IMPROVEMENTS IN THE APPLICATION OF MOTIVE POWER FOR LOCOMOTIVE AND OTHER PURPOSES
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LIONEL HOOD, of Saint John's Wood, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Ier
Royal Letters Patent under the Great Seal of Great Britain, bearing dato at
Westminster, the Third day of June, in the eighth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said John
Lionel Hood, Her especial license, full power, sole privilege and authority,
that I, the said John Lionel Hood, my executors, administrators, and assigns,
and such others as I, the said John Lionel Hood, my executors, adñiors, 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, and the Town of Ber-
wick-upon-Tweed, and in all Her Majesty's Colonies and Plantations abroad,
and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, an Invention
of "IMPROVEMENTS IN THE APPLICATION OF MOTIVE POWER FOR LOCOMOTIVE AND OTHER
PURPOSES," being a communication from abroad; in which said Letters Patent
is contained a proviso, obliging me, the said John Lionel Hood, by an instru-
ment in writing under my hand and seal, particularly to describe and ascertain
the nature of the said Invention, and in what manner the same is to be per-
formed, and to cause the same to be enrolled 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Lionel Hood, do hereby declare that the nature of the said Invention,
and the manner in which the same is to be performed, is particularly 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):-
In this Invention there are three distinct branches, which may be used either
separately or combined. The first, part embraces the compression of water, oil,
or other suitable fluid, on the principle known in England as "Bramah's hydro-
static or hydraulic press; the second part relates to the use of springs of a
spiral, circular, or other suitable form, giving action to machinery by their
relaxation, having been previously wound up or coiled up to their full tension
by a crane or any other suitable means, to be used as a magazine of power, as
occasion requires; and the third part of the Invention refers to an improved
mode of obtaining and applying steam, heated air, and other expansive gases to
be employed as a motive power. The whole being applicable to various
mechanical purposes, as driving or giving action to machinery, &c.; (the two first
of which may be employed either separately or together, forming one combined
engine orce of machinery,) and having one definite object, as the propelling
of vessels at sea, and also for propelling carriages and trains on railways,
pumping water from mines, &c., and for various other purposes for which
steam power is generally employed.
The construction of these improved engines, together with their principle
and mode of application, will be fully understood by the following description,
reference being had to the Drawings or Diagrams hereunto annexed, wherein
the same letters and figures uniformly represent the same parts.
Fig. I. is a vertical section of a hydrodynamic engine, in which A is a
tank containing water (or other suitable fluid) forming the base of the engine,
which (as far as the action of the pumps) is similar in its principle to the
hydrostatic machine, known in England as "Bramah's press," the action
and mode of operation of which is well known and understood by scientific
engineers; B, the large cylinder, with its ram or piston C, working through a
stuffing box packed in the usual manner as practised with Bramah's hydraulic
presses. Attached to the piston C is a toothed rack or cogged bar D, w ing
into the pinion or small wheel E, which carries on its axis the large wheel F,
by means of which it communicates the motion to the small wheel G, which in
its turn may be made to drive other wheels on the same principle, or may
communicate its motion direct to the working shaft. The application of the
toothed bar or rack D, together with the introduction and applications

page_text: the wheels and pinions, and the arrangement and mode of working the pumps,
constitute the Invention and improvements, the engine of Bramah being only
applicable as a press. H are small force pumps, working into the cylinder B
through the medium of two hollow pipes or drums I, transverse sections of
which are shewn in Fig. I., and the plan or horizontal position in Figs. 2 and 3,
where they are seen forming the communication between 18 of the small
pumps and the cylinder B; but I would have it understood that these are
merely shewn as examples of the mode of forming the connexion, the engine
not being limited to any particular number of pumps.
Fig. 3 represents one of the drums I, connected with two large cylinders,
the connecting or inlet pipes being each furnished with a powerful screw valve
M, to enable each cylinder to be worked separately, one being constantly shut
off, the object of which will be presently understood. K is the outlet or
escape pipe, to allow the water in the cylinder B (when the same shall be full,
and the piston or ram raised to its full height,) to return to the tank A, for the
purpose of lowering the ram or piston C; this pipe is closed by a strong screw
valve and lever, as shewn in Fig. I. The axis or shaft of the wheel F and
pinion E is made to slide or shift, so as to put either of the racks D in or out
of "gear" or connection with one or other of the pinions E (see Fig. 3).
L are counterpoised levers (fixed to the frames of the machine) for working
pumps is
and increasing the power of the force pumps H; each of these
furnished with its lever, which may be worked separately, or they may be
connected with a transverse bar, and any suitable and convenient number
worked together, at the option of the constructing engineer. To put this
engine to work, one of the large pistons C being put into gear or connected
with its pinion E, the piston being down, and the valve or screw K closely
shut, the force pumps H are to be put in motion by manual or other suit-
able power, when the piston or ram C will be slowly raised, and by driving
up the toothed rack D, will turn the pinion E, which carries on its axis the
wheel F, giving action to the small wheel or pinion G, which may be employed
to turn the working shaft direct, or to set in motion a train of wheels and
pinions similar to E and F, by which means any practicable amount of speed
may be obtained, the small wheel or pinion being driven by the large wheel
fixed on the axis of the preceding pinion, the velocity being increased in pro-
portion to the difference in the diameters between the wheels and pinions, and
the number of such wheels and pinions employed, the ratio or proportion of
which must therefore be regulated by the speed required; but in general it
will be desirable to make the large wheels of as great a diameter as will con-
veniently work in the space allotted to them, and the small wheels or pinions

