IMPROVEMENTS IN SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES, AND IN MACHINERY EMPLOYED THEREIN
Year: 1854

page_text: ETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street, in
the City of London, Patent Agent, for the Invention of "IMPROVEMENTS
IN SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES, AND IN
MACHINERY EMPLOYED THEREIN."-A communication.
ealed the 20th June 1854, and dated the 19th April 1854. .
PROVISIONAL SPECIFICATION left by the said Richard Archibald
Brooman at the Office of the Commissioners of Patents, with his
Petition, on the 19th April 1854.
..I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
IMPROVEMENTS. IN SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES, AND
IN MACHINERY EMPLOYED THEREIN," (communicated to me by a foreigner residing
abroad.).
This Invention relates to the separation of substances of different specific
gravities, but more especially to the separation of metals from sand and earths,
when such metals are found in alluvial deposits. The chief purpose for which
the Invention is designed is for a gold separator to be employed as a substitute
for pan or other washers, and without the aid of water.
In obtaining the gold found in, and near streams of water, it is well known
that much labor is involved in the operation by reason of the large supply of
water requisite. The process is also known to accomplish the operation
very imperfectly, as but a portion of the gold is secured, while in times of

page_text: drought the work must be suspended or water sought for and brought to the
washings at great expence. The principle employed in this Invention is to
cause the sand, gravel, earth, and gold to become stratified, and the various
matters of which the soil may be composed to become arranged in the order
of their specific gravities by the action of air. Thus, on charging the machine
with a quantity of the auriferous sand, and working for a few minutes, it will
be found to have assumed the character just named; the gold will have settled
down to the bottom, and will be the basis of the lowest stratum, the weightiest
stones or heaviest sand will be found next, and the lightest of all the matter on
top. The manner in which this is accomplished will now be more fully shewn
by the following description:-The Drawing represents an elevation, partly
in section, of a machine constructed according to the Invention. A is a box,
having within it a bellows, pump, or other contrivance for producing a blast of
air. This is to be worked by a handle projecting through the end, or by any
other suitable contrivance. The blast is led to a chamber b, which terminates
beneath a hole in the top of the box. Over this hole there is a cylinder B,
divided into three sections B, c, d, the sections c, d, being small and lying close
to the bottom. The top has a close cover with a valve opening inwards, by
which the charge is admitted. The cylinder has also an opening e at the side,
to allow the air of one blast to escape before another is received, and it may
be covered simply by wire gauze on the inside to prevent any of the sand from
passing out. Where the sections join, the faces are made to abut one on the
other by a fine ground edge, so as to make a close fit. i is the bottom of
the cylinder, which is a strong plate punched full of holes of, say, half inch
diameter, and spaced about one inch apart; upon this is a fine wire gauze
screen o. p, q, r, are ways on which the cylinder or any of its sections may
"slide, for the purpose of affording means of emptying it of its charge. s is a hole
through the top of the box, communicating with a spout, as shown. The mode
of operating with the machine is as follows:-Let the cylinder be filled about
half full of the gold sands, then work the bellows so as to throw in a series of
-blasts of air in quick succession; this will be found to throw up and disturb
the sand, and at every lift the heaviest particles of matter will descend first,
the lightest being forced up while the other remains down or is constantly
working down; by this means the gold gradually works down, and will all be
found lying on the wire screen. When this has been accomplished the sand
may be discharged, and this is done by drawing out the bolts from the bottom,
and pushing the cylinder with its two sections c, d, along the ways p, q, r, over.
the hole s, the gauze o, and perforated plate i, being fast to the box; this
cuts off the sand as closely to the surface of the wire gauze as possible,

