IMPROVED FEATHERING PADDLES FOR PROPELLING SHIPS OR VESSELS."
Year: 1872

page_text: LETTERS PATENT to Robert Smyth, of Glasgow, in the County of
Lanark, North Britain, Agent, for the Invention of "IMPROVED
FEATHERING PADDLES FOR PROPELLING SHIPS OR VESSELS."
PROVISIONAL SPECIFICATION left by the said Robert Smyth at the
Office of the Commissioners of Patents, with his Petition, on the
19th December 1872.
I, ROBERT SMYTH, of Glasgow, in the County of Lanark, North
Britain, Agent, do hereby declare the nature of the said Invention for
"IMPROVED FEATHERING PADDLES FOR PROPELLING SHIPS OR VESSELS," to be as
follows, that is to say :-
My said Invention has reference to and substantially consists in new
or improved modes and means of feathering the floats of paddle wheels
for the propelling of steam ships and other vessels. The main wheels
formed of their side frames or wheels in the form of discs, keyed and
stayed at the desired length of the floats apart, having the floats

page_text: oscillating between them on axes, are all constructed and ranged round
the outer rim or discs parallel to the main driving shaft of the wheel so
far much in a usual manner, either as vertical or horizontal paddle
wheels, one placed on each side of the ship, but preferably by these
improvements placed and worked horizontally within a nearly semi-
circular recess, so as to be fully immersed well down towards the keel,
having the segmental part of rather less than the half or about a third
of the wheel projecting out beyond the recess or surface line of the
ship' sside, where the floats turn or feather as they enter the "solid
water" to act on it at right angles to the line of propulsion, and again
(or continue to) feather in receding therefrom into the recess; after so
propelling and acting, which gives all the advantages of the immersed
screw propeller combined with those of, the ordinary feathering paddle
wheel. When thus placed horizontally the main shaft works in a foot-
step bearing on the lower side; and up through a water-tight stuffing
box pipe in the upper side, both of the recess in which the wheel
works, so as to be actuated by a steam or other motive-power engine or
mechanism above and within the ship; the lower and upper sides of the
recess projecting beyond it as a guard or protection to the wheel and
support for the feathering eccentric grooves or segments.
:
•
By one construction and arrangement of the new or improved
feathering mechanism each float is fulcrummed at its ends near its
outer or one edge on its centres or axles passed through journal bearings
near the outer edge of the two side wheels or discs of the propeller, with
crank arms and antifriction wheels on its crank pins at both ends, all
so that the floats are free to oscillate and feather on their vertical axles
to the path or plane of least resistance by the mere action of passing
through the water, when they are not acting on the solid water outside
the recess; that is except at the time and part where the floats are
successively carried round through the solid water outside the recess
faster than the ship, then the pulleys on the cranks at one end ofthe
floats (on the outside of the frame or disc) enter an eccentric.or. cam
groove, or act on a hollow segment fixed on the inner face of the
projecting side or segment of the recess, so as to maintain the floats at
this propelling part at right angles to the line of propulsion and motion
of the floats and wheel while forcing or displacing the solid water for
the forward propulsion of the ship, but allowing them perfect freedom
to feather again as they leave the solid water and enter the recess, where

