CERTAIN IMPROVEMENTS IN THE METHOD OF WORKING ATMOSPHERIC RAILWAYS
Year: 1845

page_text: MAC DOUGALL'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
Mac Dougall, of Daisey Bank, in the Parish of Manchester, in the County of
Lancaster, 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 Seventeenth day of May, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Alexander Mac Dougall, my.exors, adiñors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said Alexander Mac Dougall,
my exors, admors, or assigns, or such others as I, the said Alexander
Mac Dougall, my exors, admors, and 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 Berwick-upon-Tweed, my Invention
of "CERTAIN IMPROVEMENTS IN THE METHOD OF WORKING ATMOSPHERIC RAILWAYS;"
in which said Letters Patent is contained a proviso, that I, the said Alexander
Mac Dougall, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, to be inrolled in
Her said 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
apnear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Alexander Mac Dougall, do hereby declare the nature of my Invention for
improvements in the method of working atmospheric railways consist, first in
a new and improved method of transmitting the motion of the piston to the
carriages to be moved or propelled; and, secondly, in a new and improved
method of producing the required vacuum to allow the atmospheric pressure
to move or propel such piston; and the manner in which my improvements
are to be performed and carried into effect will be seen by reference to the
annexed Drawings, and the following description. The scale to which the
Drawings are made is marked thereon, and the same letter or figure of
reference indicate the same part throughout the whole of the Drawings:--
The first part of my Invention, or that by which the motion of the piston is
transmitted to the carriage by a new and improved method, is represented in
various views, sections, and detached parts at Figures 1, 2, 3, and 4, and
consists of a traction pipe or tube furnished on the top side with a longitudinal
opening of a trough shape, proportioned to the size of the pipe; a section of
such pipe and trough is. represented by Figure 1, in which A is the pipe, and
B, the trough. The trough is furnished with a pliable substance which covers
the longitudinal opening of the tube, which covering is tinted red in the
Drawing, and may be attached to the flanches b, b, in the manner shewn in
the Drawing, or in any other manner that may be found convenient. The
substances suitable for the pliable covering are leather, caoutchouc, vulcanized
caoutchouc, macintosh cloth, oiled cloth; or others which are impervious to air.
and combine pliability with tenacity and durability may be used. The piston
is represented at C, Figure 3, suitable for the traction pipe A, and provided
with the pulley D, which is designed to raise the pliable covering into the
position, seen in Figure 2. The metallic guides d, d, are designed to prevent
the pulley D from vibrating, or at any time touching, the edges of the groove
during the traverse of the piston in the tube A. The wheels H, H, are intended
to bear the weight of the piston and its appendages, and to diminish the friction
on the interior of the tube, but they may be dispensed with. Figure 4
represents the carriage with one or more projections or arms, corresponding in
number with the pulleys D on the piston, and supporting the pulleys E, which
travel in the trough B of the traction pipe; these pulleys E. receive the
pressure from the pulleys D on the piston, and the motion given to the piston
by. the pressure. of atmosphere is thus communicated through the pliable
covering of the groove to the carriage with the projections, or arms thereto
attached. The pulleys E can be raised or lowered at pleasure by means of

