Frost's "British Cement" Patent

Specification for Cement or Artificial Stone.

A.D. 1822 No. 4679

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 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 Eleventh day of June now last past, did give and grant unto me, the said James Frost, my exors, adfriors, and assigns, His special licence, full power, sole privilege and authority, that I, the said James Frost, my exors, adrnors, and assigns, during the term of years therein expressed, should and lawfully might make, use, exercise, and vend, within England and Wales, and the Town of Berwick-upon-Tweed, my Invention of “A NEW CEMENT OR ARTIFICIAL STONE”; in which said Letters Patent there is contained a proviso, obliging me, the said James Frost, under my hand and seal, to cause a particular description of the nature of my said Invention, and in what manner the same is to be performed, 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 said Letters Patent, relation being thereunto had, may more fully and at large appear.

NOW KNOW YE, that I, the said James Frost, do, by this present writing under my hand and seal, and intended to be inrolled in the said Court of Chancery, pursuant and in obedience to the condition contained in the said Letters Patent as aforesaid, certify and declare, that for the purposes of my said invention I select such limestones or marls or magnesian limestones or marls as are entirely or nearly free from any admixture of alumine or argillaceous earth, and contain from nine to forty per cent. of siliceous earth, or silica, or combinations of silica and oxide of iron, the silica being in excess and in a finely-divided state, and break such selected materials into small pieces, which are then calcined in a kiln, in the manner calcareous substances usually are, until all carbonic acid be expelled, and until it be found on trial of a small portion of such calcined materials that it will not, when cool, slack or fall when wetted with water. The calcined material is to be ground to a fine powder by any machinery fit for reducing dry substances to that state, and the powder is the material for making the cement or artificial stone, and must be kept in dry packages for use. When used it is to be mixed with water and tempered to the consistency of common mortar; it should be mixed in small quantities, and applied instantly to its intended purpose, as it will set in a few minutes to resist the impression of the finger, and gradually harden to a stony body. For many purposes a quantity of clean siliceous sand may be advantageously incorporated with it when it is tempered for use. The cement will be lighter or darker in colour as there is a lesser or greater quantity of oxide of iron in the selected materials; the lighter colour will be found best adapted to dry, and the darker colour to wet situations.

I declare that my Invention is for making a cement or artificial stone from siliceous limestones or marls in the manner herein-before described, and that I shall call it by the name of British cement.

In witness whereof, I, the said James Frost, have hereunto set my hand and seal, the Tenth day of August, in the year of our Lord One thousand eight hundred and twenty-two.

JAMES (L.S.) FROST.

Signed, sealed, and delivered by the within-named James Frost, in the presence of
W. LYTHGOE,
C. MORSE, Clerks to J. Lythgoe, of Essex Street, Strand, Sol^r.

AND BE IT REMEMBERED, that on the Tenth day of August, in the year of our Lord 1822, the aforesaid James Frost came before our said Lord the King in His Chancery, and acknowledged the Specification aforesaid, 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 Tenth day of August, in the year of our Lord One thousand eight hundred and twenty-two.