IMPROVEMENTS IN THE MANUFACTURE OF CEMENTS
Year: 1869

page_text: LETTERS PATENT to John Thomlinson, of No. 5, Abbey Street, Carlisle,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CEMENTS."
Sealed the 3rd May 1870, and dated the 22nd November 1869.
PROVISIONAL SPECIFICATION left by the said John Thomlinson at
the Office of the Commissioners of Patents, with his Petition, on
the 22nd November 1869.
I, JOHN THOMLINSON, of No. 5, Abbey Street, Carlisle, do hereby
5 declare the nature of the said Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF CEMENTS," to be as follows:-
This Invention has for its object improvements in the manufacture of
cements. For this purpose I burn gypsum at a red heat (that is to say
at a heat much higher than is suitable for the manufacture of plaster
of Paris), and I then grind it and mix it in dry powder with alum, tartaric

page_text: acid, cream of tartar, borax, pearlash, potash, or other alkali or acid,
the proportion of acid or alkali I propose to use being about one-twentieth
part of the weight of the gypsum. The cement is then ready for use
and no burning is required subsequent to mixing; this arises from the
burning of the crude gypsum having been effected at a high heat, as
above stated, which is new in the manufacture of cement. Sand, ashes,
broken bricks, or burnt clay may be mixed with the cement when it
is used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Thomlinson in the Great Seal Patent Office
on the 21st May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, L, JOHN
THOMLINSON, of No. 5, Abbey Street, Carlisle, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of November, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Thomlinson, Her special licence that
I, the said John Thomlinson, my executors, administrators, and assigns,
or such others as I, the said John Thomlinson, my executors, adminis-
trators, 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 "IMPROVEMENTS IN THE MANUFACTURE
OF CEMENTS," upon the condition (amongst others) that I, the said John
Thomlinson, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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 John Thomlinson, do hereby declare
the nature of the said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object improvements in the manufacture
of cements. For this purpose I burn gypsum at a red heat (that is to
say at a heat much higher than is suitable for the manufacture of
plaster of Paris), and I then grind it and mix it in dry powder with
alum, tartaric acid, cream of tartar, borax, pearlash, or potash. The
proportion I propose to use being about one-twentieth part by weight of
either of these substances to one part of the gypsum, these proportions
may however be to some extent varied. The cement is then ready for
use and no burning is required subsequent to mixing; this arises from
the burning of the crude gypsum having been effected at a high heat,
as above stated, which is new in the manufacture of cement. Sand, ashes,
broken bricks, or burnt clay may be mixed with the cement when it
is used.
What I claim is, the manufacture of cement substantially as herein.
described.
In witness whereof, I, the said John Thomlinson, have hereunto
set my hand and seal, this Twentieth day of May, in the year of
our Lord One thousand eight hundred and seventy.