page_text: of as small a diameter as is consistent with requisite strength; and if G be made
the working shaft, it will be evident that the greater the diameter of the wheel
G, the greater will be the power gained, and the smaller it is made, the greater
the speed. The engineer in constructing the machinery will therefore regulate
the ratio of these wheels according to the work required to be done. The
drums I enable a considerable number of force pumps to be used simul-
taneously, instead of limiting the action of the machine to one or two, as is
generally done in the hydraulic or hydrostatic machines of the ordinary con-
struction, known in England as "Bramah's presses." Each of the small
pumps H is furnished with two strong valves, as shewn in Fig. 1, the top
valve opening inwards, and the side valve leading to the drum (I) opening
outwards, as in ordinary force pumps (as is well known and understood); the
smaller the diameter of the pistons in the force pumps (H), as compared with
the diameter of the large pistons or ram C, the greater will be the power
gained, and the greater the number of force pumps (H) used, the quicker the
working pistons C will rise, and consequently the greater the speed of the
engine (as derived from the wheel G). Two cylinders (B) are used in order to
obviate the necessity of stopping the engine when the piston or ram C shall
have arrived at its full or maximum height, when the piston of the other cylinder
(B) being previously lowered down, the "couplings" or connections are shifted
by any of the usual mechanical contrivances which are well known to practical
engineers, and the pumps are immediately connected with the other cylinder
(by means of the screw valves, shewn at M, Figs. 1, 2, and 3,) and the operation
goes on as before; after which, the valve K being opened, the water is dis-
charged from the full cylinder, and the ram or piston C is lowered down to be
again used as at first. Now, it is evident that the greater the length of the
large cylinder and piston B and C, the greater will be the range of the cogged
rack D, and consequently the greater the number of revolutions of the large
driving wheel F will be obtained before the piston C will have arrived at its
maximum height, therefore (when the space will allow it) the cylinder and
piston B & C with the cogged rack D should be made of as great a length
as practicable and convenient. The effective power of the engine will of course
depend on the difference of the diameters of the working piston or ram C, as
compared with the pistons of the small force pumps II; thus, if the diameter
of the small pistons be one inch, and the diameter of the piston C be twelve
inches, the effective power is as one hundred and forty-four to one, multiplied by
the difference of the length of the lever L, as compared with the length of its
"fulcrum" (as in the hydrostatic press of Bramah), the power gained being
always as the square of the diameters between the large and small pistons, mul-

page_text: tiplied by the length of the lever working the pump H, so that the strength of
the materials is the only limit to the power this engine is capable of affording.
Fig. 4, 5, 6, 7, and 8 represent an improved mode of imparting motive
power to machinery by means of spiral springs, similar to those employed in
watch and clock work. Fig. 4 is a profile of a spring drum or box and spiral
spring, suitably constructed for carrying out this part of the Invention. M² is
a hollow box or drum, formed of wood, metal, or any suitable materials, con-
taining one or more circular coils of springs, one end of each being attached to
the interior of the drum or case, and the other end connected with the move-
able axis, similar to the main-spring of a watch, the plan of which is shewn at
Fig. 6. Fig. 5 is a side view of the spring box with its chain and wheel.
P is a wheel with spiral grooves, similar to the "verge" in a watch, the use of
which is to equalize the force of the spring as it unwinds itself or becomes
relaxed, precisely similar to the action of a watch spring and chain (but this
part may be dispensed with, at the option of the engineer, where an equality
of tension is not important). The apparatus as thus constructed is suitably
arranged for conveying a vibratory motion to the levers L of the force
pumps, Fig. 1, in lieu of employing manual power, the spring being coiled
up tight by any suitable means applied to the movcable axis, and held
by a ratchet or catch; the chain being previously coiled or wound round
the conical wheel or drum P, the action of the spring (when set free) will
cause the smaller drum P to revolve and turn the wheel Q, by means
of a pinion fixed on its axis Q, in its turn driving the small wheel or
pinion R, to which a crank may be attached, working in a slot or groove in the
long ends of the lever L; a vibratory motion will thus be obtained, and the
crank, by alternately raising and depressing the lever L, will communicate
the proper motion to the force pumps H. The series of wheels and pinions
may of course be prolonged to any required extent, according to the strength
or power of the spring used and the velocity of the required motion.
The mode of working the pumps by means of the springs is more fully
explained at Fig. 7, where the spring drum (M²) carries on its axis a spur
wheel, driving a short train of wheels which are connected to the levers L by
a double crank, each revolution of which performs two strokes; or by furnishing
the last wheel with double cranks on each side, four pumps may be worked at
the same time (or more if required) by increasing the number of the cranks,
according to the power of the springs employed. This will be fully understood
by reference to Fig. 7. The axis or "arbor" of the spring drum should
be provided with a ratchet or check catch, to prevent the spring relaxing or
uncoiling itself until it is relieved, by removing the check or catch, as before

