CERTAIN IMPROVEMENTS IN FILTRATION
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
MENCKE GEROTHWOHL, late of Camberwell Grove, in the County of Surrey,
and now of Great Winchester Street, in the City of London, Merchant, send
greeting.
WHEREAS, in consequence of a communication from a Foreigner residing
abroad, I am in possession of an Invention of "CERTAIN IMPROVEMENTS IN
FILTRATION," and whereas His present most Excellent Majesty King William
the Fourth, by His Letters Patent under the Great Seal of Great Britain,
bearing date at Westminster, the Twenty-eighth day of May, in the sixth year
of His reign, did, for Himself, His heirs and successors, give and grant unto
me, the said Joseph Mencke Gerothwohl, my exors, admors, and assigns,
His special license, that I, the said Joseph Mencke Gerothwohl, my exors,
admors, and assigns, or such others as I, the said Joseph Mencke Gerothwohl,
my exors, adñiors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of fourteen years therein
expressed, should and lawfully might make, use, exercise, and vend my said
Invention within England and Wales and the Town of Berwick-upon-Tweed; in

page_text: which said Invention is contained a proviso obliging me, the said Joseph Mencke
Gerothwohl, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, and to cause the same to be inrolled in
His Majesty's High Court, within six calendar months next and immediately
after the date of the said recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Mencke Gerothowhl, do hereby declare the nature of the said Inven-
tion to consist in more speedily filtering water by means of the pressure
of the unfiltered water remaining in the cistern or reservoir containing
the same, and introduced into the filtering machine, as herein-after men-
tioned, and by introducing into the filtering machine two distinct sets or
beds of filtering materials, and adjusting the same therein, and admitting
the unfiltered water therein in such manner that part of the unfiltered water
will pass through one of such beds, and be thereby filtered, and the other
part of such unfiltered water will at the same time pass through the other of
such beds, and also be filtered. And in further compliance with the said
proviso I, the said Joseph Mencke Gerothwohl, do hereby declare the manner
in which the said Invention is to be performed by the following Statement,
that is to say: "
I take a barrel or upright cylindrical or square or other vessel, made
of wood, or metal, or any other convenient material, with a water-tight bottom,
and I line the sides of the same with cloth. The shape of the vessel is not
essential, but I prefer à barrel or upright cylindrical or square vessel; and
it is not essential that the sides of the said vessel should-be-lined with cloth,
but 'such a lining renders the filtering machine more easily completed, and
protects the sides of the vessel against the filtering material. At a short
distance, say about two inches from the bottom of the said barrel or other
vessel, the precise distance is immaterial, but it is convenient that such
distance should not be less than the diameter of the pipe or hose admitting
he unfiltered water,-I place a horizontal board pierced with very small
holes, and fitting the said barrel or vessel, so as to form a false bottom, about
said two inches above the true water-tight bottom of the said barrel or
vessel. Upon this pierced board I place a bed of filtering materials, say
flint, sand, and grey stone, or other filtering materials, varying according to the
quality of the water, about one foot in depth. It is not essential that the
said bed of filtering materials should be about one foot in depth, but I find

page_text: rests.
that depth the most convenient in ordinary cases, and generally adopt it.
Immediately above this bed of filtering material I introduce a horizontal
pierced board, precisely similar to the board on which the said bed of filtering
material rests, and the said board is fitted in the barrel or vessel in the same
manner as the said pierced board on which the said bed of filtering material
At the same distance above the upper pierced board that the lower
pierced board is above the bottom of the vessel I place another similarly
pierced and similarly fitting horizontal board, and upon such board I place
a like bed of filtering materials, consisting of the same substances and being
of the same depth as the filtering materials firstly herein-before described,
and immediately above this bed I place another similarly pierced and similarly
fitting horizontal board. The barrel or vessel is hermetically closed with
a top about the same distance above the uppermost pierced board that the
lowest pierced board is above the bottom of the barrel or vessel. It is not
essential that the top should be this distance above such board, but such
distance is sufficient, and the distance must not be less than the diameter
of the pipe admitting the unfiltered water. I I pass a pipe from the uppermost
to the lowest pierced board, one end of such pipe being firmly fitted into tho
said upper pierced board, and such pipe passing through the said other pierced
boards and beds of filtering materials, and the other end thereof passing
through and being fitted into the lowest pierced board. This pipe I call
the pipe of communication. The filtering machine then consists of an
hermetically closed barrel or vessel, fitted with two distinct beds of filtering
materials, each of which beds is inclosed between two horizontal pierced
boards fitted in the said barrel or vessel, and the space between the top of
the vessel and the uppermost of the said pierced boards is connected with
the space between the bottom of the said barrel or vessel and the lowest of the
said pierced boards by a pipe of communication. I place the said filtering
machine lower than the said cistern or reservoir containing the unfiltered
water, and I introduce the said unfiltered water into the said filtering machine
by means of a pipe, herein-after called the unfiltered water pipe, and which
pipe is furnished with a cock, for the purpose of letting the said unfiltered
water into the said filtering machine, or shutting off the same at pleasure.
One end of the said pipe goes from and is fitted tightly into the said unfiltered
water cistern or reservoir, and the other end thereof is fitted tightly into the
said filtering machine either at the side thereof and between the top thereof
and the uppermost pierced board, or at the top thereof, but I prefer tho
said pipe to be fitted into the side thereof, and between the top thereof and the

