signal to the
conning tower, and the steersman there at once takes charge of the wheel.
The vertical shaft carrying the sights in the conning tower is driven from
a fork or double arm on a wheel loose on this shaft; the sides of this
fork have adjustable drivers, and between these is an arm fast on the
shaft. Between the drivers there is just so much play that the sights
fall behind the motion of the controlling wheel to such an extent as
corresponds to the ascertained amount of play and twist in the con-
trolling shafting. The greater the number of turns of the controlling
wheel is made for one revolution of the turret the greater will be the
accuracy of the parallel aiming. When the ordnance consists of one
large piece placed in a stationary tower with port holes I work the gun
carriage by a single crank arm on a vertical shaft through the floor of
the tower. The crank is horizontal and carries a vertical crank pin;
on this crank pin there is an oblong block which slides freely between
slide bars on the frame of the gun carriage. At each port there is a
strong pin, and a coupling piece connects the gun carriage to the pin,
which thus becomes the training centre or fighting pin. By moving
the crank to one side or the other the gun is trained to any required
angle about this pin. The working of the gun out or in upon the

page_text: carriage frame is effected also by the motions of the horizontal crank.
Upon the gun carriage I have a pair of chain wheels, one at each end
of the carriage, and over and under these I carry a chain; the ends of
this chain are fastened to the crank pin block. The chain wheel at the
rear of the gun carriage has two ratchet wheels, one at each side of it,
all on the same spindle; these ratchet wheels form the sides of a friction
centre for that chain wheel. One of the ratchet wheels has its teeth
inclined in one dirction and the other in the opposite direction, and a
pall for each is hinged on the gun carriage. The chain wheel at the
fore end is simply mounted on gudgeons.
I will now describe the action of these parts:-If neither of the palls
is in gear, then the longitudinal motions of the crank pin block will, by
motion of the chain, merely cause the chain wheels to revolve and will
not move the carriage; but if one of the palls is in gear, then the crank
pin in moving the chain in one direction will move the gun carriage,
and in the opposite direction the pall will have no hold, and the chain
wheels will revolve as before without moving the carriage. When the
other pall is in gear the motion will be in the opposite direction. The
moving of the guns from port to port is effected also by the central
crank. For this purpose I make an arm on the same crank boss opposite
to the one carrying the crank pin;. I make a provision on the end of
this arm for couplings to the gun carriage frame when it is central with
the crank, and when coupled I undo the coupling on the training centre,
and now any movement of the crank carries the gun carriage frame, gun
carriage, and gun with it. The crank is moved until the gun is brought
opposite the required port, and the hinge is then hooked on to that
training pin, the crank arm coupling is undone, and the gun can then
be worked at this port. The gun carriage frame is upon wheels with
transverse sweeps on the deck. The fore wheels are beyond the extremity
of the crank arm, and the hind wheels pass clear of the crank. The
crank which effects these movements is itself worked by suitable gearing
below the deck. I prefer to drive the gearing by a steering engine.
The controlling wheel for this engine is at one side of the tower clear of
the sweep of the gun carriage; this can be worked by a man at the
wheel according to orders from the person pointing the gun, or it can
be worked by the person aiming the gun, which is the method I prefer.
I accomplish this by leading an endless rope over the controlling wheel,
with a guide case over it to keep it always on the wheel. The free
double of this rope is led to the rear of the gun carriage, and by it the

