IMPROVEMENTS IN CEMENT
Year: 1875

page_text: LETTERS PATENT to John Carrington Sellars, of Birkenhead, in the
County of Chester, Manufacturing Chemist, for the Invention of
“IMPROVEMENTS IN CEMENT."
Sealed the 8th June 1875, and dated the 12th January 1875.
PROVISIONAL SPECIFICATION left by the said John Carrington
Sellars at the Office of the Commissioners of Patents, with his
Petition, on the 12th January 1875.
I, JOHN OARRINGTON SELLARS, of Birkenhead, in the County of
Chester, Manufacturing Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN CEMENT," to be as follows:-
The kind or class of cement to which my improvements have reference.
is that now largely used for repairing, coating, setting and lining gas
retorts and other vessels, and structures subjected to heat and well.
known as Sellars' plastic cement. For the purpose of producing cement
of the said class of effective quality at a cheap rate I mix silicious sand
or stone reduced to a fine state of division with silicate of soda or potash,

page_text: Two parts of dry sand mixed with one part, by weight, of a saturated
solution of silicate of soda or potash answers well.
Under a second part of my Invention I produce cement by mixing
silicious sand, sulphate of baryta, and a soluble solution of silicate of
soda or potash. One part sand, one part sulphate of baryta, and one 5
part of a saturated solution of silicate of soda or potash thoroughly
incorporated give an excellent quality.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Carrington Sellars in the Great Seal Patent
Office on the 12th July 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CARRINGTON SELLARS, of Birkenhead, in the County of Chester, Manu-
facturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of January, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Carrington Sellars, Her
special licence that I, the said John Carrington Sellars, my executors,
administrators, and assigns, or such others as I, the said John:
Carrington Sellars, 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, exerciso, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN CEMENT," upon the condition (amongst
others) that I, the said John Carrington Sellars, my exccutors 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,

page_text: NOW KNOW YE, that I, the said John Carrington Sellars, 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 kind or class of cement to which my improvements have reference
is that now largely used for repairing, coating, setting and lining gas
retorts and other vessels, and structures subjected to heat and well
known as Sellars' plastic cement. For the purpose of producing cement
of the said class of effective quality at a cheap rate I mix silicious sand
or stone reduced to a fine state of division with silicate of soda or potash.
Two parts of dry sand mixed with one part, by weight, of a saturated
solution of silicate of soda or potash answers well.
Under a second part of my Invention I produce cement by mixing
silicious sand, sulphate of baryta, and a soluble solution of soda or potash.
One part sand, one part sulphate of baryta, and one part of a saturated
solution of silicate of soda or potash thoroughly incorporated, which gives
an excellent quality.
In carrying the first part of my Invention into practice when it is
desired to manufacture a cement which will remain plastic for a length
of time, say months, I avoid using sand or stone containing more than
one-half per cent., by weight, of lime or any of the alkaline carths, iron,
or alumina or sand, or stone containing chloride of sodium, but when it
is desired to produce a quick setting cement, lime, or any of the alkaline
earths or alumina (say fire-clay), may be used in varying proportions up
to thirty and even fifty per cent., by weight, of the silicious matter. By
a saturated solution of silicate of soda or potash I mean a solution
ranging up to 1,500° Twaddell. In reducing the sand or stone I prefer
to use horizontal French burr stones, and to mix the products with the
silicate of soda or potash under edge runners or equivalent mechanism.
The same care must be used in selecting silicious matter in carrying the
second part of my Invention into practice as is indicated above for the
first part. The same means and appliances are used as is above set
forth for the first part.
Having now described the nature of my said Invention and par-

page_text: I claim, the several improvements in the manufacture of cement herein
set forth.
In witness whereof, I, the said John Carrington Sellars, have
hereunto set my hand and seal, the Tenth day of July, in the
year of our Lord One thousand eight hundred and seventy-
five.
J. T. KING,
Witness.
JNO. C. SELLARS. (L.S.)