IMPROVEMENTS IN FILTERS
Year: 1854

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by Francois Mathieu at the Office of
the Commissioners of Patents, with his Petition, on the 18th August
1854.
I, FRANCOIS MATHIEU, of Bartlett's Buildings, Holhorn, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FILTERS" to be as follows:-
This Invention relates to the arrangement and construction of effective
filters of a peculiarly simple and cheap kind, so low indeed in first cost as
scarcely to exceed that of a mere vessel of reception, whilst the application of
the entire apparatus and the poriodical cleansing of the actual filtering
surfaces are accomplished with great ease. The positive filtering medium is
made up of diaphragms of felt, or other material of a like kind, with interposed
layers of charcoal or carbonaceous matter.
When intended for filtering by ascension, depositing the apparatus in a
primary receiving reservoir or cistern, the filter takes the form of a necked
vase or bottle. This chamber, which may conveniently be a plain cylinder
with a flat base, and contracted at its upper end into a discharge neck, may be
made of pewter, block tin, gutta percha, or other durable material, so as not
to be liable to fracture; but if a fragile nature is not a material objection, it
may be of porcelain or earthenware. The bottom portion of this chamber
is perforated, to admit the water or liquid to be filtered, and this perforated

page_text: diaphragm is covered over with a diaphragm or divisional piece of felt. This
felt diaphragm is cupped or turned up all round its periphery, so as to bear
well and closely against the interior surface of the chamber, a good bearing
and holding down pressure being secured by the interposition of a metal ring,
so as to distend the cupped edge; hence, such a felt diaphragm forms a
species of shallow saucer, and its recess is filled up with a layer of charcoal.
This forms the complete compound filtering diaphragm, which is repeated to
any required extent towards the top of the chamber.
The neck at the top of the chamber has attached to it a flexible or other
tube to conduct the filtered liquid away for use. This filter simply requires
placing upright on the bottom of the unfiltered water reservoir, when the
impure water therein will find access to the bottom of the chamber, and thence
ascend through all tho layers of filtering material, passing off by the neck at
the top through the flexible tube, which may be easily arranged to act as a
siphon discharger. By another modification the filter may be disposed inside
a separate stone or other chamber, and contrived so as to filter into such
chamber, the whole being placed inside the cistern, the outlet from which is in
communication with the filter holder.
A pendant filter of a simple and cheap kind may be made on this principle,
by suspending a plain filtering cylinder from any over-head support, admitting
the crude water at the open top, and drawing off the pure liquid at the bottom;
or a pedestal or vase filter may be made to filter downwards also in a similar
manner. A species of duplex cup filter may also be made, by using a
perforated external chamber with a felt covering, and enclosing a stratum of
charcoal, which again envelopes a second perforated vessel with a felt cover,
this latter vessel opening directly into a discharge pipe. This filter when
placed in a cistern filters upwards, in the manner herein-before described in
reference to my primary modification.