page_text: their speed becomes less than or in the opposite direction to that of
the ship. The antifriction wheels on the cranks at the other ends of
the floats at the same time work in or over an eccentric groove or
hollow segment attached to the other inner side of the recess, so as to
steady them in the said forward propelling position; these cranks and
their acting groove or segment also answering to set and hold the floats
in their propelling position for the reverse or backing action of the
propeller and vessel.
When used as a vertical feathering paddle or propeller, one feathering
cam piece or segment only need be used, fixed on the side of a third disc
made to revolve loosely and concentrically round the main shaft, and
which when set and fixed with the cam piece in its lowest position,
would guide the pulleys of the cranks and floats for the forward pro-
pelling action, and when unlocked and turned round by the mere action
of the float cranks themselves to the upper side, where it would be
again locked by the simple insertion of a sliding bolt or other equivalent,
through the side of the recess; the cam piece would guide and maintain
the floats in the position for "backing" the wheel and vessel.
Another or second modification or construction and arrangement of
the parts of this improved feathering mechanism, consists in jointing
the end axles of each float loosely in bearings at the outer ends of two
cranks fixed on cross spindles working in journal bearings close to the
inside and outer edge of the side discs of the wheels. Each axle has a
crank on one outer end with its crank pin connected to an eccentric
disc revolving loosely on an cecentric centre or eye secured to the side
of the recess, so as to carry the outer ends of the cranks and fulcrummed
edge of the floats out beyond the wheel or recess into the solid water at
the part where the floats are required to act at right angles to and on the
water at a greater velocity than that of the ship, so as to propel it.
The floats at every other part when not driven through the water at the
velocity of the ship as when entering and receding from the solid water,
and when passing round the recess in the opposite direction to the
motion of the vessel, are free to find their path or line of least resist-
ance; but as soon as they pass out of the recess into the solid water for
propelling the vessel in either direction at a greater speed than the ship,
then the pressure on the water immediately turns the floats against the
cross axles of the cranks or other equivalent stops, so as to maintain
them at right angles to the line of propulsion, but leaves them free to

page_text: recede from the said axle or stops as soon as they cease to have any
propelling effect. By both these improved arrangements of feathering
mechanism the floats are made to act and propel at the best possible
angle to the line of propulsion, and at the only time when they can
have power, namely, when their speed is greater than that of the ship
in the opposite direction, while, the moment this ceases to be the case,
they are free to turn and feather to the path of least resistance at every
other part of the revolution of the propeller while they are coming round
to the acting position again.
One great advantage of this improved propeller when used as a
horizontal paddle wheel, one on each side, is its steadying power over
the vessel while being completely submerged; it is most suitable for
war and other sea-going ships, being quite out of the way of an
enemy's shot or shell, and the dangerous action of surface waves and
breakers.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Smyth in the Great Seal Patent Office on
the 16th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
SMYTH, of Glasgow, in the County of Lanark, North Britain, Agent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of December, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Robert Smyth, Her special licence that I, the said
Robert Smyth, my executors, administrators, and assigns, or such others
as I, the said Robert Smyth, 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 "IMPROVED FEATHERING PADDLES FOR PROPELLING
SHIPS OR VESSELS," upon the condition (amongst others) that I, the said

page_text: Robert Smyth, 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 Robert Smyth, 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 accom-
panying Sheet of Drawings, and to the letters and figures marked
thereon, that is to say :-
My said Invention has reference to and substantially consists in new
or improved modes and means of feathering the floats of paddle wheels
for the propelling of steam ships and other vessels. The main wheels
are formed each with their side frames or wheels in the form of discs A,
keyed and stayed at the desired distance, equivalent to the length of the
floats B apart, and these floats B are all constructed and ranged to
oscillate at equal distances apart round and between the outer rim of the
discs A parallel to the main driving shafts A¹ of the wheel, so far much
in a usual manner, either as vertical or horizontal paddle wheels one
placed on each side of the ship 1, but preferably by these improvements
placed and worked horizontally within a nearly semicircular recess 2,
so as to be fully immersed well down towards the keel, having the
segmental part of rather less than the half or about a third of the wheel
projecting out beyond the. recess 2 or surface line of the ship's
side 1", 1", where the floats B turn or feather as they enter the solid
water to act on it at right angles to the line of propulsion, and then or
again feather in receeding therefrom into the recess 2 after so propelling
and acting, thus giving all the advantages of the immersed screw
propeller combined with those of the ordinary paddle wheel. When
thus placed horizontally the main shaft A' works in a footstep bearing
4 on the lower side and up through a water-tight stuffing box pipe 5 in
the upper side, both of the recess 2 in which the wheel works so as to be
actuated by a steam or other motive-power engine or mechanism 6
above and within the ship; the lower and upper sides of the recess
project beyond it as a guard or protection 7 to the wheel and support for
the feathering eccentric grooves or segments a.

