Parker's "Roman Cement" Patent

James Parker patented what he later called "Roman Cement" in 1796 (Patent No 2120: granted 28 June, enrolled 27 July). The text follows:

Specification for Cement for Building Purposes.

A.D. 1796 No. 2120

TO ALL TO WHOM THESE PRESENTS SHALL COME, JAMES PARKER, of Northfleet, in the County of Kent, Gentleman, sends greeting.

WHEREAS the King's most Excellent Majesty, by His Letters Patent under the Great Seal of Great Britain, bearing date the Twenty-eighth day of June, in the thirty-sixth year of His reign, gave and granted unto me, the said James Parker, my executors, administrators, and assigns, His special licence, full power, sole privilege and authority, that I, the said James Parker, my executors, administrators, and assigns, and every of them, by myself and themselves, or by my or their deputy or deputies, servants, or such others as I, my executors, administrators, or assigns, should at any time agree with, and no others, from time to time and at all times thereafter during the term of fourteen years therein expressed, should and lawfully might make, use, exercise, and vend my new Invention within that part of Great Britain called England, Wales, and Town of Berwick-upon-Tweed, of “A CERTAIN CEMENT OR TERRAS TO BE USED IN AQUATIC AND OTHER BUILDINGS AND STUCCO WORK”, in such manner as I, my executors, administrators, or assigns, should seem meet; and in which said Letters Patent is contained a proviso, that if I, the said James Parker, should 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 inrolled in His Majesty's High Court of Chancery within one calendar month 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, should utterly cease, determine, and become void, anything therein contained to the contrary thereof in any wise notwithstanding.

NOW KNOW YE, that I, the said James Parker, in pursuance of and compliance with the said proviso in the said recited Letters Patent contained, do, by this present instrument, declare that the principle and nature of my said Invention, and the manner in which the same is to be performed, is described and ascertained as follows (that is to say):—

The principle and nature of the said Invention consists in reducing to powder certain stones or argillaceous productions, called noddles of clay, and using that powder with water, so as to form a morter (sic) or cement stronger and harder than any morter or cement now prepared by artificial means. I do not know of any precise generical term for these noddles of clay; but I mean by them, certain stones of clay, or concretions of clay, containing veins of calcareous matter, having frequently, but not always, water in the center, the cavity of which is covered with small chrystals of the above calcareous matter, and the noddles agreeing very nearly in colour with the colour of the bed of clay in or near which they are found. These noddles, on being burnt with a heat stronger than that used for burning lime, generally assume a brown appearance, and are a little softened, and when so burnt and softened become warm (but do not slack) by having water thrown upon them and being reduced to powder after burning, and being mixed with water just sufficient to make into a paste, become indurated in water in the space of an hour, or thereabouts. Any argillaceous stone, then, corresponding with this description, whether known by the name of noddles of clay, or any other name, is the sort and kind only that I mean to appropriate to my own use in the fermentation of my cement.

The manner in which I prepare and compose this cement is as follows (viz.):

The stones of clay or noddles of clay are first broken into small fragments, then burnt in a kiln or furnace (as lime is commonly burnt) with a heat nearly sufficient to vitrify them, then reduced to a powder by any mechanical or other operation, and the powder so obtained is the basis of the cement.

To compose the cement in the best and most advantageous manner, I take two measures of water and five measures of the powder thus described ; then I add the powder to the water, or the water to the powder, taking care to stir and beat them during the whole time of intermixture; the cement is then made, and will set or will become indurated in ten or twenty minutes after the operation has ceased, either in or out of water.

But although I have described what I consider as the best proportions for the composition of the cement, it is expressly to be understood that these and all other proportions are to be included within the meaning and purpose of this Specification, but that no other proportion will produce so strong a cement in so short a time as those I have here pointed out; and, also, that I occasionally burn, and grind, and mix the powder before described with lime and other stones, clay, sand, or calcined earths, in such proportions as may be necessary and useful for the purpose that the cement is intended to be applied to, always observing, the less water is used the better, and the sooner the mortar or cement is used after being made, the stronger and the more durable it will be.

In witness whereof, I, the said James Parker, have hereunto set my hand and seal, this Twenty-seventh day of July, in the year of our Lord One thousand seven hundred and ninety-six.


Signed, sealed, and delivered by the within-named James Parker, in the presence of
JNo DYNELEY, of Gray's Inn.
THOs LOGGEN, Basinghall Street.

Inrolled the same Twenty-seventh day of July, in the year above written.