CERTAIN IMPROVEMENTS IN THE PROCESS OF CALCINING AND PREPARING CALCARIOUS AND OTHER SUBSTANCES POR THE PURPOSE OF FORMING CEMENTS
Year: 1823

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FROST, of Finchley, in the County of Middlesex, Builder, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by
His Letters Patent under the Great Seal of His United Kingdom, bearing
date at Westminster, the Third day of April 1823, in the fourth year of His
reign, give and grant unto me, the said James Frost, my exors, admors, and
assigns, His especial licence, full power, sole privilege and authority, that I,
the said James Frost, my exors, adiñors, and assigns, during the term of years
therein mentioned, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "CERTAIN IMPROVEMENTS IN THE PROCESS OF CALCINING AND PREPARING
CALCARIOUS AND OTHER SUBSTANCES POR THE PURPOSE OF FORMING CEMENTS;" in
which said Letters Patent there is contained a proviso, that if I, the said
James Frost, 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 band and seal, and 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 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) will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Frost, do hereby declare that the nature of my said Invention, and the
manner in which the same is to be performed, are particularly described and
ascertained in and by the following description thereof (that is to say):-
My process consists in calcining calcarious substances, or any natural or
artificial admixtures thereof, with other earths or oxides that are useful for
the purpose of forming cements, in such manner that they may be cooled
previous to any access of the external atmospheric air or of moisture, and this
I effect by calcining the aforesaid substances in reverberatory furnaces or kilns
with a due degree of heat, and which degree will generally depend upon the
nature of the substances acted upon, the purest calcarious substances generally
requiring most, and the most compound substances least heat, and by stopping
and luting all the apertures of the furnace and continuing them closed till the
furnace and its contents are cool; or I withdraw the hot calcined material
through an aperture in the floor of the furnace (such aperture being kept
closed during calcination), into an iron or other cylinder with a corresponding
aperture, but impevious to air or moisture on all other sides but that in
contact with the floor of the furnace, and I allow the calcined substance to
cool therein, and while another portion is being calcined in the furnace, for
such mixtures of calcarious and other earths and oxides as can be sufficiently
calcined at a bright red heat. I calcine in tight iron cylinders or retorts,
heated in proper furnaces, and furnished with safety valves to emit vapour
while heating, and to exclude the atmospheric air in cooling, and allow the
cylinders to cool previous to withdrawing the calcined mixture; or I attach
other cylinders to the ends of the before-named cylinders, to receive the
calcined materials, and defend them from the contact of external air or
moisture while cooling, and while another portion is being calcined in the
first-named cylinders. The cylinders used for cooling should have doorways
in them to allow the calcined substances to be withdrawn, they should be
fitted with doors air-tight, or rendered so by luting. The cooling cylinders
may also be partly surrounded and inclosed in other larger cylinders, and
water may be introduced into the space contained between them, which will
greatly increase the cooling power of the inner cylinder, and the heat com-
municated to the water may be applied to useful purposes. The furnaces,
kilns, and heating cylinders must have proper apertures for introducing the
substances to be calcined, and for occasionally stirring and removing them, and
either concrete or pulverized substances may be acted upon.
I declare my process consists in duly calcining calcarious substances, or

page_text: natural or artificial admixtures thereof, with other earths or oxides useful for
the purpose of forming cements in any manner, so that they may be cooled
without any external access of atmospheric air or of moisture during the cooling.
In witness whereof, I, the said James Frost, have hereunto set my hand
and seal, this Second day of October, in the year of our Lord One
thousand eight hundred and twenty-three.