AN IMPROVEMENT OR IMPROVEMENTS ON THE STEAM ENGINE, AND IN THE APPLICATION OF STEAM POWER TO NAVIGATION AND TO LOCOMOTION
Year: 1832

page_text: TREVITHICK, of Cambourne, in the County of Cornwall, Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-second day of September. in the third year of His
reign, did, for Himself. His heirs and successors, give and grant unto me, the
said Richard Trevithick, His especial licence, that I. the said Richard Trevi-
thick, my exors, admors, and assigns, or such others as 1. the said Richard
Trevithick, my exors, admors, 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
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN
IMPROVEMENT OR IMPROVEMENTS ON THE STEAM ENGINE, AND IN THE APPLICATION OF
STEAM POWER TO NAVIGATION AND TO LOCOMOTION;" in which said Letters Patent
is contained a proviso obliging me, the said Richard Trevithick, by an instrument.
in writing under my hand and seal, particularly to describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed,
and to cause the same to be enrolled in His said, Majesty's High Court of Chan-
cery within six calendar months. next and immediately after the date of the
said 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
Richard Trevithick, do hereby declare the nature of my said Invention, as
regards the improvement or improvements on the steam engine, to consist in

page_text: interposing between the boiler and the working cylinder, in a situation to be
strongly heated, a long pipe formed of a compact series of curved or bent pipes,
which I denominate the dry pipes, or steam expanding apparatus, through
which dry pipes I cause the steam, after it has been generated in the boiler
in contact and consequently saturated with water, to pass with very great
velocity, in order that it may imbibe a copious supply of additional beat
without any addition of water, and by this additional heat to be expanded into
a greater bulk of steam, of about the same expansive force that it had acquired
in the boiler, by which means I obtain a greater volume of steam. for use in
the working cylinder than the boiler alone would supply and in order still
further to augment this volume of steam, I place the working cylinder within
a case constituting a part of the flue or chimney, that the cylinder may be kept
considerably hotter than the steam employed in it by absorbing a great portion
of the heat remaining in the flue after having heated the boiler and the dry
pipes, which heat would otherwise pass away out of the top of the chimney
and be wasted, but by this arrangement is converted into a useful power by
further expanding the steam in the cylinder.
And I do further declare, that in carrying this part of my said improvement.
into effect, I do not find it necessary to confine myself to any particular form of
boiler, or arrangement of pipes, in which the steam is to be heated: but by pre-
ference, as being very compact in form, and economical of fuel in using. I
make my boiler of a number of upright pipes, standing upon and communi-
cating with a tubular ring placed around and a little below the fire grate; these
pipes all surround the fire place, except two or three, the lower ends of which
are elevated above the fire door. but connected at the bottom by a branch pipe
united to one of the adjoining upright pipes. thereby leaving an opening or
place of access to the fire. These pipes all extend upwards to the height of
several feet, according to the quantity of steam required to be raised, combined
with local convenience, for it is obvious that the power of this boiler to raise steam
may be increased either by increase of the length of the pipes, of their diameters,
or of their numbers. And I do lay upon the upper ends of the pipes herein-before
described. and connect with them a tubular ring similar to that upon which the
pipes stand, the two rings and the upright pipes forming together a vessel in
which water has free communication by means of the bottom ring to stand
at the same level in all the pipes, and the steam has free communication to
pass from all the pipes into the upper ring and I do. for the sake of obtaining
great heat, place my system of dry pipes over the fire, and within the circular
row of upright pipes of the boiler herein-before described: and I form my dry
pipes in pairs, each pair constituting the figure that is well understood by the

