CERTAIN IMPROVEMENTS IN ENGINES OR MACHINES FOR OBTAINING AND APPLYING MOTIVE POWER
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, JAMES
NASMYTH, of Arundel Street, in the County of Middlesex, Gentleman, 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 Twenty-ninth day of April, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
James Nasmyth, Her especial license, full power, sole privilege and authority,
that I, the said James Nasmyth, my executors, administrators, and assigns, and
such others as I, the said James Nasmyth, 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, and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, my
Invention of "CERTAIN IMPROVEMENTS IN ENGINES OR MACHINES FOR OBTAINING
AND APPLYING MOTIVE POWER;" in which said Letters Patent is contained a
proviso obliging me, the said James Nasmyth, 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 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
James Nasmyth, do hereby declare that the nature of my 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)
These Improvements in Engines or Machines for Obtaining, and Applying
Motive Power consist principally in three particulars, which mainly apply to
atmospheric railways, although some parts of them are intended to be used,
independently of railways, as motive power for other purposes. I shall, how-
ever, in order to explain my Inventions, clearly exhibit them in the accom-
panying Drawings and following description in connection with a pneumatic
railway, and afterwards state what are the particular features of improvement
in engines or machines for obtaining and applying motive power which
constitute the novel features intended to be claimed by me.
Fig. 1 is a longitudinal section taken vertically through a portion of a tube
A, A, of any suitable diameter, in which a piston B is intended to be worked
by pneumatic pressure, for the purpose of producing the traction of carriages
upon a railway constructed above it. C, C, is a long piston rod, extending to
a great distance, both behind and before the piston: The tube A, A, may be
of any length, say a mile, in which case the rod C C; should be of two 'miles
extent. Near each extremity of the tube there is to be a standard or stretcher
D, with an aperture and stuffing box a in the centre for the 'passage of the
piston rod C, and beyond these stretchers, at each ultimate extremity of the
tube, there are hung upon hinges a pair of doors E, which, when shut, are 'to
close the end of the tube A perfectly air-tight. These doors are seen in an end
view of the tube represented at Fig. 2, and in the horizontal view of a portion
of the end of the tube at Fig. 3.: It is intended when the doors E, E, are
closed to produce a vacuumor.exhaustion of air in that part of the tube
which is before the piston by some convenient means, either by the condensa-
tion of steam therein, or by an air pump, or other contrivances as already
known, or by the means which I shall herein-after explain, as part of my
improvements in obtaining motive power. When this vacuum is obtained in
the tube before the piston, the doors E, E, behind the piston must' be thrown
open to give free access to the atmospheric air, by. which the piston is to be
impelled forward through the exhausted part of the tube. In order to support
the piston rod C, C, as the piston moves onward: through the tube, there are
a series of guide rollers placed at suitable distances apart along the interior of
the tube, one of which is shewn at F in Fig 1. These guide rollers are

page_text: mounted each on an axle-in tlie upper ends of pendulous tumbling levers G,
which levers hang upon axles-b, mounted in recesses H, formed in the under
part of the tube; and at the lower end of each of these pendulous levers there
is affixed by an arm c, a plummet 'or-bob-d, which by its gravity keeps the
tumbling lever erect, and the guide' roller Funder the piston rod C; but
when the piston B has to pass, any one of these guide. rollers F an inclined
plane e, placed-in front of the piston (see Fig. 1), comes in contact with the
roller F and throws it and its tumbling lever down into the recess H, where
the roller F remains whilst the piston passes over it, and when the piston has
passed the pendulous tumbling lever is made again to resume its erect position
by the gravity of the plummet or bob d, which brings the guide roller under the
piston rod as before, and thereby supports it. The manner in which the
pendulous levers are mounted in the tube will be-best seen in the transverse
vertical section of the tube shewn at Fig: 4, and the partial longitudinal repre-
sentation of the outside of the tube at Fig. 5. The tumbling lever G, as before
said, moves within the tube upon an axle b, the pivots of which are inserted
into the sides of the recess H; and to one end of the axle b, passed through
the side of the recess, the bent arm c-is affixed, which carries the plummet at
the outer side of the projection which is formed by the recess, a spring e is
attached, having a small notch in it for the purpose of catching hold of a pin
on the arin c, and thereby holding the pendulum or tumbling lever G firm and
erect. On the piston approaching the extremity of the tube, two horizontal
rods f; extending from the front of the piston, strike against the doors E, E,
and force them open, but before this takes place that end of the tube before
the advancing piston, which was in a state of exhaustion, must be permitted to
receive a portion of atmospheric air by the opening of a valve toward the end
of the tube, which may be done by any convenient apparatus acted upon by
the advancing piston, or the piston rod, or otherwise. It has been said that
the tube A, A, may be a mile long; I propose to construct a series of. these
tubes along the line of a railway at two miles distance from each other, and
totally unconnected. To any precise lengths of tubes I do not, however,
intend to limit my Invention; but desire it to be observed, that, for the carry-
ing out of my object in the way I intend, it is necessary that the spaces
between the ends. of any two tubes in the range or longitudinal series, should
be twice the length of the tubes themselves. Supposing that the length of the
tube A, A, should be one mile, then the length of the piston rod C, C, should be
two. miles, and the piston be affixed to the rod as at B, in the middle; that is,
at one mile from each outer extremity of the piston rod.
Fig. 6 represents one of the outer extremities of the piston rod C, to

