AN IMPROVED BOILER FOR GENERATING STEAM OR VAPOUR
Year: 1865

page_text: LETTERS PATENT to John Charles Wilson, of East India House, 5,
Lime Street, London, County of Middlesex, Civil and Mechanical
Engineer, for the Invention of "AN IMPROVED BOILER FOR GENERATING
STEAM OR VAPOUR."
Sealed the 12th June 1866, and dated the 14th December 1865.
PROVISIONAL SPECIFICATION left by the said John Charles Wilson
at the Office of the Commissioners of Patents, with his Petition, on the
14th December 1865.
I, JOHN CHARLES WILSON, of East India House, 5, Lime Street, London,
County of Middlesex, Civil and Mechanical Engineer, do hereby declare
the nature of the said Invention for "AN IMPROVED BOILER FOR GENERATING
STEAM OR VAPOUR," to be as follows:-
This Invention consists in a means of facilitating the conversion of water
into steam, or vapour by a new mode of causing a rapid circulation of the
water within the boiler: This object I accomplish as follows:-
I construct my boiler with an outer shell and inner fire-box in the usual
manner, preferring however the cylindrical vertical form; and I employ
small water tubes to bring the water or other liquid into contact with the heat
of the fire. Instead, however, of disposing these tubes so as to leave the end
ends open only to the water space of the boiler as at present, I have only
one end of my tubes open to the water space and the other open to the steam
space. At the same time the whole of that part of the tubes that is exposed
[Price 8d.1

page_text: to the action of the fire is filled with water, or, in practice, with a mixture
of water and steam. I wish it to be distinctly understood that no part of
said tubes exposed to the heat from the fire in my boiler is filled with steam
alone. Further, that end of the tubes which is open to the steam space is
only a few inches above the level of the surface of the water in the main part
of the boiler, and this is an essential point in my Invention.
The above being a particular description of my Invention, I now proceed to
explain its action as follows:-
The boiler being filled with water to within a few inches of that end of the
tubes which communicates with the steam space of the boiler (and which I
shall in future call the steam end), the water is of course at the same level
in the main part of the boiler and within the tubes, and remain so while the
boiler is cold. On the fire being lighted, however, that level is disturbed as
follows: The water within the tubes having imbibed a portion of the heat,
and being converted in globules of steam in the usual manner, these globules
immediately rise in the tubes and rush out through the steam. ends,
carrying along with them a portion of the hot water from within the
tubes, which falls down into the main water space of the boiler. There is
thus a double abstraction of water from within the tubes, viz., that which
is converted into steam and that which is carried over by the steam as
above described; this creates a momentary difference of level between the
surface of the water within the tubes and in the main water space of the
boiler, which is, however, immediately restored or attempted to be restored
by the greater pressure of the water at the highest level, a rapid circulation
through the tubes being thereby established.
..
One distinctive feature of this boiler is this, that the steam which is gene-
rated in the tubes is not again brought into contact with the comparatively
cold water in the main part of the boiler, but emerges at once into the steam
space.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Charles Wilson in the Great Seal Patent Office on
the 14th June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CHARLES WILSON, of East India House, 5, Lime Street, London, County of
Middlesex, Civil and Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December, in the year of our Lord

page_text: One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Charles Wilson, Her special licence that I, the said John
Charles Wilson, my executors, administrators, and assigns, or such others as
I, the said John Charles Wilson, 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 "Ax
IMPROVED BOILER FOR GENERATING STEAM OR VAPOUR," upon the condition
(amongst others) that I, the said John Charles Wilson, 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 John Charles Wilson, 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 follow-
ing statement:-
My Invention consists in a means of facilitating the conversion of water
into steam or vapour by a new mode of causing a rapid circulation of the water
within the boiler. This object I accomplish as follows:-
I construct my boiler with an outer shell and inner fire-box in the usual
manner (preferring the cylindrical vertical form), and I employ small water
tubes to bring the water or other liquid into contact with the heat of the fire.
Instead, however, of disposing these water tubes so as to leave their ends, as
at present, open to the water space of the boiler only, I construct and arrange
them so as to leave one end only open to the water space and the other to
the steam space, at the same time keeping that part of the said water tubes
which comes in contact with the heat of the fire filled with water (or in
practice with a mixture of water and steam). I wish it to be distinctly under-
stood that no part of my said water tubes exposed to the heat of the fire is
filled with steam alone. Further, those ends of my said water tubes. which
are open to the steam space of the boiler are only a few inches above the
level of the surface of the water in the main part of the boiler, and this is an
essential point in my Invention.
Figure of the accompanying Drawings is a section, and Figure 2 a plan,

