CERTAIN NEWLY IMPROVED METHODS OF CON- STRUCTING FURNACES OR FIRE-PLACES TOR HEATING, BOILING, OR EVAPORATING OF WATER AND OTHER LIQUIDS, WHICH ARE APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES; AND ALSO FOR HEATING, MELTING, AND SMELTING OF METALS AND THEIR ORES, WHERELY GREATER EFFECTS ARE PRODUCED FROM THE FUEL, AND THE SMOKE IS IN A GREAT MEASURE PREVENTED OR CONSUMED
Year: 1785

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
WATT, of Birmingham, in the County of Warwick, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Fourteenth day of June, in the twenty-fifth year of His reign,
did give and grant to me, the said James Watt, His especial licence, full
power, sole privilege and authority, that I, the said James Watt, my exors,
adiñors, and assigns, should and lawfully might, during the term of years
therein expressed, make, use, exercise, and vend, throughout that part of
Great Britain called England, His Dominion of Wales, and town of Berwick
upon Tweed, my Invention of "CERTAIN NEWLY IMPROVED METHODS OF CON-
STRUCTING FURNACES OR FIRE-PLACES TOR HEATING, BOILING, OR EVAPORATING OF
WATER AND OTHER LIQUIDS, WHICH ARE APPLICABLE TO STEAM ENGINES AND OTHER
PURPOSES; AND ALSO FOR HEATING, MELTING, AND SMELTING OF METALS AND
THEIR ORES, WHERELY GREATER EFFECTS ARE PRODUCED FROM THE FUEL, AND
THE SMOKE IS IN A GREAT MEASURE PREVENTED OR CONSUMED;" in which said
recited Letters Patent is contained a proviso obliging me, the said James
Watt, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, by an instrument in writing
under my hand and seal, and to cause the same to be inrolled in His Majesty's
High Court of Chancery within one calendar month next and immediate'y
after the date of the said Letters Patent, as in and by the said Letters Patent

page_text: and the Statute in that behalf made, relation being thereunto respectively had,
may more at large appear.
NOW KNOW YE, that in compliance with the said proviso, and in pur-
suance of the said Statute, I, the said James Watt, do hereby declare that
the following is a particular description of the nature of my said Invention,
and in what manner the same is to be performed (that is to say) :-
My said newly improved methods of constructing furnaces or fire-places
consist in causing the smoak or flame of the fresh fuel in its way to the flues
or chimney to pass together with a current of fresh air through, over, or among
fuel which has already ceased to smoke, or which is converted into coaks, char-
coal, or cinders, and which is intensely hot, by which means the smoak and
grosser parts of the flame, by coming into close contact with or by being
brought near unto the said intensely hot fuel, and by being mixed with the
current of fresh or unburnt air, are consumed or converted into heat, or
into pure flame, free from smoak. I put this in practice, first by stopping up
every avenue or passage to the chimney or flues, except such as are left in the
interstices of the fuel by placing the fresh fuel above or nearer to the external
air than that which is already converted into coaks or charcoal, and by con-
structing the fire-places in such manner that the flame and the air which
animates the fire must pass downwards or laterally or horizontally through the
burning fuel, and pass from the lower part or internal end or side of the fire-
place to the flues or chimney. In some cases, after the flame has past
through the burning fuel, I cause it to pass through a very hot funnel, flue, or
oven before it comes to the bottom of the boiler, or to the part of the furnace
where it is proposed to melt metal, or perform other office, by which means the
smoke is still more effectually consumed. In other cases I cause the flame to
pass immediately from the fire-place into the space under a boiler, or into the
bed of a
melting or other furnace. The Drawing, Figure first, shews a section
of a fire engine boiler and its furnace or fire-place (which I have chosen for
an example of the application of this new method to the heating and evapo-
rating of water). (A, A,) is the boiler, which may be made of any form suitable
to its use. (B, B,) is a flue surrounding the boiler as usual. (C) is the uptake
or passage from the space under the boiler to the flues. (D, D,) is a funnel or
flue for the flame to come from the fire place to the boiler. (E, E,) is a place to
contain the ashes, and F is a door to take them out at, which must be kept
continually shut during the time of working. (G, H,) is the fire-place; the
fresh fuel is put in at G, and gradually comes down as the fuel below con-
The part at (H) is very hot, being filled with the coaks or coals
which have ceased to smoke. (J) is an opening or openings to admit fresh air
sumes.

page_text: and regulate the fire. K is a door into the space under the boiler, which
being opened admits air and stops the draught of the chimney when the
operation is wanted to cease. Figure 2 is a section of the same fire-place in
the other direction, in which (M, M,) is the back of the fire-place; L, the brick
arch on which the fuel lies; and (E, E,) the ash hole. Figure 3 is an outside
view of the same fire-place, shewing the air holes J, J, and the ash hole door F;
and Figure 4 is a plan of the same, with part of the boiler seating taken in
the line,, of Figure 1. The dotted lines represent the flues, and the darts
point out the direction of the flame. The fire is first kindled upon the brick
arch L, L, and when well lighted more fuel is gradually added until it is filled
up to (G), and care is taken to leave proper interstices for the air to pass either.
among the fuel or between the fuel and the front wall (N), and as much air is
admitted at (J, J,) as can be done without causing the smoak to ascend per-
pendicularly from G, which it will do if too much air is admitted at (J, J).
The dimensions of this fire-place are shewn by the scale, and are properly
adjusted for burning about eighty-four pounds' weight of coals in an hour;
where greater or lesser quantities are required to be burnt, the furnaces
must be enlarged or diminished accordingly, or if much greater, more furnaces
than one must be employed. Figure 5 represents this new fire-place as
applied to a furnace for melting iron and other metals, and constructed
without the funnel or perpendicular flue D, D, in Figure 1. N.B.-The
same letters refer to the same parts in all the preceding Figures. I also con-
struct these new fire-places so that the part G, H, lies sloping or horizontal,
and otherwise vary the figure or form and proportions of the same; but in all
cases the principle is the same, the fresh or raw fuel being placed next the
external air, and so that the smoak or flame passes over or through the coaked
or charred part of the fuel. I also occasionally cover the opening (G), and
cause the air to enter only or principally at (J, J); secondly, in some
cases I place the fresh fuel on a grate as usual, as at (A, A, Figure 6), and
beyond that grate, at or near the place where the flame passes into the flues
or chimneys, I place another smaller grate (B), on which I maintain a fire of
charcoal, coaks, or coals which have been previously burnt until they have
ceased to smoak, which, by giving intense heat and admitting some fresh air,
consumes the smoak of the first fire.
Lastly, be it remembered that my said new Invention consists only in the
method of consuming the smoak and increasing the heat by causing the smoak
and flame of the fresh fuel to pass through very hot funnels or pipes, or among,
through, or near fuel which is intensely hot, and which has ceased to smoak,
and by mixing it with fresh air when in these circumstances, and in the form

page_text: and nature of the fire-places herein mentioned, described, and delineated, the
boilers and other parts of the furnaces being such as are in common use.
And be it also remembered that these new invented fire-places are applicable
to furnaces for almost every use or purpose.
In witness whereof, I have hereunto set my hand and seal, this Eighth
day of July, in the year of our Lord One thousand seven hundred
and eighty-five.
Inrolled the Ninth day of July, in the year of our Lord One thousand
seven hundred and eighty-five.