page_text: the rack wheel placed at each end of the carriage; or the same may be effected
by means of a lever.
be
Another modification of this first part of my Invention consists in a method
of covering the groove or longitudinal opening in the pipe A with a flexible
metallic plate, which will admit of a variety of forms, but the one I prefer is
represented at Figure 5, Sheet 2; in this Figure the trough B is so formed as
to permit the metallic cover of the groove to be raised into the position
represented in Figure 6, but also to prevent it (or the part of the machine
connecting the piston with the carriage) rising above the position in which
they are there shewn. In addition to the pulleys D the piston is furnished
with an armature to connect it with the carriage, and through which an
opening is made to admit of the passage of the flexible metallic cover of the.
groove, as seen in elevation and plan at Figures 7 and 8. When the piston
is in motion the cover of the groove will be supported by the pulley D, which
will revolve under it, and greatly reduce the friction; or the armature may
dispensed with, and means of communicating the motion from a travelling
piston through a flexible covering, first described, may be employed. That
portion of the trough on which the cover of the groove rests may be furnished
with an unctious lining, or it may be lined with vulcanized caoutchouc or other
substance to render. the junction of the cover with the trough air-tight.
Figure 9 represents the carriage attached to the piston in the tube, and the
manner in which they are connected. It will be seen that the armature from
the piston is fitted into a similar armature from the carriage, and that thoy
may be connected or detached at pleasure by means of bolts at the command
of the person having charge of the carriage. The projection or armature of
the carriage may also be raised or lowered by means of the rack wheels placed
at each end of the carriage. It may not probably be necessary to furnish
more than one rack wheel to a carriage, but if two are supplied, the carriage
be worked in either direction without turning it.
may
The second part of my Invention consists in a new method of effecting the
removal of the air from the traction pipe, and the production of the roquisite
vacuum by means of a fan. Figure 10, Sheet 3, represents in section the form
of apparatus I prefer for this purpose; it consists of a wheel with tubular spaces
radiating from the centre, where the air is admitted from the traction pipe or
vacuum vessel to be exhausted; when this wheel is made to revolve, the air at
and about the centre will be thrown to the circumference through the tubular
spaces marked i, where it will be compressed till its elasticity is sufficient to
open
the valves K, K, through which it will pass into the external air, or if it
be found convenient to use compressed air, it may be conveyed into the traction

page_text: pipe behind the piston, or collected into a reservoir to be used for that purpose.
The outer portion L, L, in which the wheel M, M, is made to revolve, is
stationary, and is not an essential part of the machine except in cases whero
compressed air is required. Figure 11 is a section through the imaginary line
ac, a, see Figure 10, to shew the form of the axis Z, and the receiving box Y,
and also the hollow part of the axis through which the air passes; S is tho
covering, which may be of wood, iron, tin or other suitable material. Figure
18 is a bird's-eye view of the wheel or fan uncovered; Figure 12 is a front
elevation of the wheel covered; Figure 14 is a bird's-eye view of the same
covered in.
Having described my Invention for "Improvements in the method of
working atmospheric railways," and the manner in which the same is to be
performed and carried into effect, I wish it to be understood that I do not
confine myself to the details herein described, so long as the peculiar character
of any part of my Invention be retained; but what I claim as my Invention is,--
First, the improved method of constructing the traction pipe, with a pliable
covering to the groove, and the mode of communicating motion from a
travelling piston, through a pliable or flexible substance, for the propulsion of
carriages on atmospheric railways.
Second, the improved method of constructing the traction pipe with a.s
flexible metallic covering to the groove, and the mode of connecting the
carriages with the piston, and the communication of motion from the piston to
the carriages in the manner described.
And, third, the improved method of producing the requisite vacuum of
atmospheric railways by the use of a fan, the construction of which is well
known, and the peculiar construction of the machine for exhausting or.
exhausting and compressing air, described in the second part of my Invention. :
And lastly, I claim the application of compressed air behind the piston, in
conjunction with the vacuum produced before the piston as applied to.
atmospheric railways. All which being to the best of my knowledge and s
belief new, and never before used in that part of Her Majesty's dominions.
called England, and the Town of Berwick-upon-Tweed, I deliver this as my
true and faithful Specification of the same.
In witness whereof, I, the said Alexander Mac Dougall, have hereunto
set my hand and seal, this Thirteenth day of November, in the
of our Lord One thousand eight hundred and forty-five.
,
year
S
:
ALEXANDER (L.s.) Mc DOUGALL.

page_text: year
AND BE IT REMEMBERED, that on the Thirteenth day of November, in
the of our Lord 1845, the aforesaid Alexander Mac Dougall came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
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.
Enrolled the Seventeenth day of November, in the year of our Lord One
thousand eight hundred and forty-five.