page_text: described at Fig. 7, by which means any required number of springs may be
kept ready wound up for use, and may be connected by any of the known
couplings or modes of connections, using a fresh spring to keep up the motion
as the last one becomes relaxed. Thus, any requisite and convenient number
of springs with their drums may be carried on a railway, and used as a maga-
zine of power to propel the train (a practicable and convenient mode for which
will be more fully described hereafter). The relaxed springs may then be
conveniently wound up or re-set at the terminus, or at any of the stations,
by means of a suitable crane, or other stationary power, and kept ready for,
future use. The motion may be quickened for various purposes by providing
the periphery or circumference of the spring drum M² with cogs or teeth,
taking the motion therefrom, making the large wheel work into a smaller
one, as shewn in Fig. 8, when the number of revolutions of the small
wheel will be in proportion to the difference of its diameter as compared with
that of the large one, which proportion and the number of wheels and pinions
must be regulated by the engineer who constructs the machinery, according to
the rate of speed required.
Now, I do not limit this Invention or confine my claim to any particular
size of the engines or to the dimensions of its separate parts, which may be
considerably varied without destroying the intended effect; and as the uses to
which the said engines may be applied are very various, the size and relative
proportions will be readily regulated and adjusted by a practical engineer
acquainted with the principle and action of Bramah's press, from which this
improved hydrodynamic engine is derived. As a good medium size (for a
powerful engine), I would recommend the working cylinder B to be made
about eighteen inches internal diameter and about six feet six inches in height;
the piston or ram C being about sixteen inches diameter, with a working
stroke of six feet six inches; but where great power is required (as in pro-
pelling a ship at sea) the piston may be made twenty-four or thirty inches
diameter (or more), and the working stroke as long as the space appropriated
for the engine will allow; or two or more smaller cylinders may be used
simultaneously, each piston carrying a separate rack or cogged bar. The
cylinders B may also be fixed at any desirable angle or position, according to
the wish of the superintending engineer when constructing and fixing the
same (giving them sufficient inclination to allow the piston to be lowered
when requisite). The sides of the working cylinders B must be very strong
to resist the pressure to which they are to be exposed, say about three and a
half inches thick (according to sizes), greater strength being requisite in the
cylinders of this engine than in those of a steam engine, as the pressure in this

page_text: instance is equal and continuous in all directions. The small pumps H may
be about eighteen inches in length, and the pistons about half an inch in
diameter; these pistons should be made of solid metal of the same thickness
throughout (which is preferable to all kinds of packing), all the pistons in this
engine acting as "solid plungers;" but to avoid unnecessary weight, the rams
or great pistons C may be made internally hollow, provided sufficient thickness
be employed to resist the pressure to be sustained, and that they are properly
closed by a strong plate at the bottom. The large wheel F may be about
twelve feet in diameter (this will be regulated by the length of the rack D
and working stroke); the wheel G about twelve inches diameter; the
lever L about fifteen inches in the fulcrum and ten or twelve feet in length
(more or less, according to working space and convenience). The drums I
may be made proportionally strong with the working cylinders (B), as they
will be exposed to a similar pressure; they are secured at each end by strong
metallic plates, "bolted" or screwed to its "flanges." The diameter of these
drums may be five or six inches internally and ten or twelve feet in length (in
proportion to the number of pumps intended to be used). I would remark
that the comparative diameters of these drums are purposely exagerated or
increased in the diagrams and sections, in order to explain their construction
more fully with the position of the internal valves. The tank.A may be five
to six feet square by three feet in depth (or less, according to the size of the
engine). The axis of all the wheels must be made very strong to sustain
the great power to which they will be subjected, as will be readily understood
by practical workmen accustomed to the construction of steam and other
engines. The spring drums M², Figs. 4, 5, 6, 7, 8, and 14, may be ten or
twelve feet in diameter and about eighteen to twenty-four inches in breadth
(according to the power required); the springs being each formed or made in
segments or parts, and composed of tempered steel bars, of from a quarter to a
half inch or more in thickness, and about two inches in breadth, each segment
being properly fastened together by screws, &c., so as to form one entire
length, and coiled up, so as to allow about six or eight inches space between
the coils to allow freedom of action; six, eight, or more of such 'springs may
be placed side by side in the same drum or box (M²), and connected with the
same axis, which will constitute a combined spring of considerable power,
which may be wound up by a powerful crane (or by a small stationary engine
when the springs are employed for locomotive purposes). Strong spring
catches or "cliquets" must be attached to the drum, to enable the engineer to
stop its action whenever it may be desirable, and also to enable him to wind
the spare springs and maintain them at their full tension until. required for
up

page_text: 66
use, when they may be connected with the working axis or shaft, or to a train
of wheels placed between, (as will be hereafter described and explained,) by
coupling boxes," or by any of the known methods employed for connecting
and disconnecting machinery. Now, the hydrostratic engine, Fig. 1, may be
employed in lieu of a steam engine for working floating vessels of all kinds,
and for all such machines as require great power, heavy railway trains, &c.,
either with or without the assistance of the spring power, before described, the
speed of which may be rendered considerable by multiplying the number of
pumps and increasing the diameter of the driving wheel F, or by using a
greater number of wheels and pinions, the large wheel working alternately
into the following small one, as shewn in Figs. 9, 11, 12, &c. (as will be
presently described), or by any of the known mechanical contrivances with
which practical engineers are well acquainted.
It is obvious that a combination of levers may bo used instead of the wheels
here described acting on the same principle; I therefore do not limit my
claim to the precise arrangement here shewn, so long as the principle is
suitably employed and arranged for carrying out the intended effect; but I
prefer and recommend the arrangement herein described and explained as best
calculated to carry out the object of the Invention. The use of the hydraulic
drum or chamber I is not indispensable to this Invention, as the force pumps H
may be connected to the cylinder B direct, as shewn in Fig. 10, which arrange-
ment may be suitably employed in engines of the smaller size; I do not,
therefore, confine my claim to the use of such hydraulic drums or chambers,
but I recommend them as a means for better carrying out the object of the
Invention, by enabling a greater number of force pumps to be used with
facility.
Having now described the principle and general features of the two first parts
of this Invention, and given general instructions as to the manufacture of the
engine, I now proceed to shew some further modifications of the same, and also
the further application of motive power obtained by means of springs. These
modifications consist in certain means for reversing the action of the machinery
at pleasure, in order to render the Invention available under all the exigencies
that may ensue in its application for locomotive purposes, either on railways or
at sea, &c. Fig. 11 represents an elevation, and Fig. 12 a horizontal plan
or section, of the moving parts of an engine or machine constructed according
to the mode above referred to. C, Fig. 11, is the ram or large piston, with
its toothed rack D, which is now seen furnished with teeth or "cogs" on each
side, with facilities for connecting either of the pinions E or S at pleasure, the
mode of doing which is seen in detail in Fig. 12 (as will be more fully

