IMPROVEMENTS IN FIRE-BRICKS AND OTHER ARTICLES INTENDED TO RESIST THE ACTION OF FIRE, THE SAID IMPROVEMENTS INCLUDING COMPOSITIONS PROVISIONAL SPECIFICATION
Year: 1873

page_text: LETTERS PATENT to William Henry Tooth, of Sewardstone Road, in
the County of Middlesex, Engineer and Chemist, and William
Henry Tooth, the younger, of the same Place, for the Invention
of "IMPROVEMENTS IN FIRE-BRICKS AND OTHER ARTICLES INTENDED TO
RESIST THE ACTION OF FIRE, THE SAID IMPROVEMENTS INCLUDING COMPOSITIONS
PROVISIONAL SPECIFICATION left by the said William Henry Tooth
and William Henry Tooth, the younger, at the Office of the Com-
missioners of Patents, with their Petition, on the 18th April 1873.
We, WILLIAM HENRY TOOTH, of Sewardstone Road, in the County
of Middlesex, Engineer and Chemist, and WILLIAM HENRY TOOTH, the
younger, of the same Place, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FIRE-BRICKS AND OTHER ARTICLES INTENDED
TO RESIST THE ACTION OF FIRE, THE SAID IMPROVEMENTS INCLUDING COMPOSITIONS
TO BE USED IN THE MANUFACTURE OF THE SAME," to be as follows:-
By careful investigation we have discovered great differences in the
various qualities of the materials of which fire-bricks, gas house retorts,
fire-lumps, and other articles (intended to resist the action of fire) are
made and the reason why they vary so much in their properties for
resisting the action of heat and atmospheric influences, and for the
purpose of correcting the defects commonly found in fire-brick and

page_text: other fire-resisting materials, and preventing the variations in quality,
and making fire-brick and other articles of the exact qualities required,
as near as may be) out of the various materials now in use, and others
which abound in the kingdom, we make or cause to be made for the
purpose of resisting the action of fire certain chemical compounds of
alumina, silicate of alumina, and oxide of silica (whether containing
oxide of iron or not), in such proportions as will form compounds from
80 to 90 per cent. of oxide of silica, and from 20 to 10 per cent. of
alumina, that is to say, to 80 per cent. of oxide of silica there should
be 20 per cent. of alumina; to 81 of silica there should be an
admixture so as to produce 19 per cent. of alumina; to 82 per cent. of
silica there should be 18 per cent. of alumina; to 83 per cent. of silica
there should be 1.7 per cent. of alumina and so on in proportion up to
90 per cent. of silica and 10 per cent. of alumina. These proportions
will resist the action of an intense heat, and we number these
compounds from No. 1 to No. 10.
The mode of operation for producing these compounds is as follows:-
First. We take a quantity of potters' clay or fire-clay, or other
materials containing silica of alumina, or alumina, and ascertain by
analysis the quantity of alumina and silica contained therein, and for
composition No. 1, take such a quantity as contains 20 per cent. in
pounds, hundredweights, or tons of alumina, and calculate the amount
of silica contained therein (in pounds, hundredweights, or tons); and if
there should be 24 per cent. in pounds, hundredweights, or tons of silica
to the 20 per cent. of alumina, take of clean washed sand (or oxide of
silica) 56 per cent. in pounds, hundredweights, or tons, taking care it has
been thoroughly washed and cleansed from all impurities of earthy
matter, and add that to the silicate of alumina, thus forming a compound
of 80 per cent. of silica to 20 per cent. of alumina. We thoroughly mix
them together either by hand, pug mill, or other mixing machine, and
set the mixture aside for a few days, when it will be fit for use and can
be moulded into any articles required, and by subjecting such articles to
the action of a strong heat the particles will enter into chemical
combination with each other and form a strong fire-resisting brick and
other articles.

