AN IMPROVEMENT IN THE MODES OF PRODUCING AN ARTIFICIAL STONE
Year: 1824

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
ASPDIN, of Leeds, in the County of York, Bricklayer, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-first day of October, in the fifth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Joseph Aspdin, His especial licence, that I, the said Joseph Aspdin, my exors,
admors, and assigns, or such others as I, the said Joseph Aspdin, my exors,
admors, and assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "AN IMPROVEMENT
IN THE MODES OF PRODUCING AN ARTIFICIAL STONE;" in which said Letters Patent
there is contained a proviso obliging me, the said Joseph Aspdin, by an instru-
ment in writing under my hand and seal, particularly to describe and ascer-
tain the nature of my said Invention, and in what manner the same is to be
performed, and to cause the same to be inrolled in His Majesty's High Court
of Chancery within two calendar months next and immediately after the date
of the said in part recited Letters Patent (as in and by the same), reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Aspdin, do hereby declare the nature of my said Invention, and the
manner in which the same is to be performed, are particularly described and
ascertained in the following description thereof (that is to say):-

page_text: My method of making a cement or artificial stone for stuccoing buildings,
waterworks, cisterns, or any other purpose to which it may be applicable (and
which I call Portland cement) is as follows:-I take a specific quantity of
limestone, such as that generally used for making or repairing roads, and I
take it from the roads after it is reduced to a puddle or powder; but if I
cannot procure a sufficient quantity of the above from the roads, I obtain the
limestone itself, and I cause the puddle or powder, or the limestone, as the case
may be, to be calcined. I then take a specific quantity of argillacious earth
or clay, and mix them with water to a state approaching impalpability, either
by manuel labour or machinery. After this proceeding I put the above mix-
ture into a slip pan for evaporation, either by the heat of the sun or by
submitting it to the action of fire or steam conveyed in flues or pipes under
or near the pan till the water is entirely evaporated. Then I break the said
mixture into suitable lumps, and calcine them in a furnace similar to a lime
kiln till the carbonic acid is entirely expelled. The mixture so calcined is to
be ground, beat, or rolled to a fine powder, and is then in a fit state for
making cement or artificial stone. This powder is to be mixed with a suffi-
cient quantity of water to bring it into the consistency of mortar, and thus
applied to the purposes wanted.
In witness whereof, I, the said Joseph Aspdin, have hereunto set my
hand and seal, this Fifteenth day of December, in the year of our
Lord One thousand eight hundred and twenty-four.
DUNNING, Extra.
JOSEPH (L.S.) ASPDIN.
AND BE IT REMEMBERED, that on the Fifteenth day of December, in
the
year of our Lord 1824, the aforesaid Joseph Aspdin came before our said a
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Eighteenth day of December, in the year of our Lord One 3
thousand eight hundred and twenty-four.