page_text: said uppermost pierced board as aforesaid. A leathern hose may be substituted
instead of the whole or any part of the said unfiltered water pipe, but it is
essential that the communication between the unfiltered water reservoir or
cistern and the said filtering machine be water-tight, so that the unfiltered
water may have no means of escape, but must necessarily pass from the
reservoir or cistern into the said filtering machine, and be pressed by the
weight of the unfiltered water in such reservoir or cistern through one or
other of the beds of filtering material. When the unfiltered water is by the
means aforesaid introduced into the filtering machine as aforesaid, it flows
into the vacant space between the top or lid thereof and the uppermost
pierced board, and part of such unfiltered water passes through the uppermost
pierced board and upper bed of filtering material, and through the pierced board
on which such bed rests, into the space between such last-mentioned board
and the board next lower down, and the other part of such unfiltered water
passes through the pipe of communication herein-before described; and such
part so passing through such pipe of communication as aforesaid is, by the
pressure of the water in the reservoir or cistern and in the machine, forced
npwards through the lowest pierced board, and through the bed of filtering
materials resting thereon, and through the pierced board above the same into
the space between the said last-mentioned pierced board and the pierced board
whereon the upper bed of filtering materials rests, where it meets the other
part of the water which has passed through the said upper bed of filtering
materials. The water having passed through one or other of the said beds of
filtering materials is drawn off or let out by means of a pipe, herein-after called
the clean water pipe, which pipe is fitted into the side of the vessel between the
pierced board on which the upper bed of filtering material rests and the
pierced board next below the same, and which is immediately above the
lower bed of filtering material. This pipe is furnished with a cock for the
purpose of drawing off the filtered water at pleasure. The unfiltered water
pipe, instead of being fitted into the filtering machine between the top thereof
and the uppermost pierced board, or into the top thereof, as herein-before
described, may be fitted into the part of the said filtering machine herein-
before mentioned as the place for the clean water pipe. In that case the
clean water pipe must be placed or fitted where the unfiltered water pipe
was previously described to be fitted, and in that case part of the unfiltered
water will, by the pressure aforesaid, be forced through the upper bed of
filtering materials into the space between the upper pierced board and the top
or lid of the vessel, and other part of the said unfiltered water will be forced

page_text: through the lower bed of filtering materials into the space between the lowest
pierced board and the bottom of the said vessel, and thence it will be pressed
up through the pipe of communication to the space between the uppermost
pierced board and the top of the said vessel, when it will meet the part of
the water which has been pressed through the upper bed of filtering materials.
It may then be drawn off by the clean water pipe fitted into the said filtering
vessel between such uppermost board and the top thereof, or fitted into the
top thereof; or the said unfiltered water pipe may be fitted into the said
machine between the bottom thereof and the lowest pierced board, or into the
bottom thereof, when a similar process of filtration will take place, and the
filtered water will collect between the pierced board on which the upper bed
of filtering materials rest and the pierced board immediately above the lower
bed of filtering materials, and be then let off by the clean water water pipe,..
situate as firstly herein-before described; or the situation of the clean and
unfiltered water pipes in the process lastly described may be changed, and the
unfiltered water may be introduced into the filtering machine through the
pipe in the side thereof between the two centre pierced boards, and after
being filtered let off by a clean water pipe fixed into the side of the said
filtering machine between the bottom thereof and the pierced board imme-
diately above the said bottom, or by a clean water pipe fixed into the bottom
thereof. The pipe of communication, instead of passing within the said
filtering machine, may pass on the outside thereof; and the space between the
uppermost pierced board and the top of the said machine may be connected
with the space between the lowest pierced board and the bottom of the said
machine by such pipe of communication passing outside the said machine, one
end of such pipe being fitted into such machine between the uppermost pierced
board and the top thereof, or being fitted into the top thereof, and the other end
thereof being fitted into the side of the said machine between the lowest pierced
board and the bottom thereof, or being fitted into the bottom thereof. In either
case I furnish such pipe of communication, or some pipe let into the same,
with a cock for letting the filtered water out of the said pipe of communication,
or the unfiltered water from the cistern into the said pipe of communication,
as the case may be, as herein-after more particularly mentioned. And in case
the said pipe of communication passes outside the said filtering machine I
introduce and fit the unfiltered water pipe into the side of the said machine
between the pierced board on which the upper bed of filtering material rests
and the board immediately above the lower bed of filtering materials. Part of
such unfiltered water passes through the said upper bed of filtering materials;

