AN IMPROVED MANUFACTURE OF CEMENT
Year: 1857

page_text: LETTERS PATENT to Henry Young Darracott Scott, of Brompton
Barracks, near Chatham, in the County of Kent, Captain in the Royal
Engineers, for the Invention of "AN IMPROVED MANUFACTURE OF
CEMENT."
Sealed the 14th August 1857, and dated the 19th February 1857.
PROVISIONAL SPECIFICATION left by the said Henry Young Darracott
Scott, at the Office of the Commissioners of Patents, with his Petition,
on the 19th February 1857.
I, HENRY YOUNG DARRACOTT SCOTT, of Brompton Barracks, near Chatham,
in the County of Kent, Captain in the Royal Engineers, do hereby declare
the nature of the said Invention for "AN IMPROVED MANUFACTURE OF CEMENT,"
to be as follows:-
This Invention relates to certain improvements in a process patented by
me, and bearing date April 17th, 1856, wherein burned lime is subjected to
the action of sulphurous acid, and thus a plaster, stucco, or mortar, which will
quickly set and attain a considerable degree of hardness is produced, the
action being apparently due to the presence of a small per-centage of sulphato
consequent upon this treatment.
I now propose to mix intimately with burned lime, before it has been
slaked by the addition of water, a small per-centage of sulphate of lime
or other sulphate, or to treat it with a small quantity of sulphuric acid.

page_text: Or, instead of mixing with the burned lime a sulphate, I propose to subject
the burned lime to the action of sulphurous acid, in order to form the sulphate
without the special application of heat to the lime, or when the lime has
cooled down after burning. Or, I may find it convenient to use instead of
sulphates, salts containing sulphurous acid, which would likewise admit of
conversion into sulphuric acid with formation of sulphates.
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 19th August-1857.
TO ALL TO WHOM THESE PRESENTS- SHALL COME, I, HENRY
YOUNG DARRACOTT SCOTT, of Brompton Barracks, near 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 Nineteenth day of February, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth 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 IMPROVED 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 par-
ticularly 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 imme-
diately 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):-

page_text: My Invention of "An Improved Manufacture of Coment" relates to
certain improvements in a process previously patented by me, and bearing
date April Seventeenth, One thousand eight hundred and fifty-six, wherein
-burned line is subjected to the action of sulphurous acid, and thus a plaster,
stucco, or mortar, which will quickly set and attain a considerable degree of
hardness is produced, the action being apparently due to the presence of a
small per centage of sulphate consequent upon this treatment. .
The object of the present Invention is to impart to quicklime the properties
of a "cement" by means of an inexpensive and convenient process, which is
carried out in the following manner: Lime, prepared by any of the
ordinary methods, is by mechanical means reduced to a powder, and is
intimately mixed with from five to ten per cent. of its weight of gypsum,
sulphate of lime, or calcined gypsum, or sulphate of lime (commonly known
as plaster of Paris), or sulphate of iron, or sulphate of magnesia, may be
added thereto.
In order to produce a sufficiently fine state of division, and intimate
admixture of the several ingredients, I find it convenient first to mix the
lime and either of the sulphates above-mentioned by hand, and then to grind
them in a mill, and finally pass them through a bolting sieve.
The lime should be perfectly fresh when used, but should have been drawn
from the kiln a day or two, according to the state of the atmosphere, before
grinding. The resulting mixture is packed in bags or casks for use, and is
treated as other calcareous cements.
I do not, however, confine myself to the exact proportions above given, nor
to the foregoing method of procuring the admixture of a sulphate, for the
same effect may be produced by the addition of hydrated sulphuric acid of
any degree of concentration. The addition of sulphuric acid is most con-
veniently effected by injecting or throwing the liquid, through a rose head of
platinum or glass, on to or amongst the particles of quicklime as they are
delivered from the millstones through a cylinder, or an equivalent result may
be produced by subjecting them under the same circumstances to the fumes
of sulphuric acid produced by heat.
Having now described my Invention of "An Improved Manufacture of
Cement," and having explained the means of carrying the same into effect, I
claim as the Invention secured to me by Letters Patent, as aforesaid, the
preparation of a cement by the intimate admixture with pulverized. unslaked
lime, made in the usual way, of a small per-centage of sulphate of lime,
calcined or uncalcined, or of sulphate of iron, or of sulphate of magnesia, or

page_text: of sulphuric acid, either of which will produce an equivalent result, whereby a
useful and inexpensive cement may be obtained.
In witness whereof, I, the said Henry Young Darracott Scott, have
hereunto set my hand and scal, the Nineteenth day of August, in the
year of our Lord, One thousand eight hundred and fifty-seven.
HENRY SCOTT. (L.S.)·