ft for any reasonable length of time in the toning
bath without the destruction of its appearance, and we cannot but suppose
that a very long immersion results in a complete substitution of gold for
silver.

* * * * *

THE "SENSIM" PREPARING BOX.

Fig. 1 shows a perspective view of the machine, Fig. 2 a sectional
elevation, and Fig. 3 a plan. In the ordinary screw gill box, the screws
which traverse the gills are uniform in their pitch, so that a draught is
only obtained between the feed rollers and the first gill, between the last
gill of the first set and the first of the second, and between the last
gill of the second set and the delivery roller. As thus arranged, the gills
are really not active workers after their first draw during the remainder
of their traverse, but simply carriers of the wool to the next set. It is
somewhat remarkable, as may indeed be said of every invention, that this
fact has only been just observed, and suggested an improvement. There is no
reason why each gill should not be continuously working to the end of the
traverse, and only cease during its return to its first position. The
perception of this has led to several attempts to realize this
improvement. The inventor in the present case seems to have solved the
problem in a very perfect manner by the introduction of gill screws of a
gradually increasing pitch, by which the progress of the gills, B, through
the box is constantly undergoing acceleration to the end, as will be
obvious from the construction of the screws, A and A, until they are
passed down in the usual manner, and returned by the screws, C and C,
which are, as usual, of uniform pitch. The two sets of screws are so
adjusted as to almost meet in the middle, so that the gills of the first
set finish their forward movement close to the point where the second
commence. The bottom screws, C, of the first set of gills, B, are actuated
by bevel wheels on a cross shaft engaging with bevel wheels on their outer
extremity, the cross shaft being geared to the main shaft. The screws, C,
of the second set of gills from two longitudinal shafts are connected by
bevel gearing to the main shaft. Intermediate wheels communicate motion
from change wheels on the longitudinal shafts to the wheels on the screw,
C, traversing the second set of gills.

[Illustration: FIG. 1.--"SENSIM" SCREW GILL PREPARING BOX.]

The feed and delivery rollers, D and E, are ope