IMPROVEMENTS IN THE CONSTRUCTION OF MACHINES
Year: 1872

page_text: LETTERS PATENT to Joseph Theodore Dann, of 43, Cowley Road,
North Brixton, in the County of Surrey, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF MACHINES FOR
Sealed the 21st February 1873, and dated the 28th August 1872.
PROVISIONAL SPECIFICATION left by the said Joseph Theodore Dann
at the Office of the Commissioners of Patents, with his Petition,
on the 28th August 1872.
I, JOSEPH THEODORE DANN, of 43, Cowley Road, North Brixton, in
the County of Surrey, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF MACHINES
FOR WASHING, CONCENTRATING, AND AMALGAMATING ORES OF PRECIOUS METALS,"
being a communication to me from abroad by William Rickard, of
Monitor, County of Alpine, California, in the United States of America,
Assayer, to be as follows:-
Instead of employing any of the mechanical processes at present in use
for extracting precious métals from their ores I provide a vessel, tank, or

page_text: drum of iron plate or any other suitable material, made by preference of
cylindrical shape, and furnished with a longitudinal aperture fitted with
a door or valve of appropriate shape and size. Within this tank or
drum I place a longitudinal metal bar or shaft, upon one end of which
outside the tank or casing I so fit a pulley, crank, or other mechanical
contrivance as to be able to cause the bar or shaft to revolve when
actuated either by hand or by any other appropriate prime mover, such
as water,.steam, or animal power. Within the tank or drum I fit upon
the bar or shaft a series of discs or fans, formed by preference of circular
iron plate amalgamated with mercury, and alternately of V shape and
X shape; and I so prefer to vary the position of each pair of discs or
fans as always to have the apex of one V diametrically opposed to that
of the following V. Within the tank or drum I place the ores as well as
the water required for washing, concentrating, and amalgamating the
same, and upon imparting a revolving motion to the bar or shaft by the
mechanical means herein-before described the discs will receive a back
and forth or sweeping motion, whereby the water will be alternately
drawn towards a central line between the discs and thrown outward from
the same central line, and thus a dashing" back and forth of the
water in the tank will be produced. The fans or discs being amalgamated
with mercury, and revolved in the manner set forth, in water containing
fine particles of floating precious metal, known as float gold or float
silver, which in the ordinary washing processes is carried away and lost,
these particles will be caught up by the amalgamated surfaces upon
being dashed against them.
66
By a modification of my process I make the discs or fans alternately
of copper and galvanized iron, and upon actuating the same in the
manner described I produce an electrical action by which the particles
of precious metal are attracted towards and retained upon the surfaces
of the fans or discs.
By another application of the apparatus constructed according to my
Invention I use or employ the same for washing tailings in the manner
herein before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Theodore Dann in the Great Seal Patent
Office on the 27th February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
THEODORE DANN, of 43, Cowley Road, North Brixton, in the County of
Surrey, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of August in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Joseph Theodore Dann, Her special
licence that I, the said Joseph Theodore Dann, my executors, adminis-
trators, and assigns, or such others as I, the said Joseph Theodore
Dann, 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, 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 CONSTRUCTION OF MACHINES FOR WASHING, CONCENTRATING,
AND AMALGAMATING ORES OF PRECIOUS METALS," a communication to me from
abroad by William Rickard, of Monitor, County of Alpine, California,
in the United States of America, Assayer, upon the condition (amongst
others) that I, the said Joseph Theodore Dann, 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 Joseph Theodore Dann, 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, and accompanying Sheet of Drawings:-
Instead of employing any of the mechanical processes at present in
use for extracting precious metals from their ores I provide a vessel,
tank, or drum of iron plate or any other suitable material, made by

page_text: preference of cylindrical shape, and furnished with a longitudinal
aperture fitted with a door or valve of appropriate shape and size.
Within this tank or drum I place a longitudinal metal bar or shaft, upon
one end of which outside the tank or casing I so fit a pulley, crank, or
other mechanical contrivance as to be able to cause the bar or shaft to
revolve when actuated either by hand or by any other appropriate prime
mover, such as water, steam, or animal power. Within the tank or drum
I fit upon the bar or shaft a series of discs or fans, formed by preference
of circular iron plate amalgamated with mercury, and alternately of
V shape and X shape, and I so prefer to vary the position of each pair of
discs or fans as always to have the apex of one V diametrically opposed
to that of the following V. Within the tank or drum I place the ores
as well as the water required for washing, concentrating, and amalga-
mating the same, and upon imparting a revolving motion to the bar or
shaft by the mechanical means herein-before described the discs will
receive a back and forth or sweeping motion whereby the water will be
alternately drawn towards a central line between the discs and thrown
outward from the same central line, and thus a "dashing " back and
forth of the water in the tank will be produced. The fans or discs being
amalgamated with mercury, and revolved in the manner set forth in
water containing fine particles of floating precious metal, known as float
gold or float silver, which in the ordinary washing processes is carried
away and lost, these particles will be caught up by the amalgamated
surfaces upon being dashed against them.
By a modification of my process I make the discs or fans alternately
of copper and galvanized iron, and upon actuating the same in the
manner described I produce an electrical action by which the particles
of precious metal are attracted towards and retained upon the surfaces of
the fans or discs.
By another application of the apparatus constructed according to my
Invention I use or employ the same for washing tailings, in the manner
herein-before described. In this case I so agitate the water in the tank
as to permit the sulphides and other heavy materials to settle at the
bottom, whilst a continuous current of water carries off the light earthy
matter through a plug hole that may be placed in any convenient
position to enable the water to flow off freely.
By another application of my Invention I construct the apparatus
upon the same principles as herein-before described, but of such a reduced

