IMPROVEMENTS D FILTERS
Year: 1859

page_text: LETTERS PATENT to John Roberts, of Upnor, in the County of Kent,
Terra Cotta Manufacturer, for the Invention of "IMPROVEMENTS D
FILTERS."
Sealed the 20th December 1859, and dated the 25th June 1859.
PROVISIONAL SPECIFICATION left by the said John Roberts at the
Office of the Commissioners of Patents, with his Petition, on the
25th June 1859.
I; JOHN ROBERTS, of Upnor, in the County of Kent, Terra Cotta Manu-
facturer, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN FILTERS," to be as follows:-
The object of this Invention is to provide a cheap and efficient filter par-
ticularly applicable for filtering water, as the temperature of the fluid subjected
to its action may at the time of filtration be greatly reduced.
In carrying out this double object I form a vessel of any suitable shape of
porous earthenware open at the top, but with a loose cover to close it and
keep out dust. This vessel, which I term the cooler, I pierce with holes above
the level of the filtered water that I desire to retain in the vessel, to allow
of the free circulation of air therein, and I suspend in the cooler a smaller
vessel of a cylindrical or other convenient shape of still more porous earthen-
ware, which I term the filter. To the bottom of the cooler I fit a tap for
drawing off the filtered water, and the water to be filtered I supply either by
hand or by a self-feeding apparatus to the filter; when the simple operation of
filtering without cooling is required I form a porous vessel of a conical or
This
funnel shape, but with a closed end, and with fluted or ribbed sides.
vessel I propose to use in conjunction with an ordinary jug or other convenient
or suitable vessel, dropping it into the mouth thereof, whereby it is held in

page_text: suspension.
Water or other liquid being then poured into the filter it will
quickly percolate through in a pure and limpid state.
For making the filtering vessel I prefer to use potters ordinary clay com-
bined with powdered charcoal and ground flint, and a substance obtained from
the Staffordshire mines partaking somewhat of the nature of loam, but not
heretofore employed in pottery manufacture.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Roberts in the Great Seal Patent Office on the 24th
December 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ROBERTS, of Upnor, in the County of Kent, Terra Cotta Manufacturer, send
greeting.
'
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of June, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Roberts, Her special license that I, the said John Roberts,-
my executors, administrators, and assigns, or such others as I, the said John
Roberts, 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
FILTERS," upon the condition (amongst others) that I, the said John Roberts,
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.
IN
NOW KNOW YE, that I, the said John Roberts, do hereby declare
the nature of my 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, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say): -
The object of this Invention is to provide a cheap and efficient filter par-
ticularly applicable for filtering water, as the temperature of the fluid subjected
to its action may in hot weather be greatly reduced during filtration,

page_text: In carrying out this double object I form a vessel of any suitable shape of
porous earthenware open at the top, but with a loose cover to close it and
keep out dust. This vessel I pierce with holes above the level at which
I desire to retain the filtered water in the vessel, in order to allow of the
free circulation of air therein. In the cooler I suspend a smaller vessel of a
cylindrical or other convenient shape made of still more porous earthenware,
which vessel receives the water to be filtered, and allows it to percolate
through the sides and bottom thereof. The outer vessel or cooler I fit with a
tap for drawing off the water as it is required for use.
In the accompanying Drawings Fig. 1 shews the improved filter in front
elevation, and Fig. 2 is a vertical section of the same. It consists of an
outer vessel a, a, formed of porous earthenware, such as that used in the
manufacture of butter coolers and wine coolers, and moulded with a shoulder
and lip at its upper end, and an inner vessel b, formed of honeycomb earthen-
ware, and by preference cylindrical, and furnished with a flange or lip which
rests upon the shoulder of the vessel a, the whole being closed by a cover c.
Through the upper part of the vessel a, rings of fine holes d, d, are pierced
for the admission of air to the interior, and at its lower end a tap e is fitted
for drawing off the filtered water. For convenience, I find it desirable to
make the lip or flange of the filtering vessel b, with ordinary clay to give it
strength (as indicated by color in the detached view, Fig. 3), the porous com-
position being somewhat tender, and requiring therefore care when being
handled. Carelessness therefore in replacing the filtering vessel (after re-
moving it from the vessel a for the purpose of cleansing it), and letting it fall
into its place with a jerk would probably without this provision cause the
frequent fracture of the fitting vessel. The honeycomb sides and bottom I
form by using the following mixture of materials, viz., Kentish clay, three
parts; ground flint, one part; vegetable or animal charcoal, two parts; and
Staffordshire loam, one part. These substances when mixed or pugged
together are moulded into the required shape, and while still in the green or
unbaked state, the lip of ordinary clay is applied thereto. When fired a
perfect junction will be formed between the two parts. The action of this
improved filter is as follows:-Water being poured into the vessel b, it will find
its way through the honeycomb sides and bottom, and trickle down into the
vessel a. Free access of air being allowed to this vessel by means of the rings
of holes d, the water will become aerated in its descent, and thus the insipidity
or flatness peculiar to filtered water will be removed. By making the vessel a of
porous earthenware the outer surface will remain moist, and if the atmospheric
temperature be high, evaporation will take place sufficient to reduce the tem-

page_text: perature within the vessel several degrees. When the simple operation of
filtering with or without aerating, but without cooling the water is required
I use a glazed outer vessel which requires less frequent cleansing, and to
facilitate the cleaning of the filtering medium I propose to give that a slight
glazing, but so as to leave the pores or honeycomb openings free. Although
I have indicated that the filter is to be filled by hand, yet when required a
self-feeding apparatus may be applied to the filter. As a simple and inexpen-
sive filter for the labouring classes, and suitable also, by a slight modification
in its form, to soldiers on the march, 1 form a porous vessel of a conical or
funnel shape, but with a closed end, and with fluted or ribbed sides as shewn
in elevation at Fig. 4, and in inverted plan view at Fig. 5. This vessel I pro-
pose to use in conjunction with an ordinary water bottle, jug, or other con-
venient or suitable vessel, dropping it into the month thereof as shewn at
Fig. 6, whereby it is held in suspension. Water or other liquid being then
poured into the filter, it will quickly percolate through in a pure and limpid
state, and run down the flutes or channels in its sides into the receiver. As
these channels also form channels for the air to pass along, the filtered
water will in this case also be partially aerated, I would remark that this
filtering vessel is, for the purpose of strength, formed of ordinary clay at its
upper part, but with the honeycomb composition for the filtering surface.
This vessel like the vessel b, may, if required, be coated with a thin glaze,
but I do not recommend glaze, as unless very carefully used it will materially
retard the filtering operation.
Having now set forth the nature of my Invention of improvements in filters,
and explained the manner of carrying the same into effect, I wish it to be
understood that under the above in part recited Letters Patent I claim, the
means herein described for effecting the filtration, and the filtration and cooling
of water and other fluids.
In witness whereof, I, the said John Roberts, have hereunto set my
hand and seal, the Twenty-third day of December, in the year of our
Lord One thousand eight hundred and fifty-nine.
Witness,
RICH. S. LOWE.
JOHN ROBERTS. (L.S.)
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