IMPROVEMENTS IN APPARATUS FOR WASHING AND AMALGAMATING ORES AND OTHER MATTERS."
Year: 1856

page_text: LETTERS PATENT to John Mitchell, of Dunnings Alley, Bishopsgate
Street Without, for the Invention of "IMPROVEMENTS IN APPARATUS
FOR WASHING AND AMALGAMATING ORES AND OTHER MATTERS."
PROVISIONAL SPECIFICATION left by the said John Mitchell at the
Office of the Commissioners of Patents, with his Petition, on the 17th
.March 1856.
.I, JOHN MITCHELL, of Dunnings Alley, Bishopsgate Street Without, do
hereby declare the nature of the Invention for "IMPROVEMENTS IN APPARATUS
POR WASHING AND AMALGAMATING ORES AND OTHER MATTERS," to be as
follows:
This: Invention consists of apparatus which cause the pulverized ores and
matters which are to be washed or amalgamated to be moved together with
the fluid in troughs by screws. For this purpose two troughs are formed side
by side, parallel to each other. These troughs are divided by a partition of
such a height, that the current of fluid and matters under process may
pass from trough to trough. In the two troughs are two screws revolving in
opposite directions; or they are otherwise. so made that the fluid and, matters
under process in one trough may be moved in an opposite direction to the fluid
and matters under process in the other trough.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Mitchell in the Great Seal Patent Office on the
12th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MITCHELL, of Dunnings Alley, Bishopsgate Street Without, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of March, in the year of our
Lord One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Mitchell, Her special licence that I, the said John Mitchell,
my executors, administrators, and assigns, or such others as I, the said John
Mitchell, my executors, administrators, and assigns, should at any time agreo
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 APPARATUS
FOR WASHING AND AMALGAMATING ORES AND OTHER MATTERS," 'upon the con-
dition (amongst others) that I, the said John Mitchell, 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 Mitchell, do hereby declaro the
naturo of the said Invention, and' in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention consists of apparatus which cause the pulverized ores and
matters which are to be washed or amalgamated to be moved together with
the fluid in troughs by screws. For this purpose two troughs are formed side
by side, parallel to each other; these troughs are divided by a partition of
such a height that the current of fluid and matters under process may
pass from trough to trough. In the two troughs are two screws revolving in
opposite directions; or they are otherwise so made that the fluid and matters
under process in one trough may be moved in an opposite direction to the fluid
and matters under process in the other trough.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the samo.

page_text: DESCRIPTION OF THE DRAWING.
Figure 1 shows an end elevation, Figure 2 a plan, and Figure 8 an
elevation in transverso section, of a machine combined according to my
Invention.
a, a, is a vessel of such a form that two semicircular divisions or troughs exist
at the lower part; 6, 6, are two screws, carried by two axles c, c, and put in
motion by the cog wheels d, d; e, e, are pullies for carrying a strap to give motion
to the whole, One pulley is fixed to the axle and the other loose, a combination
known to engineers as fast and loose pulleys. f, g, h, are three openings, placed
one above the other, and are used as exits for allowing the partially or wholly
dressed, washed, or amalgamated materials to pass off, each opening being used
according to the nature of the materials operated on; i, i, are two stop cocks,
for the purpose of emptying the troughs of their contents when required.
In case the orcs or other matters are only to be washed or dressed no
mercury is put into the troughs; but if the process of amalgamation has to be
carried on in conjunction with the washing and dressing operations, then
mercury must be placed in each of the troughs. The operation is thus per-
formed:-The materials to be operated upon are reduced to such a state
of division as may be considered necessary, and when the two screws are put
in motion, by means of the oog wheels and pullies, are allowed to run into the
machine with water, the quantity of which varies according to the nature of
the substances operated on; if amalgamation is to be performed mercury must
be placed in each of the troughs. By the motion of the screw, the materials which
are to be amalgamated or washed or dressed are gradually moved from one
end of one trough to the other end of the same, and are then also by the action
of the screw forced over into the other trough, where a similar operation
is repeated; this motion being slow, allows the heavier portions of the materials
to pass over and in contact with the surface of the mercury contained in the
troughs, which said materials are also, by the action of the inclined blades of
the screws, carried through the body of the mercury without breaking up the
bulk of the same, whilst the lighter portions of the said materials are by the
excess of water carried off through some one of the openings f, g, h. When it
is thought that a sufficient quantity of the heavier matters have been collected,
they are removed through the taps or stop cocks i, i. In case the materials are
to be amalgamated, mercury is placed in each of the troughs. I prefer to
employ a series of such washing and amalgamating machines; the refuse
matters passing from the first into a second placed at a little lower level, and
so on with another, or as many as may be considered necessary.

page_text: Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not claim any of
the parts separately, nor do I confine myself to the details; but what I claim
is the combination of machinery herein described for washing and amalgamating
ores and other substances.
In witness whereof, I, the said John Mitchell, have hereunto set my hand
and seal, this Eleventh day of September, in the year of our Lord One
thousand eight hundred and fifty-six.
Witness,
A..CARPMAEL.
JOHN MITCHELL. (L.B.)