page_text: -
term inverted syphon; and 1 unite several of these syphons together by short
bent pipes at the top, so as to constitute one long zigzag pipe, through which
the steam must successively pass down and up the alternate legs of each
syphon with great velocity, necessary for the rapid absorption of heat in its
passage from the boiler to the working cylinder of the engine, the working
cock, valves, or slide of which being united by a pipe of communication with
that leg which is last in the succession of syphons; and I unite the first in
succession of these inverted syphons with the upper tubular ring of the boiler
by means of a bent pipe, in which a throttle valve or cock is placed in order to
limit the supply of steam, that it may have space in the dry pipes and working
cylinder to expand in proportion as it receives additional heat; and I fix a
safety valve in communication with the boiler, and another in communication
with the dry pipes; and I place around outside the boiler, at a small distance
from the upright pipes, two cylindrical casings, one within the other, and fill up
the space between the two casings with sand, ashes, or other material which
conducts heat but slowly; and I close up the upper end of the casings over
the boiler and the dry pipes with a covering in the form of a dome, and out of this
enclosure I make the flue to pass to and around the working cylinder of the
engine, whence the flue carries the smoke and little remaining heat away in
any convenient manner; and I make my boiler pipes, rings, and casings by
preference of iron or copper, and my dry pipes of copper. or other strong metal
not liable to rapid oxidation by heat when in contact with steam; and I supply
my boiler with water by means of a forcing pump, so adjusted as to keep the
water of the proper height.
And I do hereby further declare, that the nature of my said Invention, as
regards the improvements in the application of steam power to navigation,
consists in the drawing of water into a receptacle placed near within the stern
of the navigable vessel, which water is drawn in through an orifice in the stern
with a moderate degree of velocity in the direction of the course of the vessel,
and ejected with great force and speed in a direction opposite to the course
of the vessel through the same orifice, reduced to about a quarter of the area
by means of a valve opening as the water enters, and partially shutting as the
water is ejected, and thus I propel the vessel with great force, derived from
the recoil of the water set into rapid motion in a direction opposite to the
course of the vessel, the rapidity of the jet of water to be at least equal to
double the required speed of the vessel to be navigated.
And I further declare, that by preference, I effect the purpose of receiving
and of ejecting the water, and of deriving a motive force from its recoil, by
means of a large vertical cylinder of cast iron or other metal closed at both

page_text: ends, in which a piston is forced up and down by a piston rod sliding through
a stuffing box in the lid, which piston rod receives its motive force from a
steam engine; and I fix a tube into the after side of this cylinder. near the
bottom, in communication with the space below the piston, which tube leads
through the stern of the vessel. as low down as practicable, and opens on one
side of the rudder; and I fix another tube into the after side of this cylinder,
near the top. in communication with the space above the piston, which tube
also leads through the stern of the vessel, as low down as practicable, but opens
out on the other side of the rudder; and I place in the mouth of each of these
tubes a valve opening inwards, to allow the water free entrance, equal to the
bore of the tube, and partially shutting when the water is ejected. so as to
reduce the opening through the stern to about one fourth of the area of the
tube.
And I do hereby further declare, that the nature of my said Invention, as
regards the improvement in the application of steam power to locomotion, consists
in the application of such a boiler, together with the expanding apparatus as
aforesaid, to locomotive engines, whereby a diminished weight of boiler and
quantity of water and fuel is obtained; and in further compliance with the said
proviso, I, the said Richard Trevithick, do hereby describe the manner in which
my said Invention is to be performed, by the following description of its various
parts in detail, reference being had to the Drawing annexed, and to the figures
and letters marked thereon, that it is to say:-
DESCRIPTION OF THE DRAWING.
Figure represents a series of vertical sections through the various essen-
tial parts of the boiler, the dry pipes, the steam pipe, the working cylinder, the
propelling cylinder, and the flue, together with sections and views of other
minor parts, serving to shew the connections of the essential ones. The places
at which these sections are taken are shewn in Figure 2 by the dotted line
from A to B, from B to C, from C to D, and from E to F; Figure 2. repre-
sents a plan of Figure 1, with the top coverings of the boiler and working
cylinder removed; Figure 3 shews the manner of uniting the shorter upright
pipes over the fire doorway with one of the adjoining ones, so as to give free
circulation of the water in all the pipes: Figure 4 represents three pairs of
syphons, which in their places stand in a circular form, but in this Figure are
shewn as spread out into a plane, in order the better to explain their structure
and joinings; similar small letters and numbers of reference are used to denote
similar parts in all the Figures; (a) the upright boiler pipes, the upright and