page_text: shewing the manner in which I construct some of my said boilers of the vertical
cylindrical form; Figure 3 is a section of a Cornish or horizontal tubular
boiler, shewing the manner in which I construct my said boilers of that form.
Similar letters refer to similar parts in all the Figures.
A, A, are the tubes containing the water or other liquor to be heated or
evaporated, B being the end which is open to the water space only, and C the
end which is open to the steam space. D, D, are the tubes connecting the
ends C, C, with the steam space. E, E, is the level of the surface of the
water in the main part of the boiler. F is the fire-box, and G the grate bars;
H is the fire-box door; J, J, is the chimney; M, M, the steam space of the
boiler; N, N, the damper; and O, O, the opening from the fire-box into the
chimney; k is a fire-brick column suspended beneath the opening of the
chimney to prevent the flame going out at the chimney without first passing
through the rows of tubes; L, L, is the bottom of the water space, where
the water is comparatively still, and mud or sediment is collected. The boiler
being filled with water to about the level E, E, the water will of course be at
the same level in every part of the boiler, including the tubes; it will remain
the same while the boiler is cold, but on the application of heat the level will
be disturbed as follows:-The water in the tubes being converted into globules
of steam, these rise into the steam space M, M, through the ends of the
tubes C, D, and in so doing (as they rush out with some force) they carry
along with them additional portions of water, which fall down again into the
main water space below. There is thus a double abstraction of water from
within the tubes, viz., that which is converted into steam and that which is
carried over along with the steam. The level of the water in the boiler is in
consequence disturbed, the level in the tubes C, D, inclining to fall below that
of E, E, but the natural flow of the water down the tubes (from E, E, through
the ends B, B, to the ends C, D,) causes the level to be immediately restored,
and this motion continuing as long as the heat is applied the result is a rapid
and continuous circulation of the hot water through the tubes, with a corre
sponding powerful generation of steam. It will be observed that the steam
once generated in the tubes does not again pass through a body of compara
tively cold water, as in the present boilers, but emerges at once into the steam
space.
"
It is not essential that the said tubes should be double with both end
fixed in the top or crown" of the fire-box or fine, as shewn in Figure 1, b
they may be single tubes with the lower or water ends fixed through the side
of the fire-box or flue, or instead of projecting down into the fire-box, a
shewn in Figure 1, the said water tubes may be passed through the mai

page_text: part of the boiler surrounded by flame tubes, or flame tubes may be passed
through the main part of the boiler surrounded by my said water tubes, or
both arrangements may be combined; my said water tubes in each case con-
sisting of tubes with one end open to the water space and the other to the
steam space of the main part of the boiler. Figures 4, 5, & 6 of the Drawings
hereunto annexed illustrate these arrangements. I consider the latter an
excellent form. In the arrangement shewn in Figure 1 the tubes are fixed
into the tube plate in the usual manner, and the ends D, D, are loose pieces
fitted tight into the tubes after they have been fixed into the tube plate. The
other parts of the boiler are made as customary.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my improvement in
boilers, constructing the water tubes with one end only open to the water space
of the main part of the boiler, and the other end open to the steam space;
no part of said water tubes exposed to the heat of the fire being filled with
steam alone, all substantially in manner herein-before described.
In witness whereof, I, the said John Charles Wilson, have hereunto set
my hand and seal, this Fourteenth day of June, One thousand eight
hundred and sixty-six.
JOHN C. WILSON. (L.S.)