AN IMPROVEMENT OR IMPROVE- MENTS IN THE CONSTRUCTION OF FURNACES, BY WHICH THEY CONSUME THEIR OWN SMOKE
Year: 1828

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
GILBERTSON, of Hertford, in the County of Hertford, Grocer, do send greeting.
WHEREAS His present most Excellent Majesty George the Fourth by His
Letters Patent under the Great Seal of the United Kingdom of Great Britain
and Ireland, bearing date at Westminster, the Fifteenth day of January now
last past, did give and grant unto me, the said James Gilbertson, my executors,
administrators, and assigns, Ilis special licence, full power, sole privilege and
authority, that I, the said James Gilbertson, my executors, administrators, and
assigns, should and lawfully might make, use, exercise, and vend, during the
term of years therein expressed, within that part of the said United Kingdom
of Great Britain and Ireland called England, His Dominion of Wales, and
Town of Berwick upon Tweed, my Invention of "AN IMPROVEMENT OR IMPROVE-
MENTS IN THE CONSTRUCTION OF FURNACES, BY WHICH THEY CONSUME THEIR OWN
SMOKE;" in which said Letters Patent there is contained a proviso obliging me,
the said James Gilbertson, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, aud
in what manner the same is to be performed, and to cause the same to be
enrolled in His Majesty's High Court of Chancery within two calendar months
next and immediately after the date of the said recited Letters Patent, as in and
by the same, reference being thereunto had, may more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Gilbertson, do hereby declare that my said Invention of an Improvement
or Improvements in the Construction of Furnaces by which they Consume their
own Smoke is fully described and ascertained in manner and form following,
that is to say-
My said Invention consists in the construction of furnaces with the sides of
them made of hollow plates of iron, in order that a current of air may pass
through them, and in its course become heated and then be discharged into a
cavity or ash pit formed at the back of the fire, whence, proceeding through a
grating affixed at the top of this cavity, it comes in contact with the smoke and
flame of the fire, and causes an almost complete combustion of the whole of the
fuel employed. In large furnaces, where a great quantity of air is necessary,
I make a portion or the whole of the bars hollow, but I do not claim any
Invention in this application of hollow bars, only as in aid of the effect to be
produced by the hollow plates at the sides. The accompanying Drawings in
the margin of these Presents, and the following description thereof, will more
particularly ascertain and determine the precise nature of my Invention; that
is to say, Fig. 1 is a section of a furnace constructed according to my improve-
ment or improvements, from A to B in the Plan, Fig. 2; and Figure 3 is
another section, from C to 1; the same letters refer to the same parts in each
Figure. A, the boiler; B, furnace; C, the hollow side plates; D, the furnace
bars; E, the bearing bars; F, the air cavity or ash pit at the back of the
furnace, having a door I for the purpose of clearing out the dust and ashes that
will accumulate; G, the air grating at the top of the air cavity, to prevent the
fuel from falling into the air cavity, and to diffuse the heated air freely among
the smoke of the fire; E, an iron plate, or other suitable material, projecting
a few inches over the grating to direct the heated air from the cavity on to the
fire of the furnace. Now I do not mean to confine myself to the precise form
and construction of furnace exhibited in the Drawings in the margin of these
Presents, as it is evident various modification may be requisite to adapt my
Invention to different kinds and forms of furnaces.
In witness whereof, I, the said James Gilbertson, have hereunto set my
hand and seal, this Thirteenth day of March, One thousand eight
hundred and twenty-eight.
JAMES (L.s.) GILBERTSON.

page_text: AND BE IT REMEMBERED, that on the same Thirteenth day of March,
in the year above mentioned, the aforesaid James Gilbertson came before our
Lord the King, in His Chancery, and acknowledged the Specification afore-
said, and all and everything therein contained, in form above written. And
also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.