page_text: lower ends of which are contracted to leave 100m for bolt heads and nuts,
without throwing the pipes too far asunder; (b) the tubular ring having a
flanch projecting, inwards and outwards at the upper side, perforated with
apertures upon which the upright pipes are bolted, and another flanch at the
bottom, projecting inwards, to bolt the ring down to the foundation plate; (c) the
foundation plate: (d) the fire grate: (e) the fire doorway () the upper
tubular ring, having a flanch at the bottom projecting inwards and outwards,
and perforated with apertures corresponding with the tops of the upright pipes
upon which the tubular ring lies, and to all which it is bolted; (g) the level
of the water in the boiler pipes; (h) the dry pipes formed like inverted
syphons, so as to require no joining at the lower part near the fire; one leg of
each of the two syphons shewn in Figure 1 is in section, and broken near the
bottom: an outside view of the other leg appears partly behind the section;
(1) the short bent pipes, each bolted to two syphons, to unite them into one con-
tinuous pipe; (!) the bent pipe uniting the upper tubular ing with the first in
succession of the syphons; the proper situation for this pipe is that shewn
in Figure 2, but for the sake of clearness and simplicity in the Drawing, it is
shewn in Figure as if on the left hand pipe and syphon: (m) the throttle
cock on the bent pipe (1): (n), the safety valve lever, and weight on the same;
(p) the pipe of communication from the last in the succession of syphons to the
working cylinder of the engine; (r) the throttle cock in the pipe (p); (s) a
four-way cock, worked by the hand gear, to direct the steam alternately under
and over the piston; (f). the safety valve in communication with the dry
pipes: (a) the two cylindrical casings surrounding the boiler pipes, the
space between the two being filled up with a slow conducting medium; (v) the
domical covering over the cylindrical enclosure; (c) the flue leading out of
the enclosure into the casing of the working cylinder; (c) the casing of the
working cylinder forming a continuation of the flue: (y) the further con-
tinuation of the flue to the chimney; (2) the waste steam pipe leading into the
chimney; (1) the steam pipes leading from the working cock into the top and
bottom of the working cylinder; (2) the working cylinder; (3) the piston
with metallic packing; (4) the piston rod passing down through a stuffing
box at the bottom of the working cylinder, and also continuing downwards, to
form the rod of the propelling piston; (5) the propelling cylinder; (6) the
water or propelling piston; (7) the upper aperture leading to one of the tubes
opening through the stern of the navigable vessel; (8) the lower aperture
leading to the other tube, opening also through the stern of the navigable
vessel; these apertures are made as wide as the cylinder will allow, in order

page_text: that they may have but little depth, and not occasion an inconvenient length
of the propelling cylinder; (9) a frame supporting the steam cylinder upon the
propelling cylinder (10) the feed pump for supplying the boiler with water:
(11) an arm fastened on the piston rod to work the feed pump and hand gear;
(12) the stand gear.
Now, whereas I claim as my Invention, firstly, the interposing between the
boiler and the working cylinder of the steam engine a long many-curved heated
pipe, through which the steam is forced to pass with great rapidity without
being permitted to come in direct contact with water, by which arrangement
the steam is made to absorb additional heat, and at the same time allowed to
expand itself into a greater volume.
Secondly, placing the working cylinder of the engine within such part of.
the flue or chimney as shall insure the cylinder to be kept hotter than the
steam used in it, by which means the expanding of the steam is still further
promoted.
Thirdly, propelling a navigable vessel by the force of the recoil produced
from water receiver with a moderate degree of velocity, into a receptacle near
within the stern, in the direction of the course of the vessel, and ejected. with
great velocity in a direction opposite to that course, the velocity of the jet being
at least double the required speed of the vessel to be propelled, provided always
that the same be effected in manner herein before-described.
Fourthly, applying a boiler combined with a steam expanding apparatus, as
before described, instead of a boiler alone, to a locomotive engine, whereby the
power of the steam is applied after the steam has undergone the expanding
process, and whereby a diminution is effected in the weight of the boiler, and
in the weight and consumption of water and of fuel.
PC
And such my Invention being, to the best of, my knowledge and belief,
entirely new, and never before used within that part of His said Majesty's
United Kingdom of Great Britain and Ireland called England, His said
Dominion of Wales, or Town of Berwick-upon-Tweed, 1 do hereby declare this
to be my Specification of the same, and that I do verily believe this my Speci-
fication doth comply in all respects, fully, and without réserve or disguise, with
the proviso in the said herein-before in part recited Letters Patent contained.
Wherefore I do hereby claim to maintain exclusive right and privilege to
my said Invention.
In witness whereof, I have hereunto set my hand and seal, the Nineteenth
day of March, in the year of our Lord One thousand eight hundred
and thirty-three.
RICHARD
(L.S.) TREVITHICK.

page_text: T
WINGFIELD.
AND BE IT PEVEMBERED, that on the Nineteenth day of March, in
the year of our Lord 1833, the aforesaid Richard Trevithick came before
our said Lord the King in His Chancery, and acknowledged the Specifica-
tion aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.