IMPROVEMENTS IN WORKING ATMOSPHERIC, RAILWAYS, AND IN. MACHINERY FOR CONSTRUCTING THE APPARATUS EMPLOYED THEREIN
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES.
NASMYTH, of Patricroft, in the Parish of Eccles, in the County of Lancaster,
Engineer, and CHARLES MAY; of Ipswich, in the County of Suffolk, Engineer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-second day of October, in the eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said James Nasmyth and Charles May, Her especial licence, full power, sole.
privilege and authority, that we, the said James Nasmyth and Charles May,
our exors, adors, or assigns, or such others as we, the said James Nasmyth
and Charles May, our exors, admors, or assigns, should at any time agree with,
and no
others, from time to time and at all times thereafter, 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, our.
Invention of "IMPROVEMENTS IN WORKING ATMOSPHERIC, RAILWAYS, AND IN.
MACHINERY FOR CONSTRUCTING THE APPARATUS EMPLOYED THEREIN;" in which
said Letters Patent is contained a proviso. that we, the said James Nas-
myth and Charles May, or one of us, shall cause a particular description
of the nature of our. said Invention, and in what manner the same is to.
be perforined, to be inrolled in Her, said Majesty's. High Court of Chan-
cery within six calendar. months next and immediately after the date of the
・

page_text: 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, we, the said
James Nasmyth and Charles May, do hereby declare that the nature of our
said Invention, and the manner in which the same is to be performed, are
fully described and ascertained in and by the following statement thereof,
reference being had to the Drawings hereunto annexed, and to the figures
and letters marked thereon, that is to say:-
Our Invention relates,-
First, to the means of obtaining the requisite vacuum in the traction pipe
of atmospheric railways. And,
Secondly, our Invention relates to the working of brakes for retarding a
carriage or carriages used on railways by causing the brakes used to be
brought into action by the pressure of the air into a vacuum.
And in order that our Invention may be most fully understood, and readily
carried into effect, we will proceed to describe the means pursued by us.
It is well known that in working atmospheric railways as at present
practised the requisite vacuum is obtained by air pumps, which are of very
small size compared with the contents of the traction pipe, which is to be
exhausted thereby, and it is well known that the working of air pumps on
a large scale is very expensive. We would at the outset state that we believe
it to be very important that in order to ensure the well-closing of the
longitudinal valve in the traction pipe that a larger quantity of the air may
be instantaneously withdrawn therefrom, so as to bring the atmosphere to
press more forcibly on to the valve, and thus to ensure its instantaneous
closing, otherwise any stiffness in the valve may not be overcome by the very
partial vacuity produced by the first part of the time of the working of the air
pumps, hence leakage at such parts of the valve where the same is not well
and completely closed.
Now, the first part of our Invention, in addition to the advantages derivable
from the comparatively small cost of the apparatus used when contrasted
with the cost of steam engines and air pumps, and also in addition to the
advantages derivable from the simplicity of the apparatus, and its not being
hable to get out of order, it will be found that owing to the peculiar character
of the apparatus that a greater effect or extent of vacuum can be instantane-
ously obtained in the traction tube, and a certainty of more quickly closing
the valve; so as to prevent leakage consequent on any want of power of the
outer atmosphere owing to the partial state of vacuum in the traction pipe;
aud this apparatus may, if thought desirable, be used as an aid to air pumps,

page_text: being then continued by the working of air pumps.
DESCRIPTION OF THE DRAWINGS.
Figure 4 represents a general view of the apparatus. It consists of two
upright air-tight vessels A and B, and also an air-tight vessel C, these three
vessels forming a set, so that in extending the power of the apparatus the
same set of three vessels may be repeated any number of times, so as to
extend its power and capabilities either by number or by size of the vessels, as
may be found most convenient. In order to describe the nature of the action
of this apparatus, and the mauner in which the vacuum is produced for the
before-named purpose, we shall, in the first place, suppose that steam is
introduced from a suitable boiler by the pipes E*, E*, E*, so as to enter
into the vessels A, B, C; and as the steam enters at the upper end of each
vessel, it will (on account of its less specific gravity as compared with the air
contained in the vessels, first, on entering, occupy the upper part of the said
vessel, and as it continues to flow in will depress and force out all the air
contained by the vessels A, B, C, the air in question being discharged through
the valves at G, H, and I. So soon as this is accomplished, all further influx
of steam is arrested, and the valve at I, which admits a stream of cold water
from the cistern Y, is opened, so as to let a jet of water flow from Y into
the condenser, which not only instantly condenses all the steam in C but also
in B, the valve V being at that time in the position seen in the Drawings,
Figures 4 and 1, thus producing a vacuum in the vessel B. The instant this
is the case the valve K is opened to the traction tube, and a portion of the
air contained in it is abstracted through the opening or passage M. The
valve K is then closed by any suitable means, the vessel B containing rarefied
air and A containing steam. The valve V is next moved into the position
(seen at Figure 2), by which a free communication is established between
the vessels B and A, and the steam in A being of greater pressure than tho
rarified air in B a portion of steam will flow from A into B; an equilibrium
being thus established, the valve V moved into the position as seen at
Figure 3, and the steam in A is condensed by the contact of water flowing
into the condenser C, which condenser, as often as is requisite, is cleared
of water and air by admitting steam at its pipe E*, the jet of water for the
time being stopped, and a discharge valve at the bottom opened. The valve
L is then opened, and a further portion of air is drawn drawn through the
opening M into A. While this is being accomplished, the valve V being
in the position as seen in Figure 8, a further supply of steam is again

