[Illustration: FIG. 2.]

This difference in tension is utilized for balancing at every instant
the weight of the ribbon unwound, and thus causing the float to
immerse itself in the water to a constant degree. The ribbon, B, is
provided throughout its length with equidistant apertures that exactly
correspond to tappets that project from the circumference of the
wheel, R. When the float moves its position, the wheel, R, begins to
turn and carries along in doing so the pinion, w, which revolves
over the toothed wheels, s1, s2, and s3. The thickness of w
is equal to that of the three wheels, s1, s2, and s3, and a
special spring secures at every instant an intimate contact between
the pinion and the said wheels. These latter are insulated from each
other and from the axle upon which they are keyed, and communicate,
each of them, with conductors, I., II., and III. They are so formed
and mounted that, in each of them, the tooth in one corresponds to the
interspace in the two others. As a result of this, in the motion of
the pinion, w, the latter is never in contact with but one of the
three wheels, s1, s2, and s3.

If we add that the lines, I., II., and III. are united at the shore
station with one of the poles of a pile whose other pole is connected
with the earth, and that w communicates with the earth through the
intermedium of R, and the body of the apparatus, it is easy to see
that in a vertical motion of the float in one direction we shall have
currents succeeding each other in the order I., II., III., I., II.,
etc., while the order will become III., II., I., III., II., etc., if
the direction of the float's motion happen to change.