CERTAIN IMPROVE- MENTS IN STEAM ENGINES."
Year: 1859

page_text: LETTERS PATENT to Francis Herbert Wenham, of Brixton, in the
County of Surrey, Engineer, for the Invention of "CERTAIN IMPROVE-
MENTS IN STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Francis Herbert Wenham
at the Office of the Commissioners of Patents, with his Petition, on the
29th November 1859.
I, FRANCIS HERBERT WENHAM, of Brixton, in the County of Surrey,
Engineer, do hereby declare the nature of the said Invention for "CERTAIN
IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
This Invention is chiefly applicable to marine condensing engines worked
by the expansion of high-pressure steam in the following manner :-A pinion
on the crank shaft of a high-pressure engine or engines is geared on to the
main shaft of the condensing engines either by a spur or bevil wheel, causing
the high-pressure engines to make a greater number of strokes or revolutions
than the condensing engines. Steam of a high pressure is led direct from the
boiler to the non-condensing engines, after having been there worked ex-
pansively it is returned into a series of pipes placed in the chimney, known as
a "superheater," being thus surcharged with heat, it is next carried back to
the cylinders of the condensing engines, expanded again, and exausted into

page_text: the condenser. The hot water drawn from the condenser by the air pump is
conveyed into the top of a chamber containing a number of channels, passages,
or pipes, through the interior of which an ascending current of cold water flows
by the action of a pump, or otherwise. The hot water is thus cooled in its
descent through the refrigerator, and used again for condensing the steam by
being drawn through an injection pipe into the condenser in the usual way.
In the case of an iron boat, instead of the refrigerator above described, the
water from the hot well of the air pump may be cooled and returned for
injection by being discharged into channels or troughs led about inside the
bottom of the boat below the water line, such troughs having sheet iron or
metal lids. The boiler must be fed with the water from the condenser, and to
replenish waste a small still is required.
Having thus described the nature and action of my Invention, I would have
it understood that I make no claim to the parts separately, but what I claim
is, the combination of high-pressure and condensing engines for marine
purposes, working in connection at different velocities, and superheating the
steam after leaving the first engine, together with its condensation by cooling
the injection water in the manner I have described, or by the ordinary modes
of surface condensation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Herbert Wenham in the Great Seal Patent Office
on the 23rd May 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
HERBERT WENHAM, of Brixton, in the County of Surrey, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of November, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Francis Herbert Wenham, Her special licence that I, the said Francis
Herbert Wenham, my executors, administrators, and assigns, or such others
as I, the said Francis Herbert Wenham, 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

page_text: "CERTAIN IMPROVEMENTS IN STEAM ENGINES," upon the condition, (amongst
others) that I, the said Francis Herbert Wenham, my executors or adminis-
trators, 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 Francis Herbert Wenham, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
This Invention is chiefly applicable to marine condensing engines worked
by the expansion of high-pressure steam in the following manner:-A pinion
on a crank shaft, actuated by one or more high-pressure cylinders, is geared
on to the main shaft of the condensing engines, either by a spur or bevil
wheel, the high-pressure engines thus making a greater number of strokes or
revolutions than the condensing engines. Steam of a high pressure is led
direct from the boiler to the non-condensing engines, after having been there
worked expansively it is returned into a series of pipes placed in the smoke-
box, known as a "superheater;" being thus surcharged with heat, it is next
carried to the cylinders of the condensing engines, expanded again by the
usual gear for cutting off at various parts of the stroke of the piston, and
finally exhausted into the condenser. The hot water drawn out of the con-
denser by the air pump is conveyed into the top of a chamber containing a
number of channels, passages, or pipes, through the interior of which an
ascending current of cold water flows by the action of a pump, or otherwise.
The hot water is thus cooled in its descent through the refrigerator, and con-
tinually used again for condensing the steam, by being drawn through an
injection pipe, and conducted into the condenser in the usual way. In the
case of an iron boat, instead of the refrigerator above described, the water
from the hot well of the air pump may be cooled and returned for injection,
by being discharged into channels or troughs led about inside the bottom of
the boat below the water line, such troughs having sheet iron or metal lids.
The boiler must be fed with the water from the condenser, and to replenish
waste a small still will be required.
Having thus described the nature and action of my Invention, I would
have it understood that I make no claim to the parts separately; but what I
claim is, the combination of high-pressure and condensing engines for marine

page_text: purposes, working in connection at different velocities, and superheating the
steam in its passage between high and low-pressure cylinders after having
been worked in the former, together with its final condensation by cooling the
water from the hot well by passing it through a refrigerator and using it for
injection, in the manner I have described.
In witness whereof, I, the said Francis Herbert Wenham, have here-
unto set my hand and seal, this Twenty-third day of May, in the year
of our Lord One thousand eight hundred and sixty.
F. H. WENHAM. (L.S.)