IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1858

page_text: LETTERS PATENT to Edward Humphrys, of Deptford, Engineer, for the
Invention of "IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
Sealed the 6th May 1859, and dated the 10th November 1858.
PROVISIONAL SPECIFICATION left by the said Edward Humphrys at
the Office of the Commissioners of Patents, with his Petition, on the
10th November 1858.
I, EDWARD HUMPHRYS, of Deptford, Engineer, do hereby declare the nature
of the Invention for "IMPROVEMENTS IN STEAM ENGINES AND BOILERS," to be
as follows:-
This Invention has for its object improvements in steam engines and boilers.
In arranging steam engines for propelling vessels by means of screw propellers
I combine with ordinary low-pressure cylinders, fixed in a horizontal or inverted
position, other cylinders of smaller size, which are to work at a higher pressure
than the low-pressure cylinder, and in connection with it, in the manner well
known as Wolf's system; the piston rods of the low and of the high-pressure
cylinders are so coupled together as to convey the power to the shaft through
a single connecting rod, and they are enclosed together in a steam jacket.
Before the steam is admitted to the high-pressure cylinders it is superheated
by passing it through heating apparatus.
In arranging locomotive engines such as are employed on common roads, I

page_text: apply a pair of engines to each driving wheel, so that either wheel may turn
independently of the other, and assume the speed due to any curve in which
the engine may have to move; the steam cylinders of such engines I place
within the boiler or smoke box, and I surround the moving parts of the
engines with a cistern which is filled with lubricating material, so that the
moving parts may be immersed therein. I also make the tube case of
locomotive boilers of a rectangular form, in lieu of the cylindrical form
heretofore ordinarily employed, and I strengthen the same with stays similar
to those employed within the fire box.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Humphrys in the Great Seal Patent Office on the
10th May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
HUMPHRYS, of Deptford, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Edward Humphrys, Her special licence that I, the said Edward
Humphrys, my executors, administrators, and assigns, or such others as I,
the said Edward Humphrys, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "Iм-
PROVEMENTS IN STEAM ENGINES AND BOILERS," upon the condition (amongst
others) that I, the said Edward Humphrys, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same. was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward Humphrys, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-

page_text: This Invention has for its object improvements in steam engines and
boilers. In arranging steam engines for propelling vessels by means of screw
propellers, I combine with ordinary low-pressure cylinders, fixed in a horizontal
or inverted position, other cylinders of smaller size, which are to work at a
higher pressure than the low-pressure cylinder, and in connection with it, in
the manner well known as Wolf's system; the piston rods of the low and
of the high-pressure cylinders are so coupled together as to convey the power
to the shaft through a single connecting rod, and they are enclosed together in
a steam jacket. Before the steam is admitted to the high-pressure cylinders
it is superheated by passing it through heating apparatus.
Figure 1 of the annexed Drawing shews a vertical section of one of a pair
of engines suitable for driving a screw propeller, and arranged according to
this part of my Invention; and Figure 2 a section taken at the line A, A,
Fig. 1. a is the larger or low-pressure cylinder, and 6 is the smaller or
high-pressure cylinder mounted on the top of the cylinder a; each of the
cylinders contains a piston, and these pistons are carried by a piston rod c
which is common to the two pistons; the rod c is connected to and drives the
crank d by a connecting rod. On the crank shaft are mounted the eccentrics
e, which by means of a single rod work the two valves f and g. The rod has
on it a piston e¹, which works in the cylinder e, and divides the valve boxes of
the two cylinders a and b. The valve f admits steam from the valve box h to
the cylinder b, and it also directs the steam leaving the cylinder 6 into the
pipe i, which conducts it into the valve boxj of the larger cylinder a. The
valve g regulates the passage of the steam coming from the cylinder 6 into the
cylinder a, and it also directs its passage from this cylinder to the condensor.
I prefer that the steam should be superheated before it is admitted to the
cylinder 6; the superheating may be effected in any convenient manner as
heretofore. The condensor consists of two rectangular cases k, one only being
shown in Figure 1, the other being removed; these cases contain tubes
passing in a vertical direction from end to end of them; to these tubes the
exhaust steam is admitted, and it is condensed by a current of cold water
caused to flow through the cases k, and in contact with the exterior of the
tubes by a centrifugal pump or otherwise. 1, 1, are two air pumps, which are
worked by rods passing direct from the pistons of the air pumps to the piston
in the cylinder a, and which pass through stuffing boxes in the cover of the
cylinder a. On the side of one of the air pumps is formed a guide m for the
head of the piston rod c. The cylinders a and b are surrounded by a steam
jacket n; the portion of this jacket that surrounds the cylinder a is composed
of wrought-iron plates bolted to ribs cast on the cylinder, as is shown, and that
l

page_text: part of the jacket which surrounds the cylinder 6 is made of wrought-iron
plates rivetted together, so as to form a cover, which drops over the cylinder
and is bolted to the top of the jacket of the cylinder a. I prefer to supply the
jacket with steam direct from the boiler without previously superheating it.
In the cover of the cylinder a is a man hole, by which the cylinder may
be entered for the purpose of examining and repairing the stuffing box
between it and the high-pressure cylinder b.
I would remark, that although in the arrangement shown both the pistons
are mounted on the same rod, this is not necessarily the case, as the pistons
may have separate rods, and yet be so connected together as to convey the
power to the shaft by one connecting rod.
In the engine shown in the Drawing the cylinders are inverted, but
horizontal engines may readily be constructed, having a similar arrangement
of parts.
In arranging locomotive engines, such as are employed on common roads, I
apply a pair of engines to each driving wheel, so that either wheel may turn
independently of the other, and assume the speed due to any curve in which
the engine may have to move; the steam cylinders of such engines I place
within the boiler or smoke box, and I surround the moving parts of the
engines with a cistern which is filled with lubricating materials, so that the
moving parts may be immersed therein.
In carrying out this part of my Invention, each of the two driving wheels
of a locomotive engine (suitable for running at a comparatively slow speed on a
common road, and suitable for drawing after them other carriages loaded with
heavy weights) has a separate axis, on which is a pinion which gears into a
cog wheel on its driving or running wheel. Each of these axes is driven by
two steam engines, the piston rods of each are connected by suitable connecting
rods to two cranks on the axis, and at the ends of each of the pairs of steam
cylinders is formed a cistern, within which the cranks, excentric, connecting
piston, and valve rods work; the axes driven by the engine pass through
suitable stuffing boxes in the sides of the cisterns, which are kept sufficiently
full of oil or lubricating fluid to cover the moving parts above-mentioned.
I also make the tube case of locomotive boilers of rectangular form, in lieu
of the cylindrical form heretofore ordinarily employed, and I strengthen the
same with stays similar to those. employed within the fire box; these stays
pass from top to bottom and from side to side of the case, and are employed
in such number as to give the amount of strength required; the stays thus
divide the space interior of the tube case into a number of rectangular parts
through each of which several tubes pass longitudinally of the case, as in an

page_text: ordinary locomotive boiler, and the tubes serve both as flues and to stay the
ends of the tube case as heretofore.
In witness whereof, I, the said Edward Humphrys, have hereunto set
my hand and seal, this Tenth day of May, in the year of our Lord
One thousand eight hundred and fifty-nine.
EDWARD HUMPHRYS. (L.S.)