page_text: which is attached an upright arm K; a similar arm is also to be attached
to the reverse end of the piston rod at the distance of two miles; and to
the upper parts of these arms K, K, the ends of a longitudinal rod L,
of similar length to the piston rod, is to be made fast. This rod L is
supported by a series of grooved rollers M, mounted on axles, in carriages
fixed at suitable distances apart along the upper surface of the tube A,
as shewn in Figures 1 and 4. It will hence be perceived that, as the
piston B passes along within the tube A, the piston rod C, C, by means of
connections to the ends of the parallel rod L, on the outside of the tube, will
cause the rod L to pass along over the rollers M, M, M, simultaneously with
the progress of the piston, and that if a railway carriage or carriages be at-
tached to the rod L, they will travel along the rail at the same speed that the
piston passes along the exhausted tube. Having provided for the support of the
piston rod C, C, as it passes along the interior of the tube, and for the support of
the rod L, L, as it travels along the outside of the tube, I now proceed to show
the manner in which the extended length of the piston rod C is to be borne up
before and after it has passed through the tube. For this purpose I mount a
series of guide rollers, in suitable frames, at convenient distances apart along
the centre of the line of railway, between the tubes, and coincident with them.
The manner in which I propose to construct these guide rollers and their ap-
pendages is shewn at Fig. 7, which represents a transverse clevation, as they
would I appear standing across the railway. The piston rod is shewn in trans-
verse section at C, and N is the guide roller on the upper surface of which
the piston rod runs. This roller is mounted upon an axle turning in standards
g, g, and above it there is another roller P, which, by pressing upon the piston
rod C, keeps it down in the groove of the roller N. The axle h, upon which the
roller P turns, is an arm or horizontal lever, mounted upon a vertical shaft i, i,
supported by one of the standards g and the bracket frame k, the outer ex-
tremity of the arm or lever h bearing upon the standard b. As the piston B
progresses through the tube A, the upright arm k (see Fig. 6), which connects
the extremities of the horizontal rods C and L, must be allowed to pass freely
along the line of railway over the scries of supporting rollers N (Fig. 7). It
is, therefore, necessary that the rollers P, which press the piston rod down
upon the guide rollers N, should be removed out of the way at such times as
the arm K is about to pass. This is done by the upright arm K striking
against the roller P, which causes it and its axle or lever h to turn horizontally
upon the vertical shaft i, and, as soon as the upright arm K. has passed a
double spiral spring upon the shaft i, immediately brings the roller P and its
axle into their former position, as shewn in Fig. 7. I have described the long