page_text: described hereafter). E and G are the two small wheels or pinions; and F,
the large driving wheel, as originally described; S, T, V, and W being the
additional wheels required to reverse the action of the machine, and turn
the working shaft G in a contrary direction. D, Fig. 12, are the toothed
racks, attached to and driven upward by the ram or great piston C; two of
such racks are shewn in the plan to exhibit the mode of alternating or chang-
ing the connexion with either of the large cylinders B, for the reasons before
explained, and described at Fig. 3, to afford the working engineer the means of
lowering either of the pistons C, when at its maximum height or the extent of
its range. The lower rack in Fig. 12 (which with its connecting machinery is
for distinction marked No. 1) is seen in "gear" or connection with the pinion
E, communicating the motion direct to the pinion G, by means of the driving
wheel F. The other rack D, seen in the upper part of the Figure (which with
its connecting machinery is marked No. 2,) is at rest or down, being discon-
nected or out of gear with either of the pinious, and ready for action when
required, when it is put in connection with its pinion E, by means of the
sliding axis, to which the wheel F and pinion E are fixed. The parts colored
black represent the upright bearings or pillars, supporting the axes of the dif-
ferent wheels and moving parts. Now, supposing the cylinder and rack, marked
No. 1, be at work, and it be suddenly required to reverse the action of the
engine (as frequently occurs on railways); the wheels E and F are thrown out
of gear or connection with the rack D by traversing or sliding the axis to
which they are affixed by means of a suitable lever (or by any of the modes
known to practical engineers), by which action the rack D and shaft G are
simultaneously put out of connection, and, by a similar operation, the moveable
axis carrying the wheels S and T being traversed or moved onward in its
bearings, the reverse side of the toothed rack "takes into or connects itself
with the pinion or small wheel S, and the large wheel T, into the small wheel V,
which in its turn works into and drives the small wheels W and X, thus at
onco turning the working axis G in the contrary direction to that in which it
was previously working. The original or direct motion (when required) is then
again obtained by reversing the connections, and placing the pinion E in gear
(or connection) with the rack, as before. Now, to maintain and continue the
action of the engine when the piston and rack No. 1 is at its full height or
furthest extension, the rack D and pinion G are set at liberty by moving the
sliding axis E and F, as before described, and the rack No. 2 put in "gear"
(or connexion) with the pinion E by the same means. The action of the
working shaft then goes on direct, as before, and if a retrograde or backward
motion is required, it is immediately obtained by disconnecting the pinion E
"

page_text: and connecting S, when the action of the shaft G will be reversed, as before
described with respect to No. 1, the moving parts of each cylinder being pre-
cisely similar. Fig. 13 is a vertical section of one of the large cylinders B,
with its ram or piston C, in which the escape pipe and screw valve K, formerly
shown at the bottom of the cylinder, is now shewn at the top, which arrange-
ment is superior to the former when the cylinders are placed vertically, as the
water can be discharged and the piston lowered without emptying the body. of
the cylinder so completely by which means, the space between the cylinder
and piston being always kept full, the force pumps II will begin to act in raising
the piston immediately they are set to work, instead of expending part of their
power in refilling the said space before the bottom of the piston or ram C
will be acted upon by the pressure. Fig. 14 represents a plan or horizontal
section of the moving parts of a machine or engine mounted with three spring
drums, as described at Fig. 8, with suitable machinery for reversing the motion
and producing a retrograde action at pleasure. M² are spring drums, furnished
with cogs or teeth, constituting the wheel No. I., working into the small wheel
or pinion 3, which carries on the same axis the large driving wheel 10, turning
the working shaft 5 by means of the wheel 4. These small wheels 4 and 5
are made of double the width, as compared with the other wheels, for reasons
which follow:-The wheel and pinion 3 and 10 are affixed on the same axis,
which is made to slide or "traverse" in its bearings, as shewn in the Drawing,
to produce a retrograde motion, the pinion 3 being thrown out of gear or
(disconnected) with the drum or toothed wheel 1, by traversing the sliding axis,
which at the same time causes the large wheel 10 to take into or connect itself
with the small wheel 9. The pinion 6 is put in connection with the wheel 1,
and the wheel 7 with the pinion 8 simultaneously (by means of the sliding axis),
when, the motion being derived from the reverse side of the drum, the action
of the working shaft will be reversed (the wheel 10 never having quitted the
wheel 4, notwithstanding its axis having been shifted, in order to connect it
with the wheel 9), in consequence of the double width of the small wheel 4,
which allows the large wheel to be traversed or shifted without itself being
thrown out of gear (or disconnected). Three spring boxes or drums with their
separate train of wheels are here shewn mounted together, in order to exhibit
the mode of sustaining and continuing the action of the engine when the one
last used shall have become powerless by the complete relaxation of its springs;
when this is the case, the wheels 10 and 3 are thrown completely out of gear
or connection with the wheel 4 by traversing or moving its axis double the
distance formerly directed, so as to throw the wheel 10 past the wheels 4 and
9 on the left of the Drawings (as shewn in the two drums to the right hand in

