CONSIDERABLE IMPROVEMENTS IN THE PROCESS OF MANUFACTURING AN ARTICLE COMMONLY CALLED IVORY BLACK, AND FOR PULVERIZING, GRINDING, OR REDUCING TO A SUBTLE AND FINE POWDER ALL ARTICLES CAPABLE OF A MORE EASY SEPARATION OF THEIR PARTS OR CONSTITUENT PRINCIPLES BY TORREFACTION, HEATING, OR CALCI- NATION, IN OPEN OR CLOSE KILNS, OVENS, OR FURNACES, ESPECIALLY POTTERS' CLAY, FLINTS, COLOURING AND GLAZING MATERIALS
Year: 1810

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME I, WILLIAM
DOCKSEY, of the City and County of Bristol, Millwright, do send greeting.
WHEREAS His most Excellent Majesty George the Third, by His Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Twenty-second day of May now
last past, did give and grant unto me, the said William Docksey, my executors,
administrators, and assigns, His especial licence, full power, sole privilege and
authority, that I, the said William Docksey, my executors, administrators,
and assigns, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of
"CONSIDERABLE IMPROVEMENTS IN THE PROCESS OF MANUFACTURING AN ARTICLE
COMMONLY CALLED IVORY BLACK, AND FOR PULVERIZING, GRINDING, OR REDUCING TO
A SUBTLE AND FINE POWDER ALL ARTICLES CAPABLE OF A MORE EASY SEPARATION
OF THEIR PARTS OR CONSTITUENT PRINCIPLES BY TORREFACTION, HEATING, OR CALCI-
NATION, IN OPEN OR CLOSE KILNS, OVENS, OR FURNACES, ESPECIALLY POTTERS' CLAY,
FLINTS, COLOURING AND GLAZING MATERIALS;" in which said Letters Patent there
is contained a proviso, obliging me, the said William Docksey, under my hand
and seal, to cause a particular description of the nature of my said Invention,
and in what manner the same is to be performed, to be inrolled in His
Majesty's High Court of Chancery within two calendar months next and
immediately after the date of the said in part recited Letters Patent, as in and
by the same, relation being thereunto had, may more fully and 'at large appear,
otherwise the said Letters utterly to cease, determine, and become void.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Docksey, do hereby declare that my said Invention is fully described
and ascertained in manner following (that is to say):-
:-
My Invention consists in manufacturing ivory black, and all articles capable
of an easy separation of their parts or constituent principles, by torrefaction,
heating, or calcination, such as potters' clays, flints, colouring and glazing
materials, with a very small quantity of water in grinding or reducing the
said articles to fine powder; by which means or process much machinery and
labour employed in the processes now used in manufacturing the said articles
with a large portion of water are avoided in the stoves employed to heat the
rooms or other places for evaporating the water used in the processes now
practised rendered unnecessary, and which processes of drying ivory black
greatly hurt and impair its colour. In order that my several improvements
may be clearly understood I shall proceed to detail my processes more particu-
larly, premising that I do not mean to confine myself to the exact machinery
and processes here described, in which divers variations may be made, as my
Invention depends on grinding or reducing the several articles above mentioned
to a subtle powder by omitting to use any considerable quantities of water.
First. To manufacture ivory black, I take the bones and sloughs of the horns
of animals and calcine them to blackness in close or air-tight vessels; I then
crush them in their dry state between metal rollers, of about two feet diameter,
until they are broken sufficiently small to pass through a hopper into the eye
of a millstone, and be reduced to powder between millstones in an horizontal
situation, exactly similar to the method of reducing or grinding corn or grain
to flour by a like process. The powder thus obtained is then partly passed
through a dressing machine, constructed with brushes and fine iron or brass
wire upon a circular frame, inclosed within a bin, which receives it; such part
as passes thro' the meshes of the wire (which should be about sixty-eight to an
inch) is sufficiently fine for use, and is damped down by a small quantity of
water sprinkled upon it, and packed for sale; the coarser part is returned to
the hopper and ground over again between the stones.
Secondly. In respect to flints, potters' clays, and colouring and glazing mate-
rials, my method is to take calcined flints, dried clays, calcined lead and lead
ores, and manganese, or whatever article is proper for glazing, and pass it under
stampers or heavy hammers to break or bruise it into small pieces sufficiently
small to pass between metal rollers, where it is crushed so fine as to be reduced
to a pulverulent state; it is then ground in its dry state between millstones, in
a manner similar to that before described for manufacturing ivory black; it is
then passed through a dressing machine (inclosed within a very tight and close

page_text: bin, which receives it). The coarser parts being thus separated the finer part
is then mixed with water in a tub or deep vessel; the coarser parts are farther
separated by subsidence, and the finer and thinner parts passed through a fine
lawn or Cyprus sieve; the water is then drained off and evaporated by hea
from the substance, and the powder thus obtained is of a superior kind of
fineness.
In witness whereof, I, the said William Docksey, have hereunto set my
hand and seal, this Seventeenth day of July, in the year of our Lord
One thousand eight hundred and ten.
Inrolled the Twenty-first day of July, One thousand eight hundred
and ten.