al pipe, and are differently arranged in regard to
each other. A more symmetrical disposition of them could, however, be
adopted by placing them zigzag, or in such a way as to form two helices,
one of which would move in a particular direction, and the other in a
different way. The central pipe, furnished with its brooms, being set in
motion by means of a pulley fixed upon its axis (which also carries a
flywheel), the gas, drawn in at the center, and escaping by the holes
made in the pipe, is forced to the circumference of the vessel, where it
passes out.

The effect of this washer is first, to break up the current of gas, and
then force it violently into the water; at the same time sending into it
the spray of water thrown up by the brooms. This double operation is
constantly going on, so that the gas, having been saturated by the
transfusion into it of a vigorous shower of water (into the bulk of
which it is subsequently immersed), is forced, on leaving the water, to
again undergo similar treatment. The same quantity of gas is therefore
several times submitted to the washing process, till at length it finds
its way to the outlet, and makes its escape. The extent to which the
washing of the gas is carried is, consequently, only limited by the
speed of the apparatus, or rather by the ratio of the speed to the
initial pressure of the gas. This limit being determined, the operation
may be continued indefinitely, by making the gas pass into several
washers in succession. There is, therefore, no reason why the gas should
not, after undergoing this treatment, be absolutely freed of all those
properties which are susceptible of removal by water. In fact, all that
is requisite is to increase the dimensions of the vessel, so as to
compel the gas to remain longer therein, and thus cause it to undergo
more frequently the operation of washing. These dimensions being fixed
within reasonable limits, if the gas is not sufficiently washed, the
speed of the apparatus may be increased; and the degree of washing will
be thereby augmented. If this does not suffice, the number of turbines
may be increased, and the gas passed from one to the other until the gas
is perfectly clean. This series of operations would, however, with any
kind of washer, result in thoroughly cleansing the gas. The only thing
that makes such a process practically impossible is the very
considerable or it may be even total loss of pressure which it entails.
By the ne