page_text: Fig. 14), when the wheel 1 being liberated the drum becomes free, the motion
of the engine being meantime continued by the second or third drum M³, by
connecting the wheel and pinion 1 and 3, as before described. Fig. 14 is
essentially the same as the engine last described, with the addition of the large
wheel 11, between the pinions 4 and 5, the object in this case being to increase
the number of revolutions of the working shaft 5 before the action of the
springs cease, in order to travel a greater distance on a railway or other road
before it becomes necessary to "traverse" the shifting axles, to change the con-
nections from the spring drum, which has become relaxed and expended its
power, to one wound one up and ready for renewed action, as before explained.
In this engine the pinion 3 is thrown out of gear, as described in the last Figure,
for the above purpose; but the wheel 10 never quits the small wheel or pinion 4,
which is made of the same relative width as in the engine last described, and
carries on its axle the large wheel 11, which is permanently connected with
the pinion 5, which turns the working shaft. One of the drums is shewn in
gear or connected with the pinion 3, the action of the engine being direct; the
other two drums are shewn out of gear, and entirely free from either of the
pinions, and are supposed to be wound up and ready for use when required,
being held or retained by their "cliquets" or check catches, and ready to pro-
duce either direct or retrograde motion as the pinions 3 or 6 are thrown into
gear, by traversing either of their respective axles, as before described. In the
position here shewn, both the small wheels or pinions 8 and 9 are shewn con-
nected with the wheels 10 of the two still drums, but turn on their axles free
and ready for producing retrograde action by one motion or shifting of the axle
carrying the pinion 6, and wheel 7, while in direct action they cease to revolve,
as, by throwing into gear 1 and 3, 9 and 10 become disconnected.
Note. The drums M³ in this arrangement are never shifted, their axles not
being made to slide on account of their weight, the axles of the wheels being
used in preference, while the springs in this arrangement are always wound up by
acting on wheel 1 at its circumference. It will be evident to a practical engi-
neer that the combination last described secures the advantage of being enabled
to travel a considerable distance by the power or tension of each spring drum,
and obviates the necessity of so frequently shifting the connections, owing to
the relaxation of the springs. The same principle applies also to all the
engines previously described, and may be carried out by the addition of one or
more axles (each carrying its wheel and pinion) between the last one, shewn in
the Drawing, and the working shaft. A good practical proportion between the
wheel and pinion will be twelve to one, as compared with the relative number
of cogs or teeth with which cach is furnished, which will afford a ready means.

page_text: of calculating its power and speed. Fig. 15 represents a side view and eleva-
tion of a machine constructed with a spiral spring, and driving a toothed rack
acting on wheels and pinions, similar to the previous arrangements; speed
being acquired by causing each pinion to carry round on the same axis a
wheel of large diameter, acting in its turn on another pinion, carrying also
its wheel, the series being prolonged or shortened, according to the purposes
to which the power is to be applied. 11 are two strong guide posts, between
which the spring or springs is placed; 12 is a solid piece of timber or strong
metal plate, to which a toothed rack is attached. This piece constitutes the head
of the spring, and may be called the "driver," and slides between the guide posts
as the spring extends itself or becomes relaxed, driving forward the rack 13,
which, acting in pinion 14, turns the large wheel 15, which is fixed on the same
axis. This in its turn acts in the second pinion 16, driving wheel 17, which may
be made to act on the wheel 18, moving the working shaft, the diameter of
the several wheels being varied and regulated according to the purpose for
which the engine is designed,and the speed with which it is required to work.
The range of the spring and length of the toothed rack 13 may vary from six
to nine fect in length (or more if required), and the wheels and pinions may
be of the same dimensions as before described at Figs. 8 and 9. The
spring may be formed of several short lengths, which need not in this case be
fastened together, as directed with respect to the segments in Fig. 6, as when
placed together they will press one against the other, and thus act in com-
bination as one; they should, however, be made very strong, similar to the
springs or "buffers" employed to break the force of concussions on railway
engines, and used at the railway stations for that purpose. These springs
may be made of considerable amount of power, which may be further increased
by placing several of such springs together side by side, each possessing the
same range and power, and acting on one and the same driver or plate (12)
and rack (13). The ends of all the racks herein described must of course be
properly confined by suitable ties or grooves connected with the framework of
the engine, to prevent their quitting or becoming released from the pinions or
small wheels in which they are intended to act. Fig. 16 represents a side
view of another machine, constructed with a powerful spring or springs,
somewhat in the form of a carriage or coach spring, and constructed of several
separate plates of different lengths placed one on the other. The action of the
rack and of the wheels and pinions being the same as in the last Figure, no
further description will be necessary. A battery or magazine of great power
may be readily constructed by placing several springs, cach as strong as
practicable, side by side, as described in Fig. 15, making them act on the same