page_text: By one construction and arrangement of the new or improved
feathering mechanism, each float B is fulcrummed at its ends near its
outer or one edge B¹ on its centres or axles B" passed through journal
bearings near the outer edge of the two side wheels or discs A. of the
propeller with crank arms C at one or both ends, and lateral acting crank
pins D either with or without antifriction wheels. D' on these pins; all so
that the floats B are free to oscillate and feather on their vertical axles B"
'to the path or plane of least resistance by their mere action of passing
'through the water; when they are not passing through or acting on the
solid water outside the recess where they are required to displace the
water at a greater velocity than the ship in the opposite direction to its
motion; that is, except at the time and part a, a, where the floats are
successively carried round through the solid water (for about one-fourth
of its revolution) outside the recess 2 faster than the speed of the ship,
and where the lateral pins D of the cranks C (or the antifriction pulleys
of the floats on the outside of the main frame or discs) enter the
eccentric or cam groove a, or act on the hollow segment a' fixed on the
inner face of the projecting sides or segment 7 of the recess before referred
to, so as to maintain the floats at this propelling part 3, a, of their
revolution at right angles to the line of propulsion and motion of the
floats and wheel, while forcing or displacing the solid water for the
forward propulsion of the ship, but allowing them perfect freedom to
feather again at 3¹ as they leave the solid water and enter the recess 2
(where their speed or motion becomes less than or in a different direction
to that of the propulsion) and the pins D or their antifriction wheels D¹
of the cranks C at the other ends of the floats simultaneously work in or
over an eccentric groove a or hollow segment a³, b, attached to the other
inner side of the recess 2, so as to steady them in the said forward
propelling position; these cranks C and their acting groove or segments
a, b, also answering to set and hold the floats in their propelling position
for the reverse or backing action of the propeller and vessel by leaving
sufficient space at the entrance 3¹ of the holding eccentric guide a, b, for
the cranks C, D, to feather in the opposite direction, preferably with a
leading and guiding shifting plate c at tlie back entrance to the
7.

page_text: segment c, as in the horizontal arrangement for guiding the floats into
the holding groove for propelling in the backward direction, or it might
be with a third disc made to revolve loosely and concentrically round
the main shaft A' at the side of the ship, and set and fixed with the
eccentric or cam piece a, a, in its lowest position, to guide the pulleys D¹
of the cranks C and floats B for the forward propelling action, and when
unlocked and turned round to the upper side by the mere action of the
float cranks D themselves or otherwise, and again locked by the simple
insertion of a sliding bolt or other equivalent through the side of the
recess 2, the cam piccc a, a, would then guide and maintain the floats in
the position for "backing" the wheel and vessel without roversing the
engines.
One great advantage of this improved propeller, when used as a hori-
zontal paddle wheel, one on each side, is its steadying power over the
ship or vessel; while, being completely submerged, it is most suitable
for war and other sca going ships, being quite out of the way of an
enemy's shot or shell, and the dangerous action of surface waves and
breakers.
And in order that my said Invention, and the manner and means of
performing it may be thoroughly understood, I shall now proceed to
describe the several Figures on the Sheet of Drawings which I have
hereunto appended for the purpose of showing the best modifications
and means I am at present aware of for practically carrying the
Invention into effect or practice, the same reference letters and numerals
indicating the same or like parts in the several Figures.
Figure 1 is a bow end elevation, half in section through one of the
propellers of a steam ship 1, as fitted with a modification or construction
and arrangement of my new or improved feathering propeller, illus-
trative of my Invention applied as a horizontal propeller or wheel, one
placed and working about two-thirds within a recess 2 in cach side of
the lower part of the ship; and Figure 2 is a plan and half horizontal
section of the central part of the same ship, and arrangement of
propellers corresponding to Figure 1; while Figures 3, 4, 5, and 6, are
respectively side, edge, and end elevations, and a transverse section of
one of the propellers to a large scale, corresponding to and detached
from Figures 1 and 2, showing the construction of the feathering floats
as suitable for horizontal action and propulsion.