page_text: gun can be worked by the person taking aim. The wheels of the gun
carriage frame I make of discs, making up of, say, four discs one wheel,
which is not conical in outline. The discs being free to revolve inde-
pendantly reduce the amount of twisting action produced by parallel
training wheels. The training races are made flat sweeps.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John M Farlane Gray in the Great Seal Patent
Office on the 8th April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MCFARLANE GRAY, of Birkenhead, in the County of Chester, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of October, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John McFarlane Gray, Her special
license that I, the said John M°Farlane Gray, my executors, adminis-
trators, and assigns, or such others as I, the said John McFarlane
Gray, my executors, administrators, and 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 Inven-
tion for "IMPROVED MODES OF AND MACHINERY AND ACCESSORY APPARATUS
FOR WORKING WAR TURRETS AND HEAVY ORDNANCE," upon the condition
(amongst others) that I, the said John McFarlane Gray, 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 John McFarlane Gray, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
I work revolving war turrets by steam power machinery under the
direct control of and operated by the person who is pointing the guns.
According to one mode of working, this person is stationed in the
turret and moves with it; according to another mode the person who is
directing the motion of the turret and pointing the guns is stationed at
a look-out place at some distance from the turret, and from that station
he operates an engine which revolves the turret, and at the same time
he points the guns by aiming with a sight which is maintained in a
direction at all times parallel with the guns in the turret.
The part of my Invention referring to improved machinery and
accessory apparatus consists of various methods of applying a "steering
engine" to work war turrets and heavy ordnance, and includes special
accessory contrivances, details, and arrangements used in carrying out
the Invention.
By the improved machinery I render the improved modes of working
practicable; but these improvements are also applicable where these
modes of working are not strictly adhered to.
The steering engine I prefer is described by me in the Specification
of a Patent granted to me on the 18th December 1866, and numbered
3321. Several forms of the steering engine are there given, which are
all more or less applicable to the purposes of the present Invention, but
I prefer that form in which the connecting medium is a revolving shaft
as applied by me to steer the "Great Eastern," and to simplify this
Specification I will describe my present Invention as carried out with
only that form of steering engine.
According to one arrangement I revolve a turret by a steering engine
placed in any suitable position, say on the deck below the turret, and
connected by gearing to the turning gear of the turret. In turrets with
an open unobstructed centre shafting is led from the controlling or
starting wheel vertically down the centre of the turret, the controlling
wheel being in the turret and the differential starting apparatus on the
engine. The controlling wheel is on a horizontal shaft, and a bevel
pinion on this shaft gears with another bevel pinion on the upper end
of the vertical shaft which connects to another horizontal shaft at its
lower end by a pair of bevel pinions, and this horizontal shaft is
continued to the differential apparatus on the engine. I prefer that the

page_text: two horizontal shafts shall revolve at the same speed, turn for turn, and
to effect this it is necessary that the gearing connecting them should
be so proportioned that if the turret did not revolve the lower horizontal
shaft should make one turn more than the upper one, while the
controlling wheel makes the number of turns necessary to cause the
turret to make one revolution when the motion of the turret is intended
to be in the same direction as the upper side of the controlling wheel, and
one turn less if the motion of the turret is intended to be in the opposite
direction to the motion of the upper side of the controlling wheel;
this is to neutralize the motion of the turret which carries the con-
trolling wheel and its shaft, while the horizontal shaft below is
stationary in the ship. In this arrangement the vertical shaft leading
to the stop valve must be central in the turret. In turrets with an
open centre containing a column or other partial obstruction the
controlling wheel is on a horizontal shaft in the turret as before; on
this shaft there is also a small bevel pinion gearing with an annular
bevel wheel, that is, a bevel wheel which has merely a rim with teeth
on it.
This rim is turned to fit a turned seat which is also annular; the
said seat is fixed in the turret and is central with it, and when the
controlling wheel is revolved this annular bevel wheel travels round on
its seat. But on one side of this annular wheel, on the inside of the
rim, there are a few teeth which gear with a toothed quadrant lever
upon the top of a small vertical shaft supported on the stationary
centreing of the turret, and placed at one side of the opening through
the centre of the turret; this vertical shaft does not revolve, it only
vibrates through a certain angle to one side or to the other. A lever
on the lower end of this shaft is connected to the stop valve of the
steering engine by suitable rods, but without the intervention of the
differential screw; the annular bevel wheel becomes in this arrangement
the differential gear. When the controlling wheel is moved, the turret
being at rest, the annular wheel is moved, but that, by the inner teeth
upon it, thereby moves the vertical shaft, and the stop valve is moved
from its middle postion, and the engine starts to work the turret in a
direction the opposite of the motion imparted to the annular wheel, and
the speed of the engine will increase until the turret is moved at the
speed which corresponds with the rate at which the steersman is revolving
the controlling wheel, and then the small bevel pinion on the controlling
shaft will simply roll on the periphery of the annular wheel without
moving it in relation to the ship, although it will appear to move in

