AN IMPROVEMENT OR IMPROVEMENTS IN THE BUILDING AND ERECTING ROOFS OR UPPER PARTS OF FURNACES USED FOR THE SMELTING OF COPPER AND OTHER ORES, OR ANY OF THEIR METALS, OR FOR ANY OTHER PURPOSE REQUIRING STRONG FIRES
Year: 1817

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HARRY, of Morriston, near Swansea, in the County of Glamorgan, Smelter
of Copper Ores, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Third day of October,
in the fifty-seventh year of His reign, give and grant unto me, the said
William Harry, my exors, adñiors, and assigns, His especial licence, full
power, sole privilege and authority, that I, the said William Harry, my exors,
adñiors, and assigns, should and lawfully might, during the term of years
therein expressed, make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVEMENT
OR IMPROVEMENTS IN THE BUILDING AND ERECTING ROOFS OR UPPER PARTS OF
FURNACES USED FOR THE SMELTING OF COPPER AND OTHER ORES, OR ANY OF THEIR
METALS, OR FOR ANY OTHER PURPOSE REQUIRING STRONG FIRES;" in which said
Letters Patent is contained a proviso that if I, the said William Harry,
shall not particularly 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 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 Letters Patent, that then the said Letters Patent,
and all liberties and advantages whatsoever thereby granted, shall utterly
cease, determine, and become void, as in and by the same, relation 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
William Harry, do hereby describe and ascertain the nature of my said
improvement, and the manner in which the same is to be performed, by the
following description thereof, reference being had to the Drawings annexed
(that is to say):
That my improvement _doth consist in a new method of forming, erecting,
or constructing, and of upholding or supporting until it be formed and
hardened, a roof or upper part of any furnace, of any shape or size what-
soever, requiring a roof or upper part, and in which it is necessary to
apply the heat of strong fires or otherwise, and which said roof or upper part
is composed of such cement or cements, composition or compositions, as on
being exposed to a certain gradual or other heat shall become baked or
The
hardened into one solid, compact, strong, durable, and uniform mass.
cement or cements, composition or compositions, of which the roof or upper
part is to be formed, may be made with fire clay, fire sand, fire earth, whole
or pieces of fire bricks reduced into small particles by any convenient process,
and mixed with fire clay, or any other material or materials possessing the
properties herein-before described; but the substance which I have found best
adapted for the purpose, and the adoption of which I therefore generally
recommend, is a certain clay called the Dinas fire clay, which may be pro-
cured at Neath, in the said county of Glamorgan. The Dinas fire clay, or
such other material or materials possessing the properties herein-before
described, of which the roof or upper part of the furnace is to be performed,
must be reduced by pounding, grinding, or any other suitable means, so small
as to be capable of being passed through a screen or sieve of one fourth of
an inch mesh, and must then be mixed with as much water as will form it
into a stiff pulp of the consistence of the common mortar used by masons,
which is done by frequent mixing, beating, or turning, until it becomes smoothe
and fine, and of the consistence beforo mentioned. The furnace must be
previously prepared for the reception of the roof or upper part in the follow-
ing manner, that is to say:-The casing and the sides, see Figures 1, 2,
having been made in the usual manner and with the ordinary materials, a
center of wood, iron, or any other suitable substance (but I prefer wood)
must be fixed in the same manner as when the furnace roof is to be built
with fire brick in the ordinary way. Upon this center an arch must be
turned, A, A, A, Figure 3, of brick, stone, sheet iron, copper (in which two
latter cases the center should also be of metal), or any other substance which
will bear the heat of strong fires, but I prefer brick for reasons which will
herein-after appear. When made of brick the arch A, A, A, Figure 3, should

page_text: manner.
be about four and a half inches thick, and the bricks of which the same is
made should be worked in cement, made in the usual manner with the best
fire clay. I abut this arch A, A, A, Figure 3, against the sides, as repre-
sented at B, B, Figure 2, and not against the casing. The arch A, A, A,
Figure 3, extends from the back part of the grate G to the reverberatory
arch M, Figure 8, which said arch M is supposed to have been previously
made, as also the stack or chimney C, D, E, F, Figure 3, in the usual
The top of the arch A, A, A, Figure 3, I afterwards make even
or smooth with any suitable material, but I prefer the fire-clay cement, such
as is in general use. The furnace being thus prepared for the reception of
the roof, the Dinas fire clay (for such 1 prefer) mixed in the manner and to
the consistence before described, should be worked and well incorporated upon
the arch A, A, A, Figure 3, until the whole of the said arch shall be covered
with the same to the thickness of eight inches, more or less. The whole must
now remain untouched for about two days, until the clay or other material
of which the roof is composed be sufficiently dried or hardened to bear
bracing or cramping in the usual manner without the braces or cramps sink-
ing into it. The furnace being then very carefully braced or cramped in the
usual manner, the wooden center should be removed from under the arch
A, A, A, Figure 3, (if the center be of metal it must remain during the
process of baking the roof), and very small fire kindled in the fireplace door-
way, Figure 1, which should be gradually increased for about a week or
more if required, until the clay or other material forming the roof has become
perfectly dry and hard, when the furnace may be heated to any degree
required and worked in the usual manner. Should any cracks appear in the
roof during the progress of its formation, or at any time afterwards, such
cracks should be immediately filled with a liquid cement (I prefer that made
of the best fire clay). After the furnace has been worked for a short time the
arch A, A, A, Figure 3, if made of brick, will be destroyed by the heat, when
it will crumble away and expose the hard, compact, smooth surface of the
clay or other materials of which the roof is composed to the fire. This pro-
perty, together with its cheapness, renders brick the most suitable material
for the purpose described; besides, metal being a better conductor of heat than
brick, the heat is not conveyed to the clay so gradually in the baking through
the former as through the latter medium, whereby the roof is more apt to
crack in this part of the process. Various attempts have been made to con-
struct roofs or upper parts to furnaces of fire clay, but which have never been
generally adopted, owing to the difficulty and expence attending the upholding
and baking of them, and this herein-before mentioned particular method

page_text: being found to succeed, and to be compatible with cheapness, and being,
moreover, intirely an Invention of my own, I am desirous of maintaining
this my exclusive right and privilege.
In witness whereof, I, the said William Harry, have hereunto set my
hand and seal, this Twentieth day of November, in the year of our
Lord One thousand eight hundred and seventeen.