CERTAIN IMPROVEMENTS IN OBTAINING MOTIVE POWER
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
SALISBURY EAGLES, of Liverpool, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Second day of June, in the third year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Samuel Salisbury Eagles, Her especial licence, full power, sole privilege and
authority, that I, the said Samuel Salisbury Eagles, my executors, adminis-
trators, and assigns, and such others as I, the said Samuel Salisbury Eagles,
my executors, administrators, or assigns, should at any time agree with, and
no others, from time to time and at all times during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
England, Wales, the Town of Berwick-upon-Tweed, and in all Her Majesty's
Colonies and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS IN
OBTAINING MOTIVE POWER;" in which said Letters Patent is contained a proviso,
obliging me, the said Samuel Salisbury Eagles, by an instrument in writing
hand and seal, particularly to describe and ascertain the nature of
under my

page_text: my said Invention, and in what manner the same is to be performed, and
to cause the same to be inrolled in Her Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said in
part recited Letters Patent, as in and by the same, reference being thereunto
had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Samuel Salisbury Eagles, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are par-
ticularly described and ascertained in and by the following description thereof,
reference being had to the Drawings hereunto annexed, and to the letters
and figures marked thereon (that is to say):-
These improvements in obtaining motive power consist in a certain con-
struction and arrangement of machinery applicable to propeiling vessels afloat
on seas, rivers, and canals; a part of which machinery is also applicable to
propelling carriages on railways, on common roads, and also for driving
machinery in general. The particular features of the Invention may be
considered as divisible into two distinct heads; first, a mode of propelling
vessels on water by means of reciprocating pistons, acting in open horizontal
cylinders placed in the stern of the vessel below the surface of the water, such
pistons being actuated by atmospheric steam engines working horizontally, the
pistons at every stroke forcing back the volume of water out of its cylinder,
in order that by the resistance of the water the vessel shall be propelled in the
opposite direction; and, secondly, a mode of communicating the impelling
power exerted by the reciprocating action of a pair of atmospheric steam
engines to a rotatory shaft without the intervention of cranks.
In the accompanying Drawing, Fig. 1 represents the improved machinery
in horizontal section, supposed to be constructed in a ship or other navigable
vessel. a, b, are steam cylinders, open at one end to the atmosphere; c, d, are
pistons, properly packed, so as to fit steam-tight within the cylinders, from
which piston rods e, f, extend, and at their reverse ends are connected to
other pistons g, h, working water-tight in cylinders i, k, which last-mentioned
cylinders are open at both ends; their inner ends to the atmosphere, their
outer ends to the water. This horizontal section is taken below the level of
the water in which the vessel is supposed to be floating. On the inner edges
of the piston rods e, f, racks are formed, which take into a toothed horizontal
wheel e, for the purpose of assisting the reciprocating action of the pistons;
that is, when one of the pistons rods is moving forward, the racks and toothed
wheels may facilitate the retrograde movement of the other piston rod, and

page_text: vice versa. Steam by any of the ordinary means is to be let into the cylinder a
behind the piston c, the expansive force of which will project the piston e
towards the open end of the cylinder; when that has taken place the induction
valve of the cylinder will be shut by the ordinary means, and the eduction
valve opened, by which the steam is drawn off, leaving the interior of the
cylinder a, behind the piston, in a state of partial vacuum. The pressure of
the atmosphere through the open end of the cylinder then acting against the
face of the piston, will force it back again towards the closed end end of
the cylinder, and, on a fresh supply of steam being inducted behind the piston,
the piston will be projected forward, as before. This is the ordinary operation
of an atmospheric steam engine; and when two cylinders are employed in
conjunction, as in the present instance, the opening of the induction valve in
one will cause the eduction of the other to be closed; and hence, the pistons c
and d in the two cylinders a and b will be made to move to and fro recipro-
cally. The mouths or outer ends of the other cylinders i and k being open,
the water will flow freely into them, and occupy the interiors of those cylinders
up to the faces of the pistons g and h; but when, by the reciprocating action
of the piston c and d, produced as above described, the rods e or f are moved
forward, the piston g or h will be projected outward, and displace the volume
of water from the cylinder. In this way, by the resistance of the water against
the face of each piston, a force will be obtained which will impel the vessel in
an opposite direction. It is further to be observed that the horizontal wheel
is mounted loosely upon a vertical axle, and enabled to turn freely, so that as
the piston rod e moves in one direction, its teeth, taking into the wheel Z, will
cause that wheel to revolve, and to drive the rod f in the opposite direction,
so that the advance of the steam piston c, its rod e, and the propelling piston
9, will aid the retrogade movement of the steam piston d, and its rod f,
and propelling piston h. By this arrangement of machinery placed in the
"run" of the vessel, the propelling stroke will urge the vessel forward with
great velocity, and it will be found that the motive power is doubled by the
saving of thirty-three and a half per cent., usually lost by the paddle wheels,
and twenty per cent. by the ordinary use of the cranks; and further, the
reaction of the steam being always toward the head of the vessel, will aid the
propelling power; and also, the atmosphere acting upon the steam pistons
against a vacuum formed in the steam cylinder behind it, will throw a force of
seven pounds in every square inch of the piston's surface upon the horizontal
wheel, and through it upon the other steam piston, aiding its retrograde move-
ment, and thereby contentrating a force of fourteen pounds on every square