page_text: size as to enable the same to be employed as a churn for converting
milk or cream into butter, in which case the mode of working the
apparatus is identically the same as stated in the foregoing.
In using the apparatus constructed according to my Invention as a
"concentrator"
"
or settler" I prefer to fit to the bottom thereof a
semicircular or V shaped groove, running from end to end of the tank
or drum, and I connect with this groove a kind of syphon, formed of a
smaller vessel of circular or any other appropriate shape, communicating
with the groove by means of a bent pipe, and placed and fitted so as to
have the bottom thereof on a level with the bottom of the groove, thereby
permitting the mercury to settle therein without touching it.
"
In the accompanying Sheet of Drawings I have shown in Figures 1
and 2 a cross section and a portion of a longitudinal section of such an
apparatus, constructed according to my Invention, as I prefer to use as a
" concentrator ог "settler." In the apparatus shewn in these two views
the vessel or tank is made of cylindrical or drum shape. In some cases
however it may be convenient to enlarge the size or capacity of the tank,
and to this effect the lower portion thereof may be made cylindrical, and
the upper straight or prismatic, as shewn in cross section in Figure 3.
In all these Figures the same letters of reference denote identical parts
or organs of the apparatus.
b
A is the vessel or tank, which may be made either entirely of iron or
other metal plate, as shewn in Figures 1 and 2, or the sides of which.
may be made wholly or partly of wood, as it is indicated in a fractional
view in Figure 3. At the top of the drum A I provide an aperture A¹
for charging the ores, and which may be fitted with a valve, a door, or
any other suitable appliance. B is the shaft, which I prefer to make of
iron in an apparatus of smaller dimensions, and which may be made of
wood if the circumstances of the case seem to require it, either for the
sake of economy or to render the construction lighter. The fast and.
loose pulleys O, C, are shewn in side view in Figure 2. The ends of the
shaft may be supported in plummer blocks or other descriptions of
bearings of any suitable shape, which presenting no peculiar feature in
connection with my Invention have been omitted in the Drawing.
Within the drum the V shaped discs or fans D, D, and the X shaped
ones E, E, are mounted upon the shaft B and alternated both in
order and position, in the manner herein-before described. With a view

page_text: to consolidate these discs or fans and keep them in their proper positions
I provide stays or ties F, F, varying in number and size according to the
proportions of the apparatus, and connecting the whole of the discs or
fans together. G is the groove or channel at the bottom of the tank for
collecting mercury and separating it from tailings, sulphides, or other
less heavy bodies that may be simultaneously deposited. This groove is
shewn of V shape in Figure 2, and of semicircular shape in Figure 3;
but may have any other convenient section. H is the syphon, com-
municating with the groove or channel G by means of the tube I.
In Figure 3 two varieties of sides of the upper part of the vessel are
shewn, namely, J, of iron or other suitable metal, and K, of wood.
The vessel or tank may be consolidated by means of stays L, as shewn
in Figure 3, or in any other suitable manner.
Having now described the nature of my said Invention, and illustrated
the same in the accompanying Sheet of Drawings, I wish it to be under-
stood that what I claim is,―
First. The construction of the tank or vessel with its shaft in com-
bination with a number of discs mounted thereon, substantially for the
purposes herein set forth, and in the manner illustrated in the accom-
panying Sheet of Drawings.
Second. The mode or manner, herein described, and illustrated in the
annexed Sheet of Drawings, of arranging and alternating V and X shaped
discs for the purpose of producing a fish-tail or back and forth motion in
the water.
Third. The arrangement of a groove or channel in combination with a
syphon for the purposes and in the manner herein set forth and illus-
'trated in the annexed Sheet of Drawings.
In witness whereof, I, Joseph Theodore Dann, have hereunto set
my hand and seal, this Twenty-seventh day of February, One
thousand eight hundred and seventy-two.
(L.s.) JOSEPH THEODORE DANN.