A NEW METHOD OF RAISING STEAM FOR WORKING FIRE ENGINES
Year: 1756

page_text: TO ALL TO WHOMTHESE PRESENTS SHALL COME, JOHN
WRIGHT, of Lower Redbrooke, in the County of Gloucester, Refiner, sends
greeting.
WHEREAS His present Majesty King George the Second, by Letters
Patent, under the Great Seal of Great Britain, bearing date the Twenty-
seventh day of May last past, reciting that he, the said John Wright, had by
his petition to His Majesty represented that he had by long application and
many years experience in directing the building and working of great number
of furnaces of different structures found out and brought to perfection "A NEW
METHOD OF RAISING STEAM FOR WORKING FIRE ENGINES," whereby many collieries.
as well as tin, copper, and lead mines, that have been worked to so great a depth
as to be at present of little or no value to the proprietors, by reason of the great
expense of coal in draining them by fire engines in the method they are now
worked, might, by means of such Invention, be worked with very considerable
advantage to the publick in general and the proprietors in particular by the
much less quantity of coal rendered necessary for working such fire engines,
and that the said Invention would be also of great advantage in working fire
engines for raising water in the neighbourhood of London and elsewhere for
publick use, and tend to singular benefit in many mechanical opperations, and
praying His Majesty's Letters Patent for the sole use thereof, His Majesty did
thereby give and grant unto the said John Wright, his executors, administra-
tors and assigns, his especial licence, full power, sole priviledge and authority,
make, use, exercise, and vend his said Invention within England, Wales,
Barwick upon Tweed, and all His Majesties Plantations in America, to have,
hold, exercise, and enjoy the same for the term of fourteen years from the

page_text: date thereof; in which said Letters Patent is contained a provisoc, that if the
said John Wright should not particularly describe and ascertain the nature of the
said Invention and in what manner the same is to be performed, by an instru-
ment in writing under his hand and seal, and cause the same to be inrolled in
the High Court of Chancery within four kalendar months next after the date
of the said Letters Patent, that then the said Letters Patent and all advantages
thereby granted should cease and become void.
NOW KNOW YE, that the said John Wright, in pursuance and perform-
ance of the said provisoc, doth hereby describe and ascertain the nature of the
said Invention, and in what manner the same is to be performed, as follows
(that is to say):
The boiler is made of copper or iron plates hammered and rivetted together
in the ordinary way and form of boilers now in use for atmosphere engines
worked by steam of boiling water, but with the following difference, (viz',)
this boiler is heated with fire made to reverberate by the bottom of the boiler
being of a shape to form the arch or roof and inner side walls of a reverberating
furnace, and is placed over a hollow or open space of about ten feet long from
the bridge to the reverberatory, and eight feet wide in the middle or widest part,
five feet wide at the bridge, and six feet wide at the reverberatory, as in the
plan annexed, Figure 1. The bottom of the boiler is made sloping, and fixed
three feet high at the bridge and one foot high at the reverberatory above the
bottom of the hollow or open space through which the flame and hot air pass
from the fire-place or grate under the bottom of the boiler to the reverberatory,
as in Figures 2 & 5, 6, b. The flame and hot air are returned under a flanch or
elbow that projects from the outside of the boiler about one foot, and forms a
cavity between the brick work and the outside of the boiler of about fourteen
inches by twelve, as in Figures 3, 4, & 5, c, c, through which cavity they pass into
the chimney or stack, as in Figure 2, d. The hollow or open space is divided
into two flews or cavitys, as in Figures 1, & 5, b, b, which are twelve inches by nine
cach, and are contained of the same dimensions, one foot and a half upright, and
are there returned under the flanch or elbow before described. The bottom of the
boiler is made to descend in two trows or hollows, one on each sile the before-
mentioned hollow or open space, of about one foot wide and ten feet long each,
as in Figure 1, a, a. These trows or hollows are made curving, so as to form
the two sides of the said hollow or open space, and communicate with the
boiler, as in Figures 3, 4, & 5, a, a. The fire place or grate is about three
feet by two feet, and is divided from the said hollow or open space by a bridge
of about one foot six inches high and two foot six inches wide at the bottom,
and brought tapering up on each side to about one foot wide at the top, over
which bridge the flame passes under the bottom of the boiler, as in Figure 2, e.

page_text: Over the fire place and bridge another part of the boiler is fixed, the bottom
of which is made curving so as to form an arch of about six feet diameter, and
is joined to the other part already described with nails or rivetts, and at the
place that the two parts of the boiler are joined together a division is made
cross the boiler with a plate of copper or iron, Figure 2, f, f, to such height
as the boiler is to be filled with water when the engine is at work. The water
that supplys the boiler to make good what is evaporated in steam is conveyed
into that part of it that is fixed over the fire-place and bridge, and communicates
with the other part of the boiler over the top of this division, by which means
the coldest water is contained in that part of the boiler that is exposed to the
greatest heat of the fire. The dimensions of the fire-place and flews and of
the other parts of the boiler above described may be enlarged or contracted
according to the size of the engine that is to be worked by it, or the quality of
the coal that is to be burnt, these demensions being calculated for an engine
that is worked by a cilinder of about forty-five inches diameter, and the fire
to be made with coal that burns quick, and does not cake in the grate. The
boiler may likewise be made with or without a flanch, and the flews may be
conveyed both into one chimney or stack, as in the plan annexed, or into two
chimneys or stacks, one to receive each flew. By a boiler of the shape and
fixed in the manner above described it is apprehended a much larger surface
of water is exposed to the fire than by any other method that has been yet
practised, and consequently a larger quantity of steam will be produced with a
less consumption of fewell. And a further advantage may arise by this method
of working fire engines, as copper, tin, lead, iron oars, and other materials may
be calcined at the same time and with the same fire that works the engine, by
being placed in the hollow or open space under the bottom of the boiler.
In witness whereof, the said John Wright hath hereunto set his hand
and seal, the Fourteenth day of August, in the thirtieth year of the
reign of our Sovereign Lord George the Second, by the grace of God,
of Great Britain, France, and Ireland, King, Defender of the Faith,
and so forth, and in the year of our Lord One thousand seven hundred
and fifty-six.
Signed, sealed, and delivered, being
first duly stampt, in the presence
JOHN WRIGHT.

page_text: AND BE IT REMEMBERED, that on the Sixteenth day of August, in the
year bove written, the aforesaid John Wright came before our said Lord the
King in His Chancery, and acknowledged the writing aforesaid, and every
matter and thing therein contained, and specified in form above said, and the
said writing was stampt according to the Statute made in the Sixth
the reign of the late King William and Queen Mary, and so forth.
year of