page_text: relation to the turret. This annular wheel arrangement takes the place
of the differential screw in the steering engine of my former Patent, and
thereby adapts the steering engine to be worked as described, although
there should be a stationary column or other obstruction in the centre
of the turret. In turrets having a solid centre or footstep I use a
controlling wheel and its shaft and bevel pinion as in the arrangement
last described, but this pinion gears directly with a pinion on the upper
end of a vertical shaft which passes through the floor of the turret and
is carried with the turret. On the lower end of this shaft there is a
small spur pinion gearing with an annular spur wheel which encircles
the footstep but is free of it. This annular wheel is central with the
turret, and is carried on a turned seat fixed on the deck of the ship.
To the lower side of this annular wheel is attached a rod leading to
the stop valve of the engine, and the action of this annular wheel is
virtually the same as that of the annular bevel wheel described in the
last arrangement. This annular wheel is placed between the floor
of the turret and the deck.
Note. These last two arrangements are also possible arrangements
for turrets with clear open centres. The annular wheel as a possible
arrangement may be made to act upon a differential apparatus at the
engine by a revolving shaft. To effect this the gearing must be so
proportioned that the annular wheel has some motion relatively to the
ship when the turret is moving at the desired speed. I also work turrets
from a controlling wheel placed in a conning tower at a distance from
the turret. In the conning tower I arrange revolving sights to be
always parallel with the position of the guns in the turret when the
turret is at rest. The aim for the guns is taken by these sights, which
are worked by the shaft of the controlling wheel, and the steering engine
brings the guns into the parallel position. Allowance for the distance
between the conning tower and the turret can be made in taking aim,
and orders can be transmitted from the conning tower to the turret by
a suitable telegraph; but I prefer firing the guns by electricity by a
wire from the conning tower. The sights in the conning tower should
be always two sights side by side on the same vertical shaft, but far
enough apart to allow of dead spaces in the sides of the conning tower,
so that when one sight is obstructed the other is open. These sights are
on feather keys on a light telescopic shaft, so arranged that they can be
elevated to the level of the look-out openings or depressed below them
as required.
There is a graduated table round this shaft stationary

page_text: in the tower and a pointer on the shaft, so that the guns can be
brought nearly to bear without elevating the sights to the look-out
holes. To facilitate approximate aiming after the true aim has once
been arrived at, as when aiming becomes imperfect from smoke or from
other causes, the vessel carrying the turret being nearly stationary, but
turning about to some extent, I attach around the fixed graduated circle
another circle divided as a compass card, but with the bearings in the
reverse order. In the conning tower there is a common steering
compass, and when aim is known the reverse compass circle is turned
to bring the bearing of the ship at that instant to correspond with the
point of aim upon the graduated circle. To repeat the same aim by
approximation or in the dark the sights are brought not to a point noted
on the graduated scale, but to the point on the reverse compass circle
corresponding with what is now the true bearing of the ship. By this
plan the point of aim does not require to be noted after the reverse
compass circle has been turned to the bearing of the ship, and it is not
necessary to remember what was the bearing, for the steering compass
itself is the tell-tale to be looked at. These sights are made removeable,
so that if injured one set can be lifted out and another put in in an
instant as there is no fixing required.
I have now described the modes of working turrets from within the
turret and from without from a conning tower by a steering engine.
I I may add that the two plans may be applied to the same turret with
one engine if required.
Another part of my Invention relates to the working of the guns in
the turret. I do this by the same engine. In a turret with two guns
I have a horizontal shaft situated between, under, and parallel to the
guns; this shaft projects through the side of the turret, and carries a
spur pinion on its outer end. This shaft in the turret carries a short
endless screw or worm, and gears into a worm wheel on a horizontal
shaft lying crossways in the turret; this cross shaft carries two chain
wheels, one for each gun, and two endless chains, one for each gun,
pass over these and over other chain wheels below the other ends of the
guns. The chain wheels on the cross shaft are carried upon friction
centres or compressers, or are fixed upon the shaft and attached by
friction compressors to the gun carriage. The gearing for revolving
the turret is at one side of the turret where it is best protected and
where it is most convenient to load the guns. The turret is revolved

