IMPROVEMENTS IN THE MANUFACTURE OF BRICKS OR BUILDING BLOCKS."
Year: 1868

page_text: LETTERS PATENT to Holmes Cheney Crofts, of Chatham, in the
County of Kent, Chemist, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF BRICKS OR BUILDING BLOCKS."
PROVISIONAL SPECIFICATION left by the said Holmes Cheney Crofts
at the Office of the Commissioners of Patents, with his Petition, on
the 15th May 1868.
I, HOLMES CHENEY CROFTS, of Chatham, in the County of Kent,.
Chemist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF BRICKS OR BUILDING BLOCKS," to be
as follows:-
The bricks or building blocks which form the subject of this my
Invention are made in the following manner :-I take three parts by
weight of Portland cement and one part by weight of grey stone lime.
The lime is slaked with a solution of sulphate of iron. The strength of
the solution will vary the colour from very light yellow to dark brown..
The solution which I prefer to use contains one pound to the gallon
and gives an agrecable fawn colour. This mixture being made tolerably.

page_text: stiff is laid on the sides of the mould, being placed thicker in the
bottom of the mould which forms the face of the brick. On the sides
of the mould it is placed about a quarter of an inch in thickness and
upon the face of the brick from one half to one inch in thickness;
this may vary however according to the size of the block. The inside
of the mould is then filled with concrete formed by grey stone lime
and gravel, broken stones, or other hard and suitable material. When
so made they dry of themselves in a short time sufficient to be turned
out of the mould. The further drying is obtained by placing the
blocks in stacks in the open air or under cover.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Holmes Cheney Crofts in the Great Seal Patent
Office on the 6th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HOLMES
CHENEY CROFTS, of Chatham, in the County of Kent, Chomist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of May, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Holmes Cheney Crofts, Her special licenco
that I, the said Holmes Cheney Crofts, my executors, administrators,
and assigns, or such others as I, the said Holmes Cheney Crofts,
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 thercin 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 BRICKS OR BUILDING BLOCKS," upon
.the condition (amongst others) that I, the said Holmes Cheney Crofts,
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

page_text: 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 Holmes Cheney Crofts, 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 :-
For building houses and all other erections for which ordinary bricks
are available to be as follows, and to consist of two separate or distinct
parts, the first part forming the face or outside portion of the brick or
block, and the second part the internal or filling-in portion of the
same.
For the external facing I take three parts by weight of Portland
cement and one part also by weight of greystone, blue lias, or other
lime having similar qualitics to these, and having slaked the lime with
a solution of sulphate of iron (the strength of which solution will vary
the color of the product from pale yellow to dark brown) of the strength
of one pound sulphate to one gallon of water, which produces an
agrecable fawn color. I then add the cement, and with a sufficiency
of the solution of iron work them well together either by hand labor
or machinery until of a proper consistence for plastering, which I then
spread over the bottom of my mould to the thickness of from half to
onc inch, which forms the face of the brick or block. I also extend
the facing material about a fourth of the distance up the sides of the
mould, gradually sloping it off to a thin edge, and in the corners to
the top or somewhat higher than the mould, leaving a small portion
to turn back on the opposite side of the brick or block when
finished.
.
For the body or filling-in material of the aforesaid block or brick I take
a mixture of broken flint, granite, small gravel, broken bricks or tiles,
hard chalk or chalk stone, or other hard and rough material not mixed in
any definite proportion and mix with this compound about a fourth volume
of small cinders or cinder ash. Of this mixture I take three or four
measures and one measure of greystone or other similar lime (the
proportion varying both here and in the facing material according to
the strength or quality of the lime used), and half a measure of builders'
sand, and of Portland or Roman cement a fourth part by weight of
the lime used. Having slaked the lime I then mix it with the sand and
add sufficient hot or cold water (giving preference to the former) to

page_text: bring it to about the consistence of cream; I then stir in the cement,
and add lastly the mixture of broken stones, &c., with more water as
required to bring it to a proper consistence, and when thoroughly
incorporated either by hand labor or in a suitable mill or machine I
proceed to fill in the mould (which I construct with moveable or hinged
sides for the more convenient liberation of the block when finished)
whilst the facing composition is still wet and soft, pressing the filling-in
material gently down with a tamping stick so as to blend it with the
facing where the two come into contact. When the blocks are removed
from the moulds, which will be in from four to six hours, they are
gradually dried in the open air, and will be fit for use in from two to
four weeks according to the size of the block and state of atmosphere at
the time prevailing.
The advantages claimed under this Invention as compared with
ordinary bricks are greater durability of substance, increased elegance
of appearance, and saving in cost, blocks of this description being
produceable at about half the price of ordinary bricks of approximate
finish and hardness. Owing to the last quality possessed by this
material blocks of considerable size might be constructed hollow and
still possess as great power of resistance as a corresponding bulk of
brick and mortar, thus still further reducing cost in erecting works of
magnitude.
In witness whereof, I, the said Holmes Cheney Crofts, have here-
unto set my band and seal, this Sixth day of November,
in the year of our Lord One thousand eight hundred and sixty-
eight.
HOLMES CHENEY CROFTS. (L.S.)