page_text: piston rod C and the parallel rod Labove as rigid rods or bars, which they may
be, and perhaps would answer best if made tubular, like gas pipes; but I do
not intend to confine myself to the employment of such rods or tubes, as wire
ropes or chains might suit my purpose in place of rods. In such case I should
form an endless band of wire rope or chain, and pass it over two pullies situate
at three miles apart, the vacuum tube A, A, occupying one mile in the middle
of the line between the two pullies; and the piston being attached to this endless
band or chain within the tube, and the railway carriage to the endless band or
chain on the outside of the tube, as the piston moved in one direction the
carriage would be drawn in the opposite.
Having now explained the manner in which I impel carriages along rail-
roads, by means of their attachment to an upper rod or band parallel to and
connected with the piston working by atmospheric pressure in an exhausted
tube, I think it necessary to observe, that I do not intend to confine myself to
tubes A, of one mile long, or to any other particular lengths of tubes, but that
whatever may be the lengths of the tubes a station or stopping place must be
at the commencement and end of every tube, and also at the points reached
by the ends of the horizontal rods C and L. For instance, I will suppose that
from my first station or starting place the commencement of the tube A shall
be one mile distant, the piston B being brought to that end of the tube, the
extremity of the piston rod C and the rod L, with their connecting arm K,
will extend back one mile to the said first station. The railway carriage or
carriages at the station being then attached to the nether end of the rod L,
near the connecting arm K, and the piston B put in motion, when the piston
has reached the further extremity of the tube the carriage or carriages will
have been drawn forward one mile, that is, to the second station at the com-
mencement of the tube. The carriages must then be released from their
attachment to the rod L, and by producing an exhaustion in the tube behind
the piston, the rods with the piston will by pneumatic pressure be conducted
back again, as in other atmospheric railways. This being done, the carriages
are to be again connected to the rod L, but now near its middle, just over the
situation of the piston, when by the forward stroke of the piston, as before,
the carriages will be impelled onward another mile to the third station, at the
further extremity of the tube A. Here again the carriages are to be released
from their attachment to the rod L, and the piston being sent back as before,
the carriages are to be, lastly, attached to the further end of the rod L, at the
extremity of the tube, when by the next advance of the piston the carriages
will be sent forward on the railway another mile, that is, to the fourth station.
The carriages have now arrived at that part of the line where the tube and the

page_text: rods described cease to operate them. Another tube and its appendages exactly
similar in construction' to those already described; then takes up the carriage
or train of carriages in the way before explained. Hence it will be perceived
that the train is conducted forward from station to station, and that the tubes
containing the working piston, instead of being continuous, as in other
atmospheric railways,, require, to occupy only one third of the length of the
railway; being placed at intervals apart, the distance of which should be double
that of the lengths of the respective tubes...
· ་
1
..That part of my Invention which respects, obtaining motive power I will
now explain, and shew it also in connection with a pneumatic railway. .At
Fig. 6, Qrepresents a large wheel turning vertically upon a shaft m; on the
periphery of this wheel the piston rod. C bears as. it passes, and by the friction
of;contact between these two surfaces, the passing piston rod will cause the
wheel, to revolve... In order to promote the friction, another wheel R,
mounted upon a compound lever n, n, having its fulcrum at p, is brought
down and made to. bear upon the upper surface of the piston rod C, and a
weight q, placed upon the arm r of the compound lever, causes the wheel to
press with greater force and increase the friction; a pinion s, formed on the
boss of the wheel Q, takes into the teeth of another wheel S, which last men-
tioned wheel may be, employed through a crank upon its axle, or any other
contrivance, to work the air pumps for exhausting the tube A, or as a motive
power for any other purposes. When the air pumps are not required to be
in action, the friction may be taken off by raising the wheel R, which is done
by throwing back the arm.r, and allowing it to rest against the stop t.
Having now. described my improvements in engines or machines for obtain-
ing and applying motive power, as adapted to railways worked by pneumatic
or atmospheric pressure, I, in conclusion, desire it to be understood, that the
three particular.features. of novelty to which I have above alluded, and which I
desire to claim under the present Letters Patent, are,
. Firstly, the construction and working of atmospheric railways by the employ-
ment of series of comparatively short disconnected vacuum tubes,, placed at
intervals apart, and operating. independently of each other, in place of the long
connected tubes heretofore used for the purpose of obtaining the traction of
carriages by atmospheric pressure;
Secondly, connecting an external rod.or rope with the travelling piston
For the purpose of attaching the carriages. thereto, and obtaining traction
from the centre of the working. piston; which contrivance may also be applied
to communicate motive power for other purposes;
Thirdly, applying the motive power obtained by the friction of the piston rod,

page_text: or of the traction rod or rope, against the peripheries of revolving surfaces for
working the air pumps of pneumatic 'railways, and for any other purpose to
which such motive power may be applicable;
And lastly, I also claim the introduction of apparatus for supporting the ex-
tended piston rod within the tube in order to preserve its horizontal position.
In witness whereof, I, the said James Nasmyth, have hereunto set my
hand and seal, this Twenty-third day of October, in the year of our
Lord One thousand eight hundred and forty-five.