page_text: admitted from the boiler into the vessel B, which, together with the steam
which has been received from A, expels the air from B, as before described in
the first operation. The same movement of the valve V which admits the
steam to flow from the boiler into the vessel B opens a communication
between A and C, and then the remainder of the steam contained in A is
condensed. The valve L is then opened, and a further portion of air is
withdrawn from the traction tube. The valve V is again moved, so that the
steam is cut off from B and a communication established between B and A;
a portion of the steam from B rushes into A, then by a further movement of
the valve V a communication is formed between B and C, by which B is a
second time exhausted, and so on in this manner continually until the required
exhaustion is produced in the traction tube, the operation being continued
during the passage of the trains along the traction tube, if required. In order
to render the exhausting apparatus self-acting, the following is a description of
the arrangement adopted-A tank or vessel of water Z is placed over the
discharge valve G, within which is placed the gasometer T, having a small
aperture in the top of it at t; to the top of this gasometer is attached a rod R,
having a rack pitched into the circumference of the wheel O, working loose
on its axis and carrying a pall taking into the teeth of a ratched wheel O¹ on
the same axis, and attached to which and revolving with it is a wheel
working into a rack on the rod of the steam valve V. It will be seen by this
arrangement that the air as it is discharged from the vessel A passes rapidly
through the water in Z, and not having a sufficient exit at t will elevate the
gasometer T and flow out from under the edge of T. The suspension of the
gasometer T will continue just so long as air is being discharged under it, but
as soon as all the air is expelled from the vessel A, and steam begins
to pass out into the water, the gasometer begins to sink down, the air which
sustained it leaking out at t, and as it sinks, by means of the rack wheel and
pall connected with it, the valve V is drawn or moved into the opposite
position, namely, from the position as in Figure 1 to that seen in Figure 3,
which inverts the order of the action of the steam with respect to the vessels A
and B. A similar self-acting apparatus is placed on the side next to vessel B,
which reciprocates in like manner to that just described at side of A. In
order to prevent the undue mingling of the air and steam, the latter is
admitted into the upper part of the vessels A and B, and a diaphragm with
perforations is placed below the opening at which the steam enters which
causes the steam to descend in a quiet manner.
The second part of our Invention consists in applying the pressure of the
atmosphere to the movement of a piston acting on the brakes of carriages,

page_text: order. to arrest the progress of such carriages on atmospheric railways; and
we accomplish this as follows:-Upon the carriage, or some part of the
framing thereof, we place an air-tight vessel capable of sustaining the pressure
of the atmosphere when exhausted of air. We exhaust this vessel either by
a tube connected with the exhausted traction tube, or by means of a small
pump worked by an excentric upon the axle of the carriage, or by both these
combined. We also provide a cylinder fitted with a piston moving air-tight
therein, one side of which piston is open to the atmosphere, the piston rod
being attached to a lever acting upon the brake. A tube connects the
cylinder with the vacuum chamber, in which tube is a stopcock under the
controul of the conductor, who has simply to open the cock and form a
communication between the cylinder and the vacuum chamber, where the
piston, being pressed inwards by the atmosphere, acts with force upon the
lever of the brake. The stopcock referred to may be so made as by a further
movement to admit air behind the piston, and a spring or weight being
attached thereto drives the piston back, so as to release the brake. The
foregoing description is for the case of a single carriage traversing an
atmospheric railway, but where many carriages are used we propose to have a
much larger vessel for the vacuum chamber, with a proportionate air pump to
connect the cylinders of each carriage with the vacuum chamber by means of
a tube of flexible air-tight material, having branches, so that when the
conductor opens the vacuum chamber to this tube all the pistons are instantly
drawn inwards, and the brake of every carriage in the train brought into
action simultaneously.
Having thus described the nature of our Invention, and the manner in
which the same is to be performed, we would have it understood that we do
not confine ourselves to the details herein described, so long as the peculiar
character of either part of our Invention be retained.
But what we
claim is,―
First, the mode of obtaining vacuum in the traction pipes of atmospheric
railways, as herein described.
And, secondly, we claim the mode of working brakes of carriages on
atmospheric railways by the pressure of into vacuum.
In witness whereof, I, the said Charles May, have hereunto set my
hand and seal, this Twenty-second day of April, in the year of our
Lord One thousand eight hundred and forty-five.
CHARLES (L.S.) MAY..

page_text: AND BE IT REMEMBERED, that on the Twenty-second day of April,
in the year of our Lord 1845, the aforesaid Charles May came before
our said Lady the Queen in Her Chancery, and acknowledged the Specifi-
cation 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 Statutes made for that purpose.
Enrolled the Twenty-second day of April, in the year of our Lord One
thousand eight hundred and forty-five.