page_text: alumina, and grind it to powder, and mix it with the before-mentioned
proportion of oxide of silica in a dry state for convenience of sifting.
Third. In such cases where the spaces between the firework are to
be thoroughly closed together by the heat applied, we take the before-
mentioned proportions of silicate of alumina and thoroughly dry it,
adding thereto 20 per cent. of cinder, ashes, coke, breese, or other
carbonaceous matter, and grind them to powder, and then mix them
with the before-mentioned quantity of oxide of silica to make up the
80 per cent.
If thought desirable silicate of magnesia or other equivalent silicate
material may be used. These proportions can be varied to such an
extent as will cause the compound to partly or wholly vitrify where
various temperatures are required, so as to cement the bricks together.
In manufacturing ordinary bricks and other articles there will be no
necessity to follow the precautions of washing and cleansing the
materials as before-mentioned, and the proportions can also be varied as
may be required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Henry Tooth and William Henry Tooth,
the younger, in the Great Seal Patent Office on the 18th October
1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
HENRY TOOTH, of Sewardstone Road, in the County of Middlesex,
Engineer and Chemist, and WILLIAM HENRY TOOTH, the younger, of the
same Place, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of April, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Henry Tooth and William
Henry Tooth, the younger, Her special licence that we, the said William-
Henry Tooth and William Henry Tooth, the younger, our executors,
administrators, and assigns, or such others as we, the said William Henry
Tooth and William Henry Tooth, the younger, our executors, adminis-

page_text: "
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 FIRE-BRICKS
AND OTHER ARTICLES INTENDED TO RESIST THE ACTION OF FIRE, THE SAID Improve-
MENTS INCLUDING COMPOSITIONS TO BE USED IN THE MANUFACTURE OF THE SAME,'
upon the condition (amongst others) that we, the said William Henry
Tooth and William Henry Tooth, the younger, our executors or adminis-
trators, by an instrument in writing under our, 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 we, the said William Henry Tooth and William
Henry Tooth, the younger, do hereby declare the nature of our said
Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following state-
ment :-
Our improvements consist in mixing together certain portions of
silica or oxide of silicon with certain proportions of alumina which can
be ascertained by analysis of the ingredients to be used, and to make this
Specification plain, we will first observe that in the generality of fire-clay
beds the proportions of silica and alumina vary to a considerable extent,
so that the bricks made from one portion of a clay bed will vary
considerably in quality from those made from another portion of clay
taken from the same bed, and the object we have in view and have
discovered and put into practice by our Invention is to correct such
inequalities and enable the manufacturers to make bricks and other
articles of uniform quality to suit the purposes for which they are
required, as various qualities are required for various purposes; and to
accomplish this object we make an analysis of the clay to be used and
ascertain the quantity of alumina or oxide of aluminium which it
contains, and also the quantity of oxide of silicon.
:
Now to make No. 1 material for making bricks or other articles
whether from fire-clay or potters' clay, or gault, we take a bulk of the
clay, say fifty or one hundred tons, more or less, crush it or grind it to

page_text: powder and thoroughly mix it in a heap, we then take from any part of
this heap a sample and ascertain by analysis the quantity of alumina
and silica contained therein; and should it prove to contain less than;
twenty per cent. of alumina to eighty per cent. of silica, then we add a
5 sufficient quantity of potters' clay or other aluminous material to bring
it up to the standard or equivalents required, and vice versa. If on the
contrary the sample taken should prove to contain more than twenty
per cent. of alumina, then silica must be added to reduce the proportion
to that amount. Number 2 and all qualities must be prepared in the
same way, but in accordance with the different proportions hereafter
mentioned.
Number 2, being eighty-one per cent. of silica to nineteen per cent. of
alumina.
Number 3, being eighty-two per cent. of silica to eighteen per cent. of
Ď alumina.
Number 4, being eighty-three per cent. of silica to seventeen per cent.
of alumina.
Number 5, being eighty-four per cent. of silica to sixteen per cent. of
alumina.
Number 6, being eighty-five per cent. of silica to fifteen per cent. of
alumina.
Number 7, being eighty-six per cent. of silica to fourteen per cent. of
alumina.
Number 8, being eighty-seven per cent. of silica to thirteen per cent. of
alumina.
Number 9, being eighty-eight per cent. of silica to twelve per cent. of.
alumina.
Number 10, being eighty-nine per cent. of silica to eleven per cent. of
alumina.
Number 11, being ninety per cent. of silica to ten per cent. of
alumina.
Should it be found desirable to make the articles required very
compact in their texture very find sand must be used; and after it has
been washed and freed from all impurities, it should be calcined before
being mixed with the alumina, and if potters' clay be preferred it should
be washed and the heavier particles of silica allowed to subside, and this
we do for the manufacture of gas house retorts, where a compact body is
J
:

page_text: required to prevent the gas escaping through their pores. Where fine
silicious sand cannot be procured then calcined flints ground to powder
can be used.
In preparing our fire-clay for laying the bricks we vary the proportions
considerably, so as to produce a fusible compound at the various
temperatures to which different furnaces are subject, for instance a
furnace heated to one thousand degrees of heat requires a much easier
fusible compound than a furnace heated to three thousand degrees, and
for this purpose we make for a low temperature a composition of twenty-
five per cent. of alumina and fifty per cent. of silica, with twenty per
cent. of burnt mineral carbon and five per cent. of lime, and so
proceed for higher temperatures' to reduce the quantity of alumina and
lime, and increase the quantity of silica, still keeping the quantity of
carbonaceous matter about the same, and by attention to these
instructions an article to answer any degree of fusibility can be obtained.
The desirability of these improvements will be apparent from the fact
that as the bricks are now laid with wet fire-clay, the clay in becoming
dry contracts and leaves open spaces through which cold air passes into
the furnaces, doing serious injury in many operations.
Lastly. It will be seen for different purposes different qualities of fire-
bricks are required, and it is one of the characteristics of this patent
process that all these various qualities can be made by simply varying
the quantities of the ingredients used, which at the present time is not
done by any other process or manufacture. This power of versatility of
compound of the same materials, though so very simple when under-
stood, enables us to make fire-bricks suitable for the various purposes for
which fire-bricks are required; thus these bricks are made to supply lime
kilns, cement kilns, puddling furnaces, balling furnaces, or re-heating
furnaces, glass houses for plate, crown, or sheet, or large flint glass
houses, gas works, iron foundries, brass foundries, boiler furnaces, and
blast furnaces, and all descriptions of chemical works, which is of great
importance, as the acid or alkalies produced at a very great heat rapidly
destroy the present fire-bricks used, and it must be borne in mind that
the construction of these compounds is considerably less than that of
ordinary fire-clay or potters' clay according to the mixture heretofore
used, and therefore the moulds for bricks must be made to allow only
half an inch for shrinkage in length, a quarter of an inch in width, and
three-sixthteenths in thickness, and allowance should also be made for
:

page_text: all other articles manufactured in the proportion that these materials
only contract in drying about one half of that of ordinary fire-bricks.
To the above general rules there are certain exceptions; for instance,
bricks required for lime burning require a larger amount of alumina than
is herein-before stated, and also those for certain chemical operations will
require various proportions of alumina and silica ranging from seventy
per cent. of silica to thirty per cent. of alumina; but such compositions
as the last-named are not intended to resist the action of heat only, but
they are intended to resist the chemical action of materials being manu-
factured which must be allowed for according to chemical laws.
"
Having now particularly described and ascertained the nature and
object of our Invention, and in what manner the same is to be performed
or put in practice, we hereby declare that we claim the Invention of
Improvements in Fire-bricks and other Articles intended to Resist the
Action of Fire, the said Improvements including Compositions to be
used in the Manufacture of the same," but in conclusion we may remark
that although we have stated the various proportions required, in order
under various circumstances to carry out our Invention, yet some slight
variations might be adopted in some peculiar cases according as the
practical man may determine; but the general scope of the directions
above stated must always be adopted, we therefore claim the Invention
in manner above set forth.
In witness whereof, we, the said William Henry Tooth and William
Henry Tooth, the younger, have hercunto set our hands and
seals, this Fifteenth day of October, in the year of our Lord Onc
thousand eight hundred and seventy-three.
Witness,
30
T. MORGAN,
Secretary,
WILLIAM H. TOOTH.
(L.8.)
WILLIAM HY. TOOTH, JUN³. (L.S.)
Inventors' Patent Right Association, Limited,
21, Cockspur Street,
S. W.