page_text: inch upon the centre of the horizontal wheel, which pressure is toward the
head of the vessel; the air also rushing into and out of the cylinder, acts as
a further motive power in propelling the vessel.
In applying a part of this machinery to the propelling of carriages on
railways and on common roads, or for the driving of machinery in general,
I adopt the arrangeinent shewn in the horizontal view, Fig. 1, with the
exception of the pistons 9 and h, and the cylinders i and k, and add thereto
a pair of toothed sectors, working vertically, mounted upon a horizontal
shaft, through which the impelling power is to be communicated for driving
the running wheels of a carriage, or the main driving wheel of any other
kind of machinery. This modification of my Invention will be further
illustrated by the sectional elevation at Fig. 2. One of the two steam
cylinders, as above described, is shewn at b, and its piston at d. The
shafts e and in this modification have racks or teeth formed on their upper
surface as well as upon their inner edges, and the two vertical segment
racks m and o both take into these racks on the faces of the piston rods, and
work loosely upon a horizontal axle or shaft n, which shaft turns freely in
plummer blocks upon standards p, fixed at the sides of the machinery. The
reciprocating action of the steam pistons c and d, and their rods e and f, as
before described, give a reciprocating rotary motion to the horizontal wheel l,
and this reciprocating rotary motion of the wheel 7, through the teeth upon
its face, actuates the two segment racks m and o, causing them to oscillate
as the steam pistons move to and fro. To cach of the segment racks a spring
click is attached, which takes into a ratchet s, affixed to the horizontal
shaft n. Hence it will be perceived that as the segment rack moves in one
direction the click will take hold of the ratchet and drive the shaft round
with it; but as it moves in the opposite direction, the spring click will slide
over the ratchet without acting upon the shaft. As the two segment racks
move simultaneously in opposite directions, one of the clicks is inoperative
upon its ratchet, but the other click is then driving the other ratchet, and with
it the shaft n. It will now be seen that by the reciprocating movements given
to the steam pistons c, d, their rods e, f, and the wheel will be actuated, and
cause the segment racks m and o, and their clicks r, r, to act upon the ratchets,
and give such movements as will produce in the shaft n a continuous rotary
motion, which rotary motion may be communicated to the running wheels of
locomotive carriages, or be applied to the actuating of other machinery. By
this construction of machinery the steam power is kept continually in effective
operation, and is always equal or uniform in force, which is not the case where

page_text: cranks are employed to communicate a rotary power to an axle; and by thus
giving rotary motion to the shaft a saving of power equal to twenty per cent.
over the crank is effected.
In witness whereof, I, the said Samuel Salisbury Eagles, have hereunto
set my band and seal, this First day of December, in the year of
our Lord One thousand eight hundred and forty.
SAMUEL SALISBURY (L.S.) EAGLES.
Signed, scaled, and delivered (being first duly stamped)
by the within-named Samuel Salisbury Eagles, in
Sol, Liverpool.
AND DE IT REMEMBERED, that on the same First day of December, in
the year above mentioned, the aforesaid Samuel Salisbury Eagles came before
our Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute in that case made and provided.
DERED,
the sa
rst day
recer
the year above mentioned, the aforesaid Samuel Salisbury Eagles came before
our Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute in that case made and provided.