IMPROVEMENTS IN FILTERING FLUIDS
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN SMALL,
of the Old Jewry, in the City of London, Merchant, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Eighth day of November, in the second year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said John
Small, Her especial licence, full power, sole privilege and authority, that I, the
the said John Small, my exors, admors, and assigns, or such others as I, the
said John Small, my exors, adññors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, the
Invention of "IMPROVEMENTS IN FILTERING FLUIDS," communicated to me by
a certain foreigner residing abroad; in which said Letters Patent is contained
a proviso, that I, the said John Small, shall cause a particular description of
the nature of the said Invention, and in what manner the same is to be
performed, to be inrolled in Her said Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Small, do hereby declare that the nature of the said Invention, and in what

page_text: manner the same is to be performed, are fully described in and by the follow-
ing statement thereof (that is to say)
The filter may be either a square case or a cask, a vase, or anything that
will contain water or other liquids at from two to six inches (according to the
size of the filter) from the bottom. An iron grating or false bottom, thus,
or a wooden one pierced with holes, must be fixed (for very
small filters there is no occasion for a false bottom). Several air
holes must be made in the filter, from the false bottom upwards,
to let out air, and one or more cocks fixed between the bottom and false
bottom of the filter, to draw off the liquids. The ingredients for filtering
consist of cloth shearings, or waste of cotton will also answer when cloth
shearings cannot be procured. The cloth shearings must be prepared as
follows, viz-Make a light infusion of potash, with which wash the cloth
shearings until it is cleansed of a part of the gum which it contains; then
wash it again in water mixed with a good quantity of clay earth, after-
wards wash it well with clean water until the water from it is quite clear.
When the cloth shearings are prepared as above, place a piece of serge
or other cloth on the false bottom of the filter, to prevent the cloth
shearings from escaping. Upon the serge put a layer of cloth shearings of
from six to ten inches thick, and put a sufficient quantity of water on it, so as
to spread and divide them and to imbibe them well. Open the cock, and the
cloth shearings will descend as the water is drawn off. Then an iron grating,
the same as the false bottom, must be placed on the cloth shearings, and well
pressed down with a screw press; they must be kept down by "two bolts,
which are placed across the filter," and then the screw press taken out. Then
put water again, and a second layer of cloth shearings, and proceed as above.
Then a second iron grating, pressed as before, and lastly, a third layer of cloth
shearings, and proceed as above. Upon the whole place a third iron grating,
and press all well down, keeping it down by the press remaining in the filter.
For very small filters there is no occasion for either a false bottom or a grating;
cloth shearings well pressed down will be sufficient. When the filter is pre-
pared as above, the air must be expelled which is in the cloth shearings by
opening the air holes for the first quarter of an hour of filtering; then stop
them with pegs, and commence filtering. When the quantity of liquid
diminishes, or does not run quite clear after filtering for some time, it will be
necessary to take out the cloth shearings from the filter, and to put them in a
basket, and wash them with clean water till they are well cleaned; then place
them in the filter as they were before. Should the top layer only be dirty, it
will not be necessary to take out the under ones. It will not be necessary to