page_text: Figures 7 and 8 are a sectional side and half sectional bow end
elevation of a ship 1, as fitted with a construction and arrangement of
my said new or improved feathering propeller, as vertical feathering
paddles, one placed on each side of the ship as usual; and Figure 9 is a
half sectional plan of this vertical arrangement, corresponding to Figure 8,
showing only the part of the ship where the propellers are; while
Figures 10, 11, 12, and 13, are a side, edge, and end view, and a
transverse section of one of the feathering floats detached from the
arrangement shown in Figures 7, 8, and 9, and to a large scale to show
the construction for the vertical action and propulsion.
Referring to the horizontal arrangement Figures 1 and 2, each float
B is preferably formed with a strong malleable iron frame (as seen
particularly in Figures 3 to 6) formed of a strong thin cross bar B¹,
with a sharp advancing edge in line with the axial centres B" formed
on the outside of two strong thin edge pieces B* with flanges, to and
between which the wood float boards B are bolted parallel to the edge
bar B. Each axis B" has a crank C secured on it outside the main side
disc A, A, of the propeller wheels at right angles to the float B™, and
with strong lateral crank pins D in their extreme ends, projecting
outwards, so as either direct or by antifriction pulleys D¹, shown in
red lines in Figures 4 and 5, to glide or roll on the acting surfaces a¹, b¹,
of the eccentric grooves a, a, formed or secured on the outer guard
flanges 7, and the inner guides b, b, secured to the sides of the recesses
2, 2, formed in the lower part of the sides of the ship 1, 1', as seen at
Figures 1 and 2, with the starboard side and wheel A shown in
elevation, and the larboard shown in section, respectively indicated by
the letters S and L, the black arrows indicating the direction of the
ship's motion, and the blue arrows the direction of the motion of the pro-
pelling wheels A, A, when propelling "ahead," and vice versa in the
opposite direction for going "astern". In looking to the larboard wheol,
Figure 2, it will be seen that the floats feather out of the recess 2 in front,
with their sharp bar edge B' advancing into the solid water at 3, where
there is sufficient room left both in the acting eccentric surface at a" of
the outer guard guide 7, and a recess 6" in the inner guide plate b, for
all the floats and their crank pius D to thus turn and feather as their speed
or that of the ship in relation to the outer water necessitate or cause by its
action on them, but such that as soon as the speed of the propeller becomes
sufficient to cause reaction on the propelling side of each float to displace

page_text: or force the water past the side of the ship so as to propel it, then the
float B comes up (automatically by the said reaction) to the perpendicular
at right angles to the line of propulsion, where it is held by the crank
pins D acting on the inner eccentric surface a¹, a', of the guides 7, as
between the outer fourth of the revolution of the propeller, indicated
as contained within the red angled lines d, d, until the float ceases to
have any reacting or propelling effect, as at 3', 3', where the inner
and outer guides 6 and 7 are cut away at 6' and a², to allow the crank
pins D of each float. as it comes round to this part to feather out of the
solid water again through its path of least resistance at nearly a
tangential line through the fulcrum B" round the inner part of the.
recess 2, 2, in the ship's sides; this inner part 2¹ being made of a
flattish curve to give plenty of room for the paddles to move freely
out or in without striking the sides or front part at 2", but preferably
made to come close up towards the float at the outer front surface at
3", and sloped away to the run of the ship at the after side or
back 2, plenty of room being left at the upper and lower part of the
recess 2, 2, 3, for the cranks C, D, to enter and swivel in all directions.
One pair of two cylinder diagonal horizontal steam engines 6, with an
air pump and condenser between the cylinders, are shown erected on
a deck above each propeller, which is driven direct by the connecting
rods 6¹ coupled to one crank on the propeller shaft A¹; however the
propellers might be driven by any other forms or designs of horizontal
engines, either coupled or one pair of engines for both propellers, as
desired. The engines would be backed for going astern, and a shifting
segment c is preferably fitted to the back edge of the inner guide b,
at the after or back side b³, as they come round to enter the solid water
outside the recesses at 3¹, so as to guide the crank pins D in
the groove a, a, and hold them for the backing reaction and propulsion
round the face 6', 6', of the inner piece forming the side of the
groove a, a, and which also assists to steady the floats in the forward
action, although not absolutely necessary for that purpose. The
shifting segment c (which is only fitted on the top side of the recesses 2
and propellers) is actuated by a slot in it and the pin of a crank c¹
on the lower end of a vertical spindle c" working up through a
stuffing box or tube into the engine room above, with a hand shifting
and fixing lever c³, c", for setting the segment c into or out of the
backing position, as indicated in sharp and dotted red lines respectively
in TianTO 2.

