CERTAIN IMPROVEMENTS IN THE STEAM ENGINE
Year: 1845

page_text: TO ALL AND SUNDRY TO WHOM THESE PRESENTS SHALL COME,
I, WILLIAM MCNAUGHT, of Number Twenty-six, Robertson Street, Glasgow,
in Scotland, Engineer, send greeting.
-
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Charter
of Donation, or Letters Patent, under the Great Seal of Great Britain, sealed
at Westminster, the Tenth day of December, in the ninth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William McNaught, my exors, adññiors, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said Wiliam M°Naught, my
exors, adiñors, and assigns, by ourselves or such other person or persons
as I or they shall appoint or agree with, and no others, from time to time
and at all times during the term of years therein expressed, shall lawfully
make, use, exercise, and vend, within that part of the United Kingdom of
Great Britain and Ireland called England, Her Dominion of Wales, and
Town of Berwick-upon-Tweed, and in Her Islands of Jersey, Guernsey,
Alderney, Sark, and Man, and also in all Her Colonies and Plantations
abroad, the Invention described in the said Letters Patent as follows, viz*,
"CERTAIN IMPROVEMENTS IN THE STEAM ENGINE;" in which said Letters Patent
it is provided that I, the said William McNaught, within the space of six
calendar months from the date of the said Letters Patent, cause a particular
description of the nature of the said Invention, and in what manner the same
is to be performed, by a writing under my hand and seal, to be enrolled in
Her Majesty's High Court of Chancery, as in and by the said Letters Patent,
reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the above proviso, I, the said
William McNaught, do hereby declare that my Invention relates to Certain
Improvements in the Steam Engine, which may be generally described as con-
sisting in, and arising from, the application of a non-condensing cylinder, as
well to condensing or low-pressure beam engines as to high-pressure beam
engines of the kind or construction presently in use. And in order that the
nature of the said Invention, and the manner in which the same is to be
performed or carried-into effect, may be more clearly ascertained and fully
understood, I will proceed to describe and explain. the same,.with-reference to
the Drawings hereunto annexed, that is to say :-
Figure 1 of the annexed Drawings represents a side elevation of a con-
densing beam engine of the common construction for land engines, with the
non-condensing cylinder A attached to the engine seat by means of a cast iron
frame (part of which is supposed to be removed to shew the valve gear, &c.,
of the engine), and attached to the working beam by means of the piston
rod (a) and link (b). The steam of high pressure is admitted into the valve
chest or nozzle (v) of the cylinder A at any convenient place. In the present
case it is admitted on the opposite side from that shewn in the Drawing, but
- not seen, as, it is covered or hid by the cylinder A and-its exhaust pipe (c, è).
After performing its duty in the usual manner in the cylinder A, it escapes into
..the valve chest or nozzle (n, n,) of the condensing cylinder B, by means of the
pipe (cc), which pipe-forms at once the exhaust pipe of the cylinder A and
the steam pipe of the cylinder B. (d) is the lever on the wyper or valve shaft,
connected to the valves of the cylinder B by the usual means, and worked by
the eccentric (f), connected by the rod (e) to the lever (9), which is fixed on
the upper shaft (y). Upon the lever (9) is fixed a stud (s), to which stud is
attached the rod (h), connected to the wyper or valve shaft (i, i,) of the
cylinder A. To this valve shaft the valves of the cylinder. A are connected by
:side rods in the usual way. By thus connecting the two wypers, or valve
.shafts, the valves of both cylinders perform their operations by means of one.
eccentric, and when the eccentric rod is lifted out of gear, or disconnected from
the stud (s) on the valve lever (9), both sets of valves are disconnected from
the eccentric, or are "out of gear.". And if one set of valves are moved by
band, the other set make a corresponding motion. (k) is a cross' head fixed on
the piston rod of the cylinder A, and connected to the cross head (1) by means
of side rods, one of which (m) is shewn in the Drawing. The cross head (?)
being thus connected to the piston rod of the cylinder A, any number of rods
may be attached to it for working the pumps to supply the engine and boilers
with water... (r) represents, one of these rods.: "(o) is the governor lever, con-

