GIVING TO STATUES AND OTHER ORNAMENTAL WORKS IN PLASTEB (COMMONLY CALLED PLASTER OF PARIS) AN APPEARANCE NEARLY RESEMBLING THE FINEST STATUARY MARBLE, AT THE SAME TIME RENDERING THEM MORE HARD AND DURABLE, LESS LIABLE TO BE SOILED AND EASIER TO BE CLEANED
Year: 1809

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
PENWARNE, of the Parish of Saint Pancras, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS His Majesty King George the Third, by His Letters Patent
under the Great Seal of Great Britain, bearing date at Westminster, the
Twenty-sixth day of September, in the forty-ninth year of His reign, did, for
Himself, His heirs and successors, give and grant unto me, the said John
Penwarne, my exors, admors, assigns, or such others as I, the said John
Penwarne, my exors, admors, or 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, and exercise, and sell, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention or
process for "GIVING TO STATUES AND OTHER ORNAMENTAL WORKS IN PLASTEB
(COMMONLY CALLED PLASTER OF PARIS) AN APPEARANCE NEARLY RESEMBLING THE
FINEST STATUARY MARBLE, AT THE SAME TIME RENDERING THEM MORE HARD AND
DURABLE, LESS LIABLE TO BE SOILED AND EASIER TO BE CLEANED;" in which said
Letters Patent there is a proviso, obliging me, the said John Penwarne, by an
instrument in writing under my hand and seal, particularly to describe and

page_text: ascertain the nature of my said Invention, and in what manner the same is
to be performed, 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 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 tho said proviso, I, the said
John Penwarne, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is described and
ascertained in the explanation hereof, that is to say:-
The principle of my said Invention is to impregnate the said plaster
of Paris with the sulphate of alumine, commonly called alum; in order to
effect which, I pursue the following process as being the easiest and best
adapted for carrying the said principle into practice. A solution of the sul-
phato of alumine or alum in water is prepared in a proportion of about one
pound of alum to every three pints of water (but it is not necessary to observe
these exact proportions, as a greater or less quantity of alum will answer the
intended purpose). The liquor is then made to boil, or heated to a degree
of temperature sufficient to dissolve the quantity of alum put into it. The
plaster cast, previously dried, and properly finished or cleaned off, is then
immersed in the above solution, and suffered to remain therein from fifteen
minutes to half an hour; it is then taken out and suspended over the vessel
containing the solution. After having been suffered to cool for two or three
minutes, according to the size and bulk of the figure, some of the solution is
dipped up and thrown over it, or applied to it by means of a sponge or linen
cloth, and which is continued till the alum forms a fine crystallization over its
surface of a due degree of thickness. When it is sufficiently done it is set by
to dry, and when it is perfectly so it may be brought to a due degree of smooth-
ness or polish by means of sand paper or glass paper, and finished by being
rubbed with a fine linen cloth slightly moistened with clean water. As most
vessels of metal, except those of lead or tin, are liable to impart a stain to the
liquor, I make use of wooden vats, which are conveniently heated by steam
introduced through a leaden pipe from a boiler.
In witness whereof, I, the said John Penwarne, have hereunto set my
hand and seal, the Fifteenth day of November, One thousand eight
hundred and nine.
JNO PENWARNE. (L.s.)

page_text: AND BE IT REMEMBERED, that on the Fifteenth of November, in the
year of our Lord 1809, the aforesaid John Penwarno came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
5 written. And also the Specification aforesaid was stampt according to the
tenor of the Statute made for that purpose.
Inrolled the Fifteenth day of November, in the year of our Lord One
thousand eight hundred and nino.