page_text: •
'
Referring to my said improvements as applied to a vertical. propeller
and shown in Figures 7 to 13, the main features and construction of
the parts are the same, and the several parts are indicated by the same
letters and numerals, and the motion of the ship and propellers for
going ahead are indicated by the same black and blue arrows all respec-
tively in these Figures, as in Figures 1 to 6, heretofore described. In this
case the two vertical propelling wheels A are mounted one on each
propeller shaft A¹ just clear of the side' wall or run of the ship's side,
so that about a third or a fourth of the diameter of the wheel is immersed,
with paddle box and strong supporting frame 2, 2¹, carrying the
outer plummer block 4 of the paddle shaft A¹ passed in through the side
of the ship 1, upon inner bearing blocks and framing 5, 5¹, so as to be
actuated directly by the piston rod 6¹ of its respective cylinder of a pair
of oscillating cylinder engines 6, coupled by the intermediate crank
shaft 6". The floats B in this arrangement, as will be seen in Figures 10
to 13, have only one holding crank and pin C, D, on the side next the
ship of cach spindle B" and float bar B¹, which is made stronger (not
requiring to be thinned away as in Figures 1 and 6 to enter the water
before the float board B¹¹¹) as well as the disc or side A" of the wheel A
next the ship, to sustain the strain of the cranks C which revolve and
oscillate freely within a recess 7, a, a, formed in the side of the ship,
the outer and inner edges a¹, b', of which recess are made to form the
eccentric groove a, a, within the contained acting quarter of the revo-
tion of the floats in the water, indicated by the angled red lines d, d,
and formed preferably by the insertion of the gun metal or steel
segments a¹ and b¹ forming the outer and inner bearing surfaces for the
acting and rolling pins D or their antifriction pulleys D' indicated in
red lines in Figures 11 and 12 which, as described in reference to
Figures 1 and 2, hold the floats B at right angles to the line of propul-
sion as indicated by the black arrows and lower acting floats B in
Figure 7 from the point 3, a", 6", where the forward loose sharp edge
of the wood floats B¹¹ enter the water, to the part 3¹, a³, b³, at the back,
where the same edges feather in leaving the water, so as to take the path
of least resistance, while in the water however deep, where they have no
propelling reaction to turn the floats and cranks C up to their bearing a
and propelling position, ample space being left at 6", 3, and a³, b³, 31,
for this turning of the cranks C while the floats are feathering in
or out of the water to and from the propelling position. A curved bar
or guidez, ≈, shown in red lines in Figures 7, 8, and 9, is secured to the
,

page_text: inside of each paddle box, or otherwise, round the upper and front side
of the floats B near the side of the ship for the purpose of insuring the
steady entrance of their advance free edges into the water, and cause
them to turn inwards as they come to the acting position at 3, 6", then
for backing an oscillating segmental piece c is fitted at b², 3%, for guiding
the crank pins D into the groove a, a, so as to hold the floats in their
acting position, as stated at right angles for "backing." The segment c
being actuated by a slot and the pin of a crank c¹ on the outer
end of a spindle c" passed in through a stuffing box in the side of the
ship so as to be set and held into or out of the back acting position, as
indicated in red and dotted lines in Figure 7, by the hand lever c
and holding quadrant c™" at the inner end of the spindle, scen in Figures 7
and 9.
It will be understood that these vertical paddle wheels might when
desired be made smaller in diameter and broader or narrower, and be
immersed to greater depth, and be overhung without an outer pillow
block 4, and be worked partially or wholly within a vertical recess for
each at the lower part of the side and bottom of the ship.
By another arrangement of this holding guide the groove 7 and a, a,
with the cam parts 3, 6", and 3', a², be, gliding into these might be
formed in or on the side of a loose disc made to revolve on the axle A¹
between the inner disc A" and the side of the ship, so as to be held by a
spring slip bolt or other equivalent passed through the side of the ship
when the feathering part a, a, of the groove was at the bottom for going
ahead, and at the top part for backing; when the friction of the crank
pins D themselves would carry round the disc for this backing action, as
the engines would not require to be reversed, of this modification herein-
before referred to, and which is essentially suitable for propellers which
are deeply or wholly immersed.
Another or second modification or construction and arrangement of
the parts of this improved feathering mechanism is shown in edge
elevation and side section of a starboard vertical acting feathering paddle
wheel to a small scale in Figures 14 and 15 respectively, suitable for
very deep immersion, and also for horizontal propellers; and which, as
shown in these Figures and in Figure 16, which is a side and edge
elevation of one of the floats B detached from Figures 14 and 15,
consists in jointing the end axles e of each float B loosely on an axis or