page_text: after each discharge to bring the guns in a line with this gearing, and
then the spur pinion upon the end of the first horizontal shaft is
in gear with a wheel on the shaft for revolving the turret. To prevent
the jamming of these two wheels if they do not meet fair I leave the
outer end of the horizontal shaft free to rise to some extent in its
bearing so that it cannot rise until the teeth are fair for gearing, and the
weight of the shaft and pinion is sufficient to keep the turret in gear.
By a clutch the pinion for revolving the turret is made loose in relation
to this wheel, and when the engine now rotates the turret does not
revolve, but the horizontal shaft in the turret revolves and drives the
worm wheel on the cross shaft in one direction or the other as required.
The friction connections are either slackened, or tightened or over-run, as
is most convenient for working the gun carriages on end. When the
guns are loaded and brought forward to their proper position the clutch
is moored and the turret-turning pinion is again fast, and when the
engine moves the turret revolves and carries the pinion on the worm
shaft out of gear with the wheel which was driving it. When working
the gun carriages the starting gear does not act differentially. By this
arrangement I adapt the steering engine to revolve a turret or to work
the gun carriage in the turret under the control of one man in the
turret. When the turret is controlled from the conning tower there is
a controlling wheel also at the gearing outside of the turret, and the
turret can be worked either from the conning tower or from the wheel.
When working the gun carriages a man at this wheel controls the
engine. The small shaft between the conning tower and the gearing at
the turret becomes a telegraph between these two men, and com-
munication can be made from one to the other by turning the shafting.
When from the conning tower the turret has been brought round to
loading position the man at the turret can take charge of the wheel, and
without taking the controlling shafting out of gear can work the gun
carriages. The wheel in the conning tower will make movements of
small range while this is going on, which will be understood in the
conning tower. When the guns are ready the man at the turret gearing
will connect the turning gear, and move round the turret more than
a whole turn of the controlling wheel; this would be the signal to
the conning tower, and the steersman there would at once take charge
of the wheel. The vertical shaft carrying the sights in the conning
tower is driven from a fork or double arm on a wheel loose on this shaft ;
the sides of this fork have adjustable drivers, and between these is an

page_text: arm fast on the shaft. Between the drivers there is just so much play
that the sights fall behind the motion of the controlling wheel to such
an extent as corresponds to the ascertained amount of play and twist
in the controlling shafting. The greater the number of turns of the
controlling wheel made for one revolution of the turret the greater will
be the accuracy of the parallel aiming. When the ordnance consists of
one large piece placed in a stationary tower with port holes I work the
gun carriage by a single crank arm on a vertical shaft through the floor
of the tower. The crank is horizontal and carries a vertical crank pin;
on this crank pin there is an oblong block which slides freely between
slide bars on the frame of the gun carriage. At each port there is a
strong pin, and a coupling piece connects the gun carriage to the pin,
which thus becomes the training centre or fighting pin. By moving
the crank to one side or the other the gun is trained to any required
angle about this pin. The working of the gun out or in upon the
carriage frame is effected also by the motions of the horizontal crank or
a pawl on the gun carriage which gears with a tooth on this sliding
block. The moving of the gun from port to port is effected also by the
central crank. For this purpose I make an arm on the same crank
boss opposite to the one carrying the crank pin. I make a provision
on the end of this arm for coupling to the gun carriage frame when it
is central with the crank, and when coupled I undo the coupling on
the training centre, and now any movement of the crank carries the gun
carriage frame, gun carriage, and gun with it. The crank is moved
until the gun is brought opposite the required port, and the hinge is
then hooked on to that training pin, the crank arm coupling is undone,
and the gun can then be worked at this port. The gun carriage frame
is upon wheels with traverse sweeps on the deck. The fore wheels are
beyond the extremity of the crank arm, and the hind wheels pass clear
of the crank. The crank which effects these movements is itself worked
by suitable gearing below the deck. I prefer to drive the gearing by a
steering engine. The controlling wheel for this engine is at one side of
the tower clear of the sweep of the gun carriage; this can be worked
by a man at the wheel according to orders from the person pointing the
gun, or it can be worked by the person aiming the gun, which is the
method I prefer. I accomplish this by leading an endless rope over the
controlling wheel with a guide case over it to keep it always on the
wheel. The free double of this rope is led to the rear of the gun
carriage, and by it the gun can be worked by the person taking aim.

page_text: The wheels of the gun carriage frame I make of discs, making up of,
say, four discs one wheel, which is not conical in outline. The discs
being free to revolve independantly reduce the amount of twisting action
produced by parallel training wheels. The training races are made flat
CHOODS
First. Working guns by steam power substantially as described,
the person at the gun taking aim having the direct control of the
engine.
Second. Working turrets by steam power substantially as described,
the person at the turret taking aim having the direct control of the
engine.
Third. Working turrets by steam power with parallel aiming sub-
stantially as described, the person taking aim being at a distance from
the turret, and having there the direct control of the engine.
And, fourth. Approximate aiming by graduated index circles and
correction for alterations in the direction of the ship by a tell-tale
compass card, substantially as described.
In witness whereof, I, the said John M Farlane Gray, have
hereunto set my hand and seal, this 6th day of April, in the
year of our Lord One thousand eight hundred and sixty-nine.
JOHN MCFARLANE GRAY. (L.S.)
In the presence of
RICHARD ANDREWS MOULD.