AN IMPROVEMENT IN THE MANUFACTURE OF CEMENT."
Year: 1859

page_text: LETTERS PATENT to Henry Young Darracott Scott, of Brompton Barracks,
Chatham, in the County of Kent, Captain in the Royal Engineers, for
the Invention of "AN IMPROVEMENT IN THE MANUFACTURE OF CEMENT."
PROVISIONAL SPECIFICATION left by the said Henry Young Darracott
Scott at the Office of the Commissioners of Patents, with his Petition,
on the 17th February 1859.
I, HENRY YOUNG DARRACOTT SCOTT, of Brompton Barracks, Chatham, in
the County of Kent, Captain in the Royal Engineers, do hereby declare the
nature of the said Invention for "AN IMPROVEMENT IN THE MANUFACTURE OF
CEMENT," to be as follows:-
to
My Invention of an improvement in the manufacture of cement relates
an improvement upon the Inventions for which I obtained Letters Patent,
bearing date the 17th day of April 1856, and the 19th day of February 1857,
and consists in combining with such cements as those described in the
respective Specifications of the above Letters Patent pulverized chalk, which
must be intimately mixed with the other ingredients. The object of this
addition of pulverized chalk is to give a fine and smooth face to the cement
5 when used, and to cause it to work more easily than heretofore. I sometimes
use dry slaked lime for a like purpose, either alone or as an addition to the
chalk, but the chalk is preferable on account of its cheapness.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Young Darracott Scott in the Great Seal Patent
Office on the 17th August 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
YOUNG DARRACOTT SCOTT, of Brompton Barracks, Chatham, in the County of
Kent, Captain in the Royal Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of February, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Young Darracott Scott, Her special license that I, the said
Henry Young Darracott Scott, my executors, administrators, and assigns, or
such others as. I, the said Henry Young Darracott Scott, my executors,
administrators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "AN IMPROVEMENT IN THE MANUFACTURE OF CEMENT," upon
the condition (amongst others) that I, the said Henry Young Darracott Scott,
by an instrument in writing under, my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Young Darracott Scott, do
hereby declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say):
:-
The object of this Invention is to render more suitable for plastering
purposes the cement known in the market as Scott's patent cement, and
which is prepared by the processes described under Patents obtained by me,
and bearing date respectively the Seventeentli .day of. April One thousand
eight hundred and fifty-six, and the Nineteenth day of February One thou-
sand eight hundred and fifty-seven.
In carrying out my Invention, I take the above-named cement (which is
lime that has been subjected to the process described in the Specifications of
the Patents above referred to), and if it is still in lump, which I prefer, I
grind it down in an ordinary cement mill with an equal quantity by measure

page_text: of chalk which has been previously perfectly dried; or I may vary the pro-
portion of chalk, using less or more of that material, if thought desirable.
The chalk used should be soft in its nature, and is most conveniently brought
to the degree of dryness necessary to allow it to run through the grinding mill
and through a sieve attached thereto, by exposing it to a draught of hot air, or
by placing it on a heated flue, as is practised in the manufacture of Portland
cement, with the semi-fluid paste of clay and chalk used in the preparation of
that material. This mixture will be found, though much cheaper in most
localities in England than the cement alone, to have acquired many valuable
properties for plastering purposes not possessed by the latter substance; that
is to say, it will hold better to the wall or lathwork as the workman applics
it, and will work better under the trowel when the work is required to possess
a very smooth surface. In localities where chalk cannot be had at a cheap
rate, I obtain an effect similar in kind but to a less perfect degree by using in
lieu of chalk ordinary lime slaked to a fine dry powder. In this case the
cement is first ground to a powder, and then an equal or other suitable
proportion by measure of lime is thoroughly mixed by the aid of. any convenient
mechanical means. Thus, for example, a revolving drum, mounted on an
axle furnished with arms, and turning in a contrary direction to that of the
drum by the action of suitable gearing, may be used with advantage, but other
kinds of mixing machinery may be employed; or hand labor may be used, if
thought desirable, to effect the required object. Similar methods of mixing
the chalk and cement together may be employed, each ingredient being first
reduced to a fine powder, but this mode of operating is more expensive than
grinding the two together, as above described.
Having now set forth the nature of my Invention of "An Improvement
in the Manufacture of Cement," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim increasing the adhesive and plastic qualities of the
cement known as Scott's patent cement by treating it in the manner above
described.
In witness whereof, I, the said Henry Young Darracott Scott, have here-
unto set my hand and seal, the Fifteenth day of August, in the year of
our Lord One thousand eight hundred and fifty-nine.
HENRY Y. D. SCOTT. (L.S.)