CERTAIN IMPROVEMENTS IN BOILERS FOR GENERATING STEAM
Year: 1834

page_text: TO ALL
PRESEN
COME,
HUMAS
SEARLE, of Coleman Street, in the City of London, Merchant, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eleventh day of October, in the fifth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Thomas Searle, His especial licence, full power, sole privilege and authority,
that I, the said Thomas Searle, my exors, admors, and assigns, or such others
as I, the said Thomas Searle, my exors, adññiors, or assigns, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick upon
Tweed, the Invention of "CERTAIN IMPROVEMENTS IN BOILERS FOR GENERATING
STEAM," communicated to me by a certain foreigner resident abroad; in
which said Letters Patent is contained a proviso that I, the said Thomas
Searle, shall cause a particular description of the nature of the said Invention,
and in what manner the same is to be performed, to be inrolled in His
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 thercunto had, will more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Searle, do hereby declare the nature of the said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following description thereof, reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
The Invention consists of a peculiar arrangement of pipes or tubes within a
boiler, for the production of a circulation of the water contained therein, and
thus more advantageously applying the heat in the generation of steam.
DESCRIPTION OF THE DRAWING.
Figure 1 represents a boiler constructed according to the Invention. Figure
2 is a section of Figure 1, whereby the arrangement of the circulating tubes
or pipes within the flue will be clearly seen. Figure 3 is a tranverse section
of the flue. Figure 4 shows a plan of the covering of the flue; and Figure 5
represents the manner of affixing-the circulating tubes or pipes. In each of
these Figures the same letters indicate similar parts; a being the outer cylinder
of the boiler, and 6 the inner cylinder, which constitutes the main flue from
the furnace; c is a third cylinder, and constitutes the principal circulating tube
or pipe, as into this inner pipe c the whole of the water flows in the course of
its circulation, and rising to the surface gives off steam; the water then de-
scending, and again receiving heat, passes again through the branch circulating
tubes or pipes d, and thence into the principal tube c, as will be more fully de-
scribed hereafter. The tubes or pipes d, d, it will be seen, are affixed to the
cylinder b, and to the principal circulating tube c, as will be evident on inspecting
the various Figures; e is the fire-place or furnace, which it is preferred should
be lined with fire brick; f is the steam pipe to convey the steam to the engine,
or to any other purpose for which it is intended; g is the safety valve; h, h,
are flues proceeding from the main flue to the chimney i.
Having thus described the various parts of the boiler, with the improvements
applied thereto, I will describe the manner of action. Fire being lighted in
the furnace, the heat thereof will first come in contact with the diagonal tubes
or pipes d, and will heat the water contained therein; the consequence of which
will be that the water will expand, and becoming thereby, bulk for bulk, lighter
than the other part of the water contained in the boiler, such heated water
will rise upwards in the direction of the arrows, and a similar effect will take
place in the other tubes d. The water from all of which, as it becomes heated,
will flow into the principal circulating tube c, and ascend to the top, and give
off' so much as is converted into steam, whilst the remaining particles of

page_text: water will flow off to the sides of the boiler, and descend again to become
heated in passing through the tubes or pipes d, d, and thus will a constant
circulation be kept up within the boiler, and the heat generated in the fur-
nace be more economically applied; and at the same time, in case of impurities
being contained in the water, the same will be deposited at the lower part
of the boiler, where the same, not being materially acted on by the fire owing
to the fire brick, such lower part of the boiler will not be injured by the deposit
taking place there; and it will be evident, that by having a pipe and cock
conveniently placed, the sediment may from time to time be blown out. I would
here remark that it has not been thought necessary to show the requisite means
for supplying the boiler with water, nor for regulating the quantity; these have
been omitted in order to prevent complexity of drawing, but the same will
readily be supplied by an ordinary workman capable of performing the other
parts of the work.
Having now described the nature of the Invention as communicated to me
from a certain foreigner residing abroad, I would have it understood that I do
not claim the causing of the water to circulate in a steam boiler, various con-
trivances for that purpose having been before used. But I do hereby declare
that the improvements claimed under the above recited Letters Patent consist
in the application and combination of the circulating pipes or tubes c, d; d,
within the flue of a boiler, such flue being itself within the boiler as above
described, whereby an advantageous circulation of water will take place.
In witness whereof, I, the said Thomas Searle, have hereunto set my
hand and seal, this Tenth day of April, in the year of our Lord One
thousand eight hundred and thirty-five.
THO. (L.S.) SEARLE.
AND BE IT REMEMBERED, that on the Tenth day of April, in the
year of our Lord 1835, the aforesaid Thomas Scarle came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above