page_text: bearings e¹ in the outer free ends of two cranks E fixed on strong cross
'spindles F working in journal bearings B₁ close to the inside and outer
edge of the side discs A, A", of the wheels. Each axle F has a crank C
fast on one end outside the wheel A, A", at right angles to the crank E,
having each their crank pins D connected to an eccentric disc G,
revolving loosely by its eye G¹ on an eccentric a (or it might be an
eccentric centre on the outside of the overhanging wheels) secured to
the side of the vessel 1 (or it might be the recess in horizontal pro-
pellers), so as to carry the cranks C out horizontally, and the ends of
the cranks E and fulcrummed edge B¹ of the floats B down and out
beyond the wheel or recess into the solid water at the part d, d, where
the floats are required to act at right angles to and on the water at a
greater velocity than that of the ship, so as to propel it. The floats B
at every other part, as at 3 and 3', when not driven through the water at
a greater velocity than that of the ship, as when they are entering and
receding from the solid water, and passing round the recess in the
opposite direction to the motion of the vessel, are free to turn on their
joints e¹, and feather or find their path or line of least resistance; but
as soon as they pass out of the recess into the solid water for propelling
the vessel in either direction, as within the lower angle d, d, at a greater
speed than the ship, then the pressure or action of the float on the
water immediately turns it up against the cross axles F of its cranks E,
or it might be other equivalent stops on these cranks, so as to maintain
the floats at right angles to the line of propulsion, but leave them free
to recede from the said axle or stops as soon as they cease to have any
propelling effect.
By both these improved arrangements of feathering mechanism,
Figures 1 to 13 and 14 to 16, the floats B are made to act and propel
at the best possible angle to the line of propulsion, and at the only time
when they can have power, namely, when their speed is greater than
that of the ship and in the opposite direction, while the moment this
ceases to be the case they are free to automatically turn or feather to
the path of least resistance at every other part of the revolution of the
propeller while they are coming round to their acting position again.
Although in all the Figures I have shown the floats B as fulcrummed
loosely at their advance or one edge B' considering this the best, yet
still it will be evident that they might be fulcrummed at any point or
line in from that some distance from their centre of gravity.

page_text: Having thus 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 would observe that what I consider novel and
original, and, therefore claim as the Invention secured to me by the
hercin-before in part recited Letters Patent is,-
First. The construction and arrangement of the parts of feathering
propellers or paddles for propelling ships or vessels, all substantially in
the new or improved manner herein described and shown in the accom-
panying Drawings.
Second. The. fulcrumming of the floats of propellers to and between
their side wheels or frames free to turn and feather in both directions to
find their path of least resistance when not propelling, and by a crank
and eccentric guides to assume and maintain, while propelling, an angle
at right angles to the line of propulsion, all substantially as described in
reference to Figures 1 to 13.
Third. The fulcrumming of the floats of propellers free to turn and
feather in both directions on the cranks of a duplex cranks pindle
between the side wheels or frames when not propelling, and by a crank
and eccentric revolving disc or equivalent connecting rods to assume
and maintain, while propelling, an angle at right angles to the line of
propulsion, all substantially as described in reference to Figures 14, 15,
and 16
•
and 16
In witness whereof, I, the said Robert Smyth, have hereunto.set
my hand and seal, this Fourteenth day of June, in the year of
our Lord One thousand eight hundred and seventy-three.