page_text: and part thereof through the lower bed of filtering material, and such several
parts communicating by means of the herein-beforo described pipe of commu-
nication, and may be drawn off or let out by means of the pipe and cock
connected therewith, or cock therein herein-before mentioned; or the said
unfiltered water may be introduced through the said pipe and cock into the
said filtering machine, and part thereof will pass through such pipe into the
space between the uppermost pierced board and the top or lid of the said
filtering machine, and thence through the said upper bed of filtering material
to the space between the pierced board on which the said upper bed of
filtering material rests and the pierced board immediately below the same,
and the other part of such unfiltered water will pass into the space between
the bottom of the said filtering machine and the lowest pierced board, and
thence be pressed upwards through the lower bed of filtering material, when it
will meet the water which has passed through the upper bed of filtering
materials, and may be drawn off through the clean water pipe, as firstly
herein-before described (or the said unfiltered water may be introduced into
the filtering machine lastly described through the bottom thereof by a like
process of filtration, pass through the said clean water pipe, fitted as lastly
herein-before mentioned), or the said unfiltered water may be introduced into
the said filtering machine lastly described, through the bottom thereof, by tho
unfiltered water pipe passing through and being fitted into the bottom thereof,
and passing through the lowest pierced board and the lower filtering bed and
the pierced board immediately above the same, the end of the said unfiltered
water pipe being a little below the said pierced board on which the uppermost
bed of filtering material rests, and a little above tho pierced board immediately
over the lowest bed of filtering material. In that caso part of the said
unfiltered water will pass through the upper bed of filtering material into the
pipe of communication, and part thereof will pass through the lower bed of
filtering material into the said pipe of communication. Such machine, with such
pipe passing from the bottom thereof between the two middle pierced boards
thereof, I call the middle-pipe filtering machine; or the operation may be reversed,
and the unfiltered water introduced through the said pipe of communication.
In any case where the pipe of communication is used to connect the water
that has been filtered through the upper bed with the water that has been
filtered through the lower bed, instead of such pipe two cocks or separate
pipes may be introduced and fitted into the sides of the filtering machine, ono
of such pipes or cocks being fitted therein into the side of the said machino
between the top thereof and the said uppermost pierced board, or into the top

page_text: thereof, and the other of such pipes or cocks being fitted into the side thereof
and between the bottom thereof and the said lowest pierced board, or into the
bottom thereof; and in such case the filtered water will pass through and into
such separate pipes or cocks, and may be drawn off into separate: vessels;
and unfiltered water may, in like manner, be introduced through two distinct
and separate unfiltered water pipes, the one communicating with the space
between the top of the said machine and the uppermost pierced board, and the
other with the space between the bottom thereof and the lowest pierced board;
and the filtered water may, in such case, be let off or drawn off by a pipe or
cock fitted into the side of the machine between the said pierced board on which
the upper bed of filtering material rests, and the board immediately above the
lower bed of filtering material. In those cases where the unfiltered water is
by any means introduced into the filtering machine in the space between the
pierced boards on which the upper bed of filtering material rests and the
pierced board immediately above the lower bed of filtering material, it is not
essential for the purpose of filtration that the filtering machine should be.
hermetically closed, or that there should be a top thereon; but it is convenient,
as the filtered water will otherwise rise nearly to the height of the unfiltered
water in the reservoir or cistern of unfiltered water, I prefer and generally
adopt the machine and method firstly herein-before described. Either of the
filtering machines herein-before described may be washed by passing filtered
or clean water through them the reverse way; and in case the unfiltered water.
pipe be fastened in to the reservoir or cistern of unfiltered water it will be
convenient to furnish the machine with a cock near to such unfiltered water
pipe for the purpose of discharging from the machine the water used in.
washing or cleaning the same introduced through the clean water pipe, which
has been passed through the machine the reverse way to that in which the
water usually passes. Where the filtering machino is required to be of a
large size I introduce the unfiltered water through an unfiltered water pipe
fitted into the bottom of a vat or wooden or other vessel, and I cover the
opening of the said pipe with a case of wood or metal or porcelain, pierced
with very small holes. Upon the bottom of the said vessel I place a layer of
flints about six or eight inches thick, and, upon such flints a layer of sand
about four or six inches thick, and immediately above such bed of flints and
sand I place a water-tight lid or covering of board, with a hole and pipe at the
top thereof for the water to pass through such lid with the layers of flint and
sand, and the bottom and side of the said vessel form what I call a purifier.
I introduce the water which has passed through the top or lid of such purifier

