AN IMPROVED METHOD OF CONSTRUCTING BOILERS FOR STEAM ENGINES
Year: 1827

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FRASER, of Houndsditch, in the City of London, Engineer, send greeting.
WHEREAS His present Majesty King George the Fourth, in and by His
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eleventh day of January last, for Himself, His heirs and
successors, did give and grant unto me, the said James Fraser, His special
licence, full power, sole privilege and authority, that I, the said James
Fraser, my executors, administrators, and assigns, and every of them, by
myself and themselves, or by my and their deputy or deputies, servants or
agents, or such others as I, the said James Fraser, my executors, adminis-
trators, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, usc, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVED
METHOD OF CONSTRUCTING BOILERS FOR STEAM ENGINES;" in which said Letters
Patent there is contained a proviso obliging me, the said James Fraser, by
an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the same
is to be performed, and to cause the same to be inrolled in His Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said recited Letters Patent, as in and by the same,
reference being thereto had, will more fully appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Fraser, do hereby proceed to describe the nature of my said Invention,
the principal feature of which is to surround a steam boiler or boilers
altogether or in part with a hollow case to contain water, which case should
have an internal space, of the width of three inches or more in proportion
to the size of the boiler. The line of water inside the main boiler to be line
of water in the case; sufficient room is to be left between the said case and
the said boiler or boilers for heat to pass between them. By this arrangement
the whole heat of the fires which issue from the flues in the interior of the
boiler or boilers, instead of passing direct into the shaft as at present, is
brought to act on the external surface of the boiler without injuring the
timbers of the vessel, ship, or boat, as will appear by the following
description:-
Place three flues in the interior of a boiler, two of which are for fires,
and these fires are to be made so near the sides of the boiler as just to admit of
space for cleaning these flues; proceed through the interior of the boiler from
front to back, or nearly so, as the maker may incline. In either case the flame
and heat is compelled to descend under the bottom of the boiler, which is to
be curved upwards like a waggon boiler bottom, to make room for the fluo
It is understood that the case is
between the case and the said boiler.
This boiler, with its
below the boiler bottom, as well as at the sides and end.
bottom curved upwards, is to be made to rest with its leg on the case, to
cut off all communication between the external sides and bottom flues, so that
the descending heat from the internal flues comes forward under the boiler,
nearly to the front under the fireplaces, at which place a part of the boiler
is rounded off, or the leg cut at each side, and a gore made to form a lateral
flue to allow the flame and heat to pass from the bottom to the sides, or in
other words, to pass to the flues between the case and the sides of the boiler;
the flues then proceed to the back of the boiler by the sides, and these side flues
are again bounded by the case, and both flues are thereby diverted at the back
into the third or centro flue in the interior of the boiler, and again return
nearly to the front through that flue, and then ascend into the shaft for the
purpose of draught. When the fires are first lit, a small fire is to be made in
the front of the third or last flue. To effect that end the bottom and sides of
the boiler or boilers are to be curved inwards like the common waggon boiler
for the express purpose of giving room for the flues both at sides and bottom
this lessens the water in tho boiler, and the case is also more compact. Ther
is such variety in the method of constructing flues that no claim is attempted
to be made for any, though there is considerable novelty in making the side

page_text: Hues re-enter the boiler by the centre flue. In land engines the flues may be
made to pass under the case as well as under the boiler, and thus occasion
much additional surface of flue, and consequently power, and a saving of fuel.
Any mechanic accustomed to make steam boilers will easily conceive the
necessary stoppage or check where the interual flues disgorge on the external
surface of the boiler, whether these flues descend under the bottom to pass to
the front where the lateral flues are, or whether the internal flues are brought
to act first on the external sides of the boiler, and made to pass by the sides
forward to the lateral flues, and back under the bottom, for without this
stoppage the whole contents of the internal flues would at once pass into the
centro flue if not compelled by the check to press to the lateral flues placed
nearly under the main fires. But as none of these can sweep the external
surface of the boiler without the assistance of the case to shield the ship from
fire, it is not necessary to describe numerous other arrangements, nor is it
requisite to point out the secondary uses of the case, such as heating water
prior to entering the main boiler, or the uses for which the steam of the said
case could be appropriated. Every engineer is capable of appreciating theso
matters; nor will he forget that if a boiler were to be the entire extent of the
engine room, and be about three feet square, with a flue in the middle,
sufficient room would be thus left for the engines in the centre, whilst one
third more surface of heat could be procured, and this again doubled by the
assistance of the case. It it evident also that the steam of the main boiler
will force the salt out of the case as easily as out of the main boiler. To
prevent the swag of water in the case, a partition in the middle will be of
great use, and it can be so contrived as to join the said case in two separate
parts at the said partition, and thus facilitating its entrance on board of ship
when there fitted to the boiler.
I therefore proceed to declare, that my Invention consists of a case to contain
water being applied to surround the external surface of boilers altogether if
required, or in part, leaving room between for flues, for the purpose of bringing
heat at a high temperature to act on the external surfaces of marine boilers
without endangering the ship timbers, thus economising fuel by an immense
enlargement of the surface of flue, and preventing the premature escape of heat
into the funnel or shaft. The said case ought to have an internal space of the
width of three inches, and should be fitted up to the line of water in the inside
of the internal boiler, leaving space above that for the steam. But although I
have specified three inches as the width of the internal space of the case, less
might answer; three inches, however, seem to me to be ample width for
ordinary purpose of sccurity, and for cleaning out. Room is to be left in the

page_text: Inrolled the same Eleventh day of July, in the year abovo written.