material through these grooves or channels, the interior of the shells
is lined throughout with plates or strips of brass that fit very closely
together, and present a simple slit with chamfered edges opposite the
grooves. At the two joints of the shells four of these plates are
riveted two by two; all the others are movable, and rest, like the
pieces of an arch, against the fixed plates that form abutments. Each
half lining is thus held by means of a central plate, b' (Fig. 10), with
oblique edges, and which, being driven home by the top of the filter,
binds the whole tightly together. All these plates, which are slightly
notched at their upper part, rest on a small flange at the lower part of
the shells.

[Illustration: FILTERING PRESS FOR OLEAGINOUS SEEDS.--AUTOMATIC
INJECTION PUMP]

As regards their manufacture, these plates are cut out of sheets of
perfectly laminated brass, and are afterward set into a matrix to center
them properly. After the shells have been bored out, all the plates are
mounted therein so as to obtain a perfectly cylindrical and uniform
surface. The plates are then numbered and taken out; and, finally, a
slit with chamfered edges is cut longitudinally through them, save at
three points--two at the extremities and one at the middle. The plates
thereafter rest against each other only at these three points, and leave
at the chamfered places capillary openings just sufficient to give
passage to the oil, but not to the pressed paste, however fine it be.
As will be seen in Fig. 5, the points of contact are not in the same
horizontal plane, but are arranged spirally, so that the flow will not
be stopped at this place as it would be were these solid parts all at
the same height. The filter, F, is completed by two pieces that play an
important part. The first of these is a cast iron rim, J, which is set