page_text: into any of the filtering machines herein-before described; but the most
convenient machine, and the one I generally adopt, I formed by combining
such purifier with the filtering machine herein-before described, and called
the middle-pipe filtering machine, and so that the pipe or lid of such purifier
may form the bottom of such middle-pipe filtering machine. In such case tho
lower end of the pipe passing through from the bottom of the purifier
between the middle boards of the said middle-pipe filtering machine, is cased
over with boards, or wood, or metal, or porcelain, pierced with small holes,
and I furnish the said purifier with a small door for the purpose of easily
removing and replacing the said layer of flint and gravel therein. In any of the
machines herein-before described plates of iron, or metal, or of earthenware, or
of porcelain, fitted into the the said filtering machine, and pierced with very
small holes, may be substituted for the boards pierced with holes herein-before
described.
Now whereas I do not claim as the said Invention the use of the substances
composing the beds of filtering materials, or the use of the pierced boards, or
metal, or earthenware, or porcelain inclosing the said beds of filtering
materials, or the shape of the filtering machine; but I claim as the said
Invention the following improvements, that is to say:-
The introducing the unfiltered water into the filtering machine by a
water-tight pipe or hose communicating with and fitted into the cistern or
reservoir containing the same, so that the unfiltered water in such reservoir
or cistern acts upon and presses the water in the filtering machine, and the
unfiltered water therein having no means of escape is by such pressure
speedily forced through one or other of the beds of filtering materials in the
said filtering machine; and,
Secondly, in introducing into the said filtering machine two distinct beds of
filtering material, and adjusting the same therein, and admitting the unfiltered
water therein in such a manner that part of the unfiltered water will pass through
one of such beds and be thereby filtered, and the other part of such unfiltered
water will at the same time pass through the other of the said beds and also
be filtered. And such Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of His said Majesty's
United Kingdom of Great Britain and Ireland called England, His said
Majesty's Dominion of Wales, or the Town of Berwick-upon-Tweed, I do
hereby declare this to be my Specification of the same, and that I do verily
believe that this my Specification doth comply in all respects, fully and without
reserve or disguise, with the said proviso in the herein-before in part recited

page_text: Letters Patent contained; wherefore I do hereby claim and maintain exclusive
right and privilege to the said Invention.
In witness whereof, I, the said Joseph Mencke Gerothwohl, have here-
unto set my hand and seal, this Second day of November, in the
year of our Lord One thousand eight hundred and thirty-six.
JOSEPH M. GEROTHWOHL. (L.S.)
Signed, sealed, and delivered, by the
above-named Joseph Menke Geroth-
wohl, in the presence of
CHRISTIAN Kосп,
H. B. Maj Consul to the Free City of Frankfort,
James Hertslet, of Brompton, in the County of Middlesex, Gentleman,
Sub-librarian to His Majesty's Principal Secretary of State for Foreign
Affairs, maketh oath and saith, that he has custody of the Official Correspond-
ence of different Foreign Consuls with the said Secretary of State, and among
others of Christian Koch, His Britannic Majesty's Consul to the Free City of
Frankfort-on-the-Maine, in Germany, and that he is well acquainted with his

page_text: character and style of writing, and especially with his official signature; and
this Deponent further saith, that he has carefully inspected the two signatures
purporting to be those of the said Christian Koch, subscribed to two different
Attestations, one of them by way of Caption, at the foot of the Deed Poll or
Specification hereto annexed, and that ho has no doubt whatever that they are
the proper signatures and handwriting of the said Christian Koch.
LA U
Inrolled the Twenty-first day of November, in the year of our Lord 20
One thousand eight hundred and thirty-six.