page_text: 46
driver and rack, and determining their energy upon one point of motion.
Either of the last form of springs may be conveniently brought back to their
utmost tension by means of a strong chain, passing through the centre of the
spirals and attached to the driver 12, and drawn up by a capstan or other
suitable means; or a powerful crane may be applied to the teeth or cogs of
the rack, Fig. 16, at the option of the engineer. A double range of wheels
may also be employed for reversing the action of the shaft 18 and 21, furnishing
the rack with teeth or cogs on each side, as in Figs. 11 and 12. A spring
cliquet" or check catch must also be attached to the chain (or to the driver
12), to enable the engineer to stop the action of the springs whenever it may
be requisite. A fly wheel may be fixed on the working shaft to regulate the
momentum in any of these engines, as may also be employed cranks or
excentrics and connecting rods, communicating the motion from one part of
the machinery to the other at the option of the constructing engineers, to
whom such applications will be obvious. The two latter machines or engines,
Figs. 15 and 16, are also applicable to a great variety of uses, both for
stationary and locomotive purposes, for propelling carriages on common roads
or on railways, working small boats on rivers, lakes, and canals, and for general
purposes for which small steam engines are now used.
The third and last part of this Invention consists in an improved engine
and means for gaining and applying power for locomotive and other purposes
by means of heated air, and a mixture of expansive gases with or without the
admixture of steam, which will be fully understood by the Drawings and
Diagrams now to be described, where the Invention is shewu applied to the
purposes of locomotion.
Fig. 17 is an elevation, Fig. 18 a plan, and Fig. 19 a vertical section, of
a locomotive engine, constructed according to the principles of this Invention,
the wheels in the latter Figure being removed, in order to explain the internal
construction and arrangement of the several parts of the engine more fully,
the same numbers uniformly representing the same parts in all the Figures.
22 is an iron chamber or case, containing a furnace and a convolution of
metallic pipes (which I term "the calorifere "), and the working cylinder and
piston; the chamber or case 22 terminating in a funnel or chimney, having on
each of its two sides a "slot" or opening, to allow a transverse beam or con-
necting bar attached to the piston rod of the cylinder 25 to traverse up and
down, in order to convey the motion to the crank of the driving wheel 33; the
space between the furnace and the slot containing the pipes and cylinder
thus constitutes a hot air chamber. 27 is a series of air chambers, which I
term the "refrigerator," formed of separate close partitions, as seen in the

page_text: plan, Fig. 18, where each partition or chamber, of about eight feet long by six
feet deep, and about one and a quarter inch internal breadth, is made to com-
municate alternately with the next by means of pipes, leaving free air spaces
of about two inches between each, and also through the entire length of the
chamber or refrigerator; or, insted of the above, a convolution of refrigerating
pipes may be employed for the same purpose. This apparatus is connected
with the hot air chamber in front by the open pipe 26, and with an air
pump at the back by means of the pipe 30, each connection being made
with the opposite partitions in order to cause the internal draught to circu-
late through the entire surface of the refrigerator. The inlent pipe 30
terminates in a double branch, communicating with each end of the air
pump or cylinder, which is furnished with a slide or valve in the usual
manner of steam engines. The outlet pipes are placed opposite to the
inlets at each end of the cylinder, being also furnished with valves opening
outward and communicating with the pipe 31. The pump or cylinder 28
thus possesses a double action, each stroke of the piston both exhausting and
condensing, as will be more fully described. The pipe 81 communicates
with a horizontal convolution of pipes (the cross section of which is seen at
Fig. 19, and plan at Fig. 20,) placed above the furnace, which are thus kept
at a very high temperature, and which I term the "calorifere," their use
being to expand the condensed air and gases thrown into them by the pump
or cylinder 28, prior to the entrance of such gases and vapours into the heated
cylinder 25; these pipes may be placed vertically or in any suitable position,
but I prefer the horizontal arrangement herein described. Now, to set this
engine in motion (the furnace and pipes being properly heated,) the pump 28
must be first set in motion by manual or other suitable power, when the heated
air, gases, and vapours will be drawn from the chimney or hot air chamber
through the open pipe 26, and entering one of the outer partitions or flat
chambers of the refrigerator 27, traverse its entire surface, the air and vapours
parting with their caloric in their passage, and becoming thereby cooled down
to the lowest practical limit; they then make their escape at the opposite side
of the refrigerator, and are drawn into the air pump through the pipe 30, and
by the following stroke of the piston are forced through one of the outlet valves
(through the pipe 31) into the hot tubular chamber or "calorifere" before
described, when the gases and vapours attain a very high temperature, and
expand in bulk or volume in proportion to the heat acquired, according to the
known laws regulating such phenomena, and by their expansive force give
action to the piston in the heated cylinder 25, which is made to communicate
its motion to the cranks of the driving wheel 33 by means of a transverse

