Year: 1886

page_text: I, CHARLES CARROLL GILMAN of Eldora, Iowa United States of America,
Manufacturer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:--
My invention relates to improvements in filtering.
In the accompanying drawings forming a part of this specification,
Fig. 1 is a vertical section of a filtering cistern constructed in accordance with
my invention.
Fig. 2 is a vertical central section of a well embodying my invention.
Fig. 3 is a perspective view of the block of filtering material forming the bottom
of the well.
Fig. 4 is a similar view of one of the blocks of filtering material used in building
the walls of the well.
In the construction of my improved Filters, Filtering cisterns, and wells I use as a
filtering material porous earthenware products. By the term "porous earthenware"
I mean an earthenware material which has been rendered porous by the burning
out in the kiln of vegetable matters, such as sawdust, straw, etc., for example,
previously mixed with the clay. I use this porous earthenware material in two
forms, one in which all the imprisoned vegetable matters have been burned out or
consumed in the kiln, and the other in which the firing has been carried to an
extent sufficient only to burn out the combustible materials to a certain depth
below the surface, but not sufficient to consume the sawdust or vegetable matter
located beyond this or in the interior of the mass and which portion is merely
converted by the heat into charcoal. This product as herein first defined is an
excellent filtering material by means of which a large quantity of water can be
quickly and effectually filtered. It is therefore adapted and can be used to great
advantage in the construction of wells and cisterns. This porous earthenware also
acts as an indestructible filtering support for other filtering material that may be
used in connection therewith. In the second form hereinbefore referred to it filters
more effectually than in the first form but not quite so rapidly.
For a cistern the porous product, in either form, is employed as a false bottom,
being suitably supported at a proper distance above the bottom of the cistern. In
the drawing Fig. 1, I have represented one form of cistern A in which supports C
•

page_text: of wood or brick resting on the bottom A¹ of the cistern support the false bottom D
of porous earthenware. The said false bottom is preferably about 3 inches in
thickness. It may be supported in any other effectual manner, but the form shown
is preferred. The water after passing through the porous earthenware may pass
through openings b into a reservoir that may be located near by or situated at a
distance therefrom. Cisterns of this construction may be located near a river or
lake and the water may flow or be pumped into the same, passing in a filtered
state from thence into the storage reservoir that may be provided. Several
filtering cisterns A, may be used all discharging into one and the same storage
reservoir and from such a reservoir a city or village may be supplied with pure
water.
For the purpose of rendering the process of filtering more perfect, I spread upon
the described false bottom a layer of coarse clean gravel preferably about 6 inches
thick and upon the gravel I spread an equal layer of pure sand. The water
in percolating through the false bottom alone will be reasonably well filtered but
the gravel and sand will aid in still further purifying the water.
When the porous earthenware has become unduly loaded with impurities, the
sand and gravel (if employed) may be removed and the blocks of porous earthen-
ware taken up and turned over. The water in percolating through will then force
the deposited impurities out the way they entered.
In Fig. 2 I have illustrated a well in which the walls are built of porous
earthenware, in either of its hereindescribed forms as may be desired. The water
from the surrounding earth will percolate through the walls of such a well and
pass into the interior of the same in a filtered condition. The principle of the
operation is the same as in the construction shown in Fig. 1 where the filtering
material occupies a horizontal position instead of a vertical one.
In constructing the well I form the same of blocks of porous earthenware as
illustrated in Figs. 3 and 4, the former being used as a foundation block and the
latter for the walls. The foundation block underlies the walls and may be from
two to six inches in thickness. The wall blocks preferably of segmental form, are
cemented to the foundation block and to each other. As a cement for this
purpose I prefer to use asphaltum applied hot. The application is made by lightly
dipping the impinging surfaces of the blocks after they have been fitted into the
hot asphaltum and quickly laying them upon the slab or upon each other before
the asphaltum has time to cool. This secures water-tight joints and prevents the
entrance of water except through the blocks as desired. The asphaltum forms
a durable water-tight joint and is not liable to crumble or decay as is mortar or
stone or earthy cements.
"
Wells bored by "augers" or otherwise of dimensions too small to allow of
walling in the manner before described are lined with tubes of porous earthen-
ware, which may be made in sections or lengths convenient for handling, say
twenty-four to thirty inches in length more or less, and in diameter suited to the
diameter of the hole made in the ground, the former preferably somewhat less than
the latter. With either the porous tubing or the walls of porous blocks, gravel or
clean coarse sand, or both may be and preferably is introduced and packed into
the space between the tube or walls and the surrounding earth, which packing
serves to support and hold this well lining securely in place and also to impede
the entrance into the interstices of the porous earthenware of fine particles of
dirt or dust, which might in time impair the filtering qualities of the porous
earthenware. Coarsely broken charcoal may also be used in connection with or
instead of sand.
It is obvious that the porous earthenware is as applicable to the construction of
.reservoirs located in wet ground as to ordinary wells.
It is also obvious that said material is adapted to the construction of small
filters for household use as well as to large cisterns or wells as hereinbefore
described. For small filters the second form of porous earthenware in which part
of the imprisoned sawdust is reduced to charcoal is preferred.

page_text: Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. A filtering cistern or receptacle provided with a false bottom of porous
earthenware whereby a large quantity of water may be quickly and effectually
filtered.
2. A filtering cistern or receptacle provided with a false bottom of porous
earthenware acting as a filtering means as described and with loose filtering material
resting on and supported by said bottom.
3. A filtering cistern or receptacle provided with a false bottom of porous
earthenware acting as a filtering means as described and with layers of gravel and
sand supported by said bottom.
4. A well built of porous earthenware as distinguished from ordinary earthen-
ware, for filtering the water passing into the same.
5. A well, the walls and bottom of which are built of porous earthenware as
distinguished from ordinary earthenware, said porous walls and bottom serving to
filter the water passing from the surrounding ground through the same into
the well.
6. A well built of pieces of porous earthenware as distinguished from ordinary
earthenware, said pieces being united by asphaltum joints so as to prevent the
water from passing from the surrounding earth into the well except through the
porous material of which it is built.
7. A filtering material consisting of porous earthenware combined with
charcoal.
8. A filtering material consisting of porous earthenware having comminuted
charcoal imbedded therein.
9. A filtering material consisting of porous earthenware, a portion or section of
which is combined with charcoal.
10. A filtering material consisting of porous earthenware, the inner or inter-
mediate portion or section of which is combined with charcoal.
11. A filter, well, or cistern provided with a filtering material consisting of
porous earthenware intimately combined with charcoal.
Dated this 11th day of May 1886.
HERBERT J. ALLISON,
Agent for the Applicant.