page_text: without taking with it any gold; the dirt having been discharged into the
spout below s, the gold may be taken off from the wire gauze, and washed
from the remaining sand and pebbles.
In continuous working, however, it is not proposed to take off the lower
5 sections each time of discharging, but to continue the operation, allowing the
gold to accumulate, at first discharging by cutting off with B, c, leaving d as
a reservoir to collect a larger amount of gold; this may be continued with
other sections, leaving an additional one as the deposit increases.
This Invention is not confined to the separating of gold merely, but is
O applicable to all other metals found mixed with sand or alluvial deposits.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 19th October 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of April, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Richard Archibald Brooman, Her special licence that I, the said Richard
Archibald Brooman, my executors, administrators, and assigns, or such others
as I, the said Richard Archibald Brooman, 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 SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES, AND
IN MACHINERY EMPLOYED THEREIN," (communicated to me by a foreigner residing
abroad), upon the condition (amongst others) that I, the said Richard Archi-
bald Brooman, by an instrument in writing under my hand and seal, 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 Richard Archibald Brooman, do
hereby declare the nature of the said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say :-
This Invention relates to the separation of substances of different-specific
gravities generally, but more particularly to the separation of metals from sand
and earths, when such metals are found in alluvial deposits. The chief purpose
for which the Invention is designed is for a gold separator to be employed as
a substitute for pan or other washers, and without the aid of water.
In obtaining the gold found in and near streams of water, it is well known
that much labour is involved in the operation by reason of the large supply of
water requisite. The process is also known to accomplish the operation very
imperfectly, as but a portion of the gold is secured, while in times of drought
the work must be suspended, or water sought for and brought to the washings
at great expense. The principle employed in this Invention is to cause the
sand, gravel, earth, and gold to become stratified, and the various matters of
which the soil may be composed to become arranged in the "order of their
specific gravities by the action of air. Thus, on charging the machine with a
quantity of the auriferous sand, and working for a few minutes, it will be
found to have assumed the character just named; the gold will have settled
down to the bottom, and will be the basis of the lowest stratum, the weightiest
stones or heaviest sand will be found next, and the lightest of all the matter
on the top. The manner in which this is accomplished will now be more fully
shewn by the following description :-
The Drawing annexed represents an elevation, partly in section, of a machine
constructed according to the Invention. A is a box, having within it a bellows,
pump, or other contrivance for producing a blast of air. This is to be worked
by a handle projecting through the end or by any other suitable contrivance.
The blast is led to a chamber 6, which terminates beneath a hole in the top of
the box. Over this hole there is a cylinder B, divided into three sections.
B, c, d, the sections c, d, being small and lying close to the bottom. The top
has a close cover with a valve opening inwards, by-which-the-charge is admitted.
The cylinder has also an opening e at the side, to allow the air of one blast to
escape before another is received, and it may be covered simply by wire gauze
on the inside to prevent any of the sand from passing out. Where the sections
join, the faces are made to abut one on the other by a fine ground edge, so as to
make a close fit. i is the bottom of the cylinder, which is a strong plate
punched full of holes of, say, half inch diameter, and spaced about one inch
apart; upon this is a fine wire gauze screen o. p, q, r, are ways on which the
cylinder or any of its sections may slide, for the purpose of affording means of

page_text: emptying it of its charge. s is a hole through the top of the box, communi-
cating with a spout, as shewn. The mode of operating with the machine is as
follows: Let the cylinder be filled about half full of the gold sands, then
work the bellows so as to throw in a series of blasts of air in quick succession.
This will be found to throw up and disturb the sand, and at every lift the heaviest
particles of matter will descend first, the lightest being forced up while the
other remains down or is constantly working down; by this means the gold
gradually works down, and will all be found lying on the wire screen. When
this has been accomplished the sand may be discharged, and this is done by
drawing out the bolts from the bottom, and pushing the cylinder with its two
sections c, d, along the ways. p, q, r, over the hole s, the gauze o, and perforated
plate i, being fast to the box. This cuts off the sand as closely to the surface
of the wire gauze as possible, without taking with it any gold; the dirt having
been discharged into the spout below s, the gold may be taken off from the
wire gauze, and washed from the remaining sand and pebbles. In continuous
working, however, it is not proposed to take off the lower sections each time
of discharging, but to continue the operation, allowing the gold to accumulate,
at first discharging by cutting off with B, c, leaving d as a reservoir to collect
a larger amount of gold. This may be continued with other sections, leaving
an additional one as the deposit increases.
This Invention is not confined to the separating of gold merely, but is
applicable to all other metals found mixed with sand or alluvial deposits.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that what I claim is,―
Effecting the separation of gold or other metals from sand or like matters,
by causing currents of air to act on the mass in such way as to cause the
particles of which it may be composed to arrange themselves in the order of
their specific gravities, and thus to collect the metal at the bottom of said
mass, as described.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Tenth day of October, One thousand
eight hundred and fifty-four.