page_text: nected to the governor and governor valve of the cylinder A; and, in addition,
a valve may be put into the pipe (c, c), and so connected to the governor lever
as to close when the engine attains a speed beyond the maximum rate, which
valve, when closed, will have a powerful effect in reducing the speed of the
engine. As the piston of the cylinder A is proceeding on its downward stroke,
the steam is escaping from its under side, and impelling the piston of the
cylinder B on its upward stroke, and the reverse when the piston of the
cylinder A is proceeding on its upward stroke, that is to say, the steam escapes
from the upper side of the piston A, and impels the piston of the cylinder B on
its downward stroke.
•
Figure 2 represents a side elevation of a marine engine, with the small or
non-condensing cylinder A-attached to the engine seat, into which it is partly
sunk, so as to pass between the keelsons of the vessels, and thus allowing a
longer stroke in an engine of this form than would be obtained if the cylinder
A was fixed as high as the low-pressure cylinder B. The piston of the cylinder
A is connected to the side beams by the usual means of piston rod, cross head,
and side rods. (a) is the steam pipe for conveying the supply of steam to the
cylinder A, in which it performs its duty in the usual manner; after which it
passes, by means of the pipe (c) into the valve chest or nozzle of the con-
densing or low-pressure cylinder B, and is then used for impelling the piston of
the cylinder B in the manner already described in Figure 1; that is to say, as
the piston of the cylinder A is descending, the steam is escaping from its
under side and impelling the piston of the cylinder B on its upward stroke;
and as the piston of the cylinder A is ascending, the steam is escaping from
its upper side, and impelling the piston of the cylinder B on its downward
stroke. The side beam is connected to the crank by means of the con-
necting rod (h), which passes, with two side rods, over the cross head
and side rods of the cylinder A. The valves of this engine are worked and
connected in a similar manner to those of the engine already described in
Figure 1; thus t is a lever on the wyper shaft, which, in this engine, from
the relative position of the valves and eccentric, is more convenient to be
separate from the lever on which the eccentric gab stud is fixed. On this
lever t is fixed 'a stud for connecting the rod w-to the valve gear of the
cylinder A, as shewn in the Drawing.
'
From the description above given, with reference to the annexed Drawings, it
will be seen that my improvements consist in the application of a non-condens-
ing cylinder to the kind or description of condensing or low-pressure beam engines
presently used, and attaching or connecting such cylinder to the opposite end
of the working beam from-that on which the condensing-cylinder is connected,

page_text: thereby causing the steam, after being used in the usual way in the non-con-
densing cylinder, to pass into the nozzel of the condensing cylinder, and there
to be used for impelling the piston of the condensing cylinder, after which it
In this manner a great
escapes into the condenser in the usual way.
additional power is obtained without any additional consumption of fuel, while
at the same time the pressure on those parts of the engine which are subjected
to the greatest amount of strain is materially lessoned. In the common form
of beam engines, whether with double or single cylinders, the whole impelling
power of the engine is communicated to the one end of the working beam, &
given out at the other or opposite end, whereby the strain on the main centre
of the working beam, and all the parts connecting it with the building or
engine seat, is much greater than the strain on any other part of the engine.
This has been found to be a great practical disadvantage, and it is one which
will be in a great measure if not entirely obviated by my improvements, the prin-
pal object of the present Invention being as much as possible to equalize the
strain on the working beam, and to lessen that on the main centre and all the
parts connecting it with the building, engine seat, and framing, at the same time
that it will have the effect of increasing the power of the engine, of lessening
the consumption of fuel in proportion to the power produced, and by working
the steam expansively in the low-pressure cylinder a further saving of steam
may be effected, and consequently a proportional saving of fuel.
Having thus explained the nature of my Invention, &, with reference to
the annexed Drawings, described the manner in which the same is to be per-
formed or carried into effect, agreeably to the proviso of the said Letters Patent,
I claim as my Invention the application of a non-condensing cylinder for the
purposes herein-before set forth, and in doing so I would have it understood
that I do not limit myself to that particular mode or manner of applying.my
said Invention which is herein-before described. Thus, for example, although
in the Drawings to which that description refers the non-condensing cylinder
is represented in Figure 1 as being applied or attached to the working beam.
at a point about equal distance between the main centre of the beam and its
extreme end, & in Figure 2 as being applied or connected at the end of the
side beam, the self same or a similar result could be attained, with reference to
either of the two forms of engines, by applying or connecting the non-condens-
ing cylinder at any convenient part of the opposite end of the beam from that
on which the low-pressure cylinder is attached, & any such application
would equally be embraced by or comprehended under my Invention, & it
is to be understood as being claimed by me accordingly. Neither do I limit
myself to the application of a non-condensing cylinder to the present form

page_text: of condensing beam engines, although in the foregoing description & in the
relative Drawings such engines only have been exhibited and referred to by way
of illustration; but, on the contrary, I claim, as forming part of or embraced by
my said Invention, the application of a condensing cylinder to the common
form of high-pressure beam engines, and that either by the mode or manner
of working herein-before described, or after converting the high-pressure
cylinder into a condensing one by applying a small non-condensing cylinder to
the opposite end of the beam from that on which the one used as the con-
densing cylinder is applied and attached or connected at such point on that
opposite end as may be deemed most advantageous. And farther, and in
conclusion, I would have it understood that I do not claim as new any parts or
portions of the machinery or mechanism above described or referred to, by
means of which my improvements are to be carried into effect, taken by
themselves, & without reference to the objects or purposes of my said Inven-
tion, and the application thereof, as before explained.
In witness whereof, I have hereunto set my hand and seal at Glasgow,
the Twenty-sixth day of May, eighteen hundred and forty-six years.
Signed, sealed, and delivered by the
said William McNaught, before and
W (L.s.) M°NAUGHT.