page_text: beam moving in the slots or openings in the funnel or chimney before described,
and attached to the cranks by moveable connecting rods, which turn freely at
each of their extremities (or by any other suitable contrivance). The cylinder
25 is constructed in all respects as those used in steam engines, the valves
being opened and shut by any of the well-known mechanical contrivances,
taking their motion either from the transverse beam attached to the piston rod
or from the crank axle, or any of the moveable parts of the engine, at the
option of the constructing engineer; being also furnished with short hand
levers, made to project through a small opening in the chimney or case, in order
to give the engine driver complete controul over them. The pump 28 may be
subsequently worked by the engine itself by means of a friction band attached
to the driving wheel, by means of a concentric wheel placed internally, as
shewn in Figs. 17 and 18, and passing over the smaller wheel (29); placed
at the back of the engine, carrying a crank or excentric, connected by a
moveable bar to the piston rod of the air pump, as seen in the Figures, or the
pump may be worked by the application of springs, described in the second
part of this Invention; or, instead of drawing the heated air and gases
the fire chamber, as before described, the refrigerator and air pump may be
connected with the hot cylinder, and made to produce a vacuum therein by
abstracting the gases and vapours from the ejection pipe; after they have per-
formed their office in the 'cylinder, the said gases and vapours being made to
pass through the refrigerüitor are first cooled down, and the action of the air
pump are again forced' through the calorifere into the hot cylinder and used
de novo.
from
A further improvement consists in the use of an additional cylinder 40, placed
within the funnel or chimney 22, as seen in Fig. 21, the piston of which may be
driven by the heated gases and vapours ejected from 'the cylinder 25 after they
have performed their office in giving action to, and propelling the driving wheel
of, the engine. This additional cylinder may then be worked free of additional
cost, and its piston rod may be made to cominunicate its motion to that of the air
pump 28 by means a vibrating beam, or by cranks and connecting rods, or any
other suitable means known to practical engineers, in lieu of the mode before
described.
Steam may also be advantageously employed as an expansive
agent in addition to the gases and vapours already specified, a convenient mode
of effecting which will be very readily seen and understood by reference to
Fig. 20, where the fire chamber is shewn surrounded by a double case or
lining. The space between the iron plates may thus be economically and
advantageously used as a water chamber or boiler for generating steam, which
may be made to enter direct into a separate coil of hot pipes, and ultimately

page_text: discharge itself into the working cylinder 25, having previously attained a very
high degree of expansive power in its passage through the heated pipes, and
assisting by its admixture with the heated gases in the cylinder to drive the
piston; the boiler must be furnished with a safety valve (placed outside the case),
and may be supplied by a small force pump connected with a water tank, which
may be worked by any of the usual contrivances. The steam must of course
be made to communicate direct with the cylinder instead of passing through
the chamber 27 or pump 28, and a separate convolution of hot pipes or
calorifere is preferred and recommended, as the steam pressure will not then
interfere with or retard the free circulation of the hot air and gases. 32 shews
a platform in front of the engine, furnished with a protecting rail, for the
convenience of the stoker or engineer, the latter having access to the valves
by means of suitable levers working through small openings in front of the
hot air chamber as before described, to enable him to control, stop, or reverse
the engine, as is now practised with respect to steam engines, and which being
well known, require no particular description, except that an additional valve
(also under the control of the engineer) should be placed on the air pipe 31,
opening outwards, to relieve the engine suddenly from the pressure of the
pump (when requisite); and if steam be employed, the last turn of the top
range of the steam pipe or calorifere may be furnished with a relief valve,
acting outside the hot air chamber. The whole of the relief valves may be
connected with and acted upon by the same lever and under the controul of the
engine driver, by means of which the piston 25 may be at any time iustan-
taneously relieved from the pressure, and all danger as regards accidents from
the onward motion of the train entirely removed, as the breaks will then
destroy the monientum it has acquired without being in any way counteracted
by the power of the engine. Now, it is obvious that this engine may be
worked with advantage by steam power alone, without the use of the refri-
gerator or air pumps, or the admixture of the expansive gases, before specified;
I therefore do not limit my claim to such admixture, but I recommend them
as being more economical than the generation of steam alone, as less fuel is
required than where steam only is employed; a shallow fire being sufficient
for producing the elastic vapours and gases, and for generating low-pressure
steam in smaller quantity, and the same fire also serves to heat the tubular
chamber or calorifere together with the cylinder. Now, it is evident that the
larger the quantity of atmospheric air admitted into the fire chamber (provided
a cooling effect is not produced), the greater the proportion of expansive gases
and vapours will be produced, and for this reason the furnace door should be
drilled, or provided with suitable apertures, for admitting a current of air over

page_text: the fire, as well as through the furnace bars, in the ordinary manner. The
currents of air are shewn by the arrows in Figs. 19 and 21, where the air is
seen to enter the ash-pit of the furnace both at the back and front; and further
openings may be made in the case of the hot air chamber above the fire door
both in front and at the back, as seen in Fig. 21, furnished with slides or
dampers to regulate the admission of air; by this means, in addition to the
nitrogen gas and carbonic oxide, which are the principal products of ordinary
combustion (from coke or charcoal), which should always be employed in this
engine, pit coal not being suitable on account of the smoke and bituminous
vapours, a large proportion of carbonic acid gas will then be formed in the
air chamber surrounding the calorifying pipes, which, in addition to its im-
parting a greater heat, from the more perfect combustion of the hydrogenous
and carburetted gases rising from the fuel, also possesses a greater expansive
power, and when cooled down (by the action of the refrigerator 27), are
susceptible of greater expansion when reheated on their admission into the
calorifere, and the mixed gases consequently possess greater elastic energy as
a motive power. Now, it is evident that the same effect will be produced by
admitting into the calorifere carbonic acid, hydrogen, or other expansive gases,
generated in a suitablo vessel independent of the engine; but though the
engineer may avail himself of these and similar means, they will not be found so
economical as the mode already described and recommended, as the gases are
there furnished by the atmosphere; and if sufficient oxygen be afforded by
means of the upper current of air, before referred to, these gases will be found
to form in sufficient quantity for the purposes required without any exterior
source of addition. Now, if the engine be worked without steam, it will be
found economical to construct the cases surrounding the furnaces and hot air
chamber double, with a space of about two inches between the inner and outer
cases, which, being properly closed at the top and bottom of the outer case,
will confine a stratum of air, and act as a non-conductor, in preventing the
radiation of heat, which will effect a great economy in the fuel; this will be
understood by reference to Fig. 20; and if steam be also employed in the way
already described, the space may be increased, and the outer case should be
thoroughly covered with wood, or other slow conductor or heat-retaining
substances, for the purpose of preserving the heat in the boiler and economising
the fuel, as before. The peculiar construction of the refrigerating chamber 27
affords a very extensive cooling surface, the closed chambers being each about
eight feet long by six feet in height, and about one and a quarter inches
wide internally, and the air spaces between the chambers from one and a half
to two inches, and by being placed in the line of traction a very powerful

page_text: refrigeration will be obtained, the open spaces constituting separate wind flucs;
cach of the metallic surfaces, being partially heated by the passage of the hot
gases and vapours through the interior, by expanding the air between them,
produces a partial vacuum, which the colder atmosphere without instantly
supplies, which keeps up a powerful and continuous refrigerating current.
The refrigerator may be economically constructed with very thin iron, zinc, or
other metallic plates, of about one-sixteenth of an inch in thickness, and as
this part of the apparatus will be subject to a very feeble pressure (being in
open communication with the chimney), the joints may be made with common
rivets, placing a packthread between the lapping of the plates, which will
ensure a sufficiently tight joint at a small expence, and may be strengthened
by iron pins passing across the close partitions or chambers internally, which
will also keep the sides of the plates at a proper distance; the cross pipes
(which may
be formed of short pieces of slight tubing) may be secured with
common solder, as the heat to be sustained is not sufficient to melt it, and is
much less expensive than brazing the joints. Now, as before observed, I am
aware that the desired refrigeration of the heated airs and gases may be
more or less obtained by a series of pipes, placed either vertically, horizontally,
or inclined; I do not therefore limit my claim to the use of the apparatus above
described, so long as the means employed are suitably contrived and arranged
for carrying out the principle and object above explained; but I prefer and
recommend the construction and mode above specified, as it affords a larger
cooling surface in a given space than any other mode I am acquainted with.
These improved engines are applicable to a great variety of uses, stationary as
well as locomotive, and may if desired be used as a steam engine without the
refrigerating chamber (27) or air pump (28), but the most economical and
effective mode is that which I have described.
Note. When employed as a stationary power (or in floating vessels) where
weight is not an objection, the refrigerator may advantageously be placed in
water, and used as a common condensor, and will be found superior to most
of the apparatus employed for that purpose on account of its large cooling
surface. The engine above described may be made of various sizes, according
to the purposes to which it is to be applied; a good medium for railway engines
with a single hot cylinder will be about two feet six inches by two feet in the
fire chamber, gradually reducing to the ordinary size of the funnel or chimney,
or with two hot cylinders, as in Fig. 21 furnace, three feet by two feet six inches,
the chimney reducing upward in proportion from the base of the cylinders;
refrigerators, as before stated, about eight feet by six feet, with ten to fifteen
closed chambers; diameter of driving wheel (33) about six feet eight inches

page_text: to seven feet; cylinder (25), ten to twelve inches internally, with three feet
stroke; cylinder (28), six to eight inches internal diameter, with two feet six
inches stroke. The precise size, however, of the cylinders will be regulated by
the constructing engineer, who may use one or more air pumps, at discretion.
The above proportions are merely given as examples, as the size of the engines
and the proportions of their several parts must in all cases be regulated by
the work they have to perform. I would also have it understood, that in
reference to the Drawings and Diagrams herewith given, that some of the
working parts (as in the drum I) are purposely exagerated or enlarged, in
order to give a better explanation of their internal construction and mode of
application.
Having now fully described and specified the particulars of this Invention
and improvements, and the mode of carrying the same into effect, I would
have it understood that I do not confine my claim to the sizes of the several
machines herein described, or to the dimensions of their separate parts, so long
as they are suitably arranged and constructed for carrying out the objects
herein set forth and described; but I claim,-
First, the use and construction of force pumps acting in a large piston when
communicating power and motion by a combination of levers, wheels, and
pinions, or by any of the means herein described and referred to, whether water,
oil, or other suitable fluid be employed.
Secondly, I claim the use and application of metallic springs acting as a motive
power in propelling machinery, and for imparting motion for locomotive and
other useful purposes, according to the principle and modes herein set forth.
Thirdly, I claim the construction and application of the steam, gas, vapour,
or air engine, according to the mode and modes herein referred to and described,
whether employed with or without steam, or with steam alone.
Fourthly, I claim the application of hydrogen, carbonic acid, and other
expansive gases as a motive power when expanded by heat in the mode or
modes described, whether a tubular or other suitable form of heating apparatus
be employed.
And, fifthly, I claim the general use and application of the hydrostatic,
hydraulic, and mechanical powers herein described, according to the mode and
modes herein referred to and explained, and of which I have given the best
description in my power.
In witness whereof, I, the said John Lionel Hood, have hereunto set
my hand and seal, this Third day of December, in the year of our
Lord One thousand eight hundred and forty-five.
J. L. (L.S.) HOOD.

page_text: AND BE IT REMEMBERED, that on the Third day of December, in the
ninth year of the reign of Her Majesty Queen Victoria, the said John Lionel
Hood came before our said Lady the Queen in Her Chancery, and acknow-
ledged the instrument aforesaid, and all and every thing therein contained
and specified, in form above written. And also the instrument aforesaid was
stamped, according to the tenor of the Statute made in the fifty-fifth year of
the reign of His late Majesty King George the Third.
Inrolled the Third dex of December. One thousand eight hundred and