will be deflected to a greater angle at high readings than that of the
tangent galvanometer. Consequently, the divisions on the scale will
be widest apart in our instruments, which greatly facilitates high
readings.

* * * * *




SECONDARY BATTERIES.


The Consolidated Electric Light Company has now completed the secondary
battery which has for some time engaged the attention of its officers,
and their regular manufacture and use for electric lighting stations
have been fairly entered upon. Among other places to which the batteries
have been sent and put into work is Colchester, where the company
has for some time had an installation at work, chiefly employing
incandescent lamps. The battery consists of lead electrodes, anode and
cathode being of the same character. They are constructed of narrow
ribbons of lead, each element being made from long lengths of the ribbon
about or nearly 0.20 in. width, rolled together into a flat cake like
rolls of narrow webbing, as illustrated by the annexed diagram, Fig.
1, the greater part of the ribbon being very thin and flat; but
intermediate thicker ribbons are also employed, as in Fig. 2, this
thicker ribbon being corrugated as shown, and affording passage room
for the circulation of the electrolyte. From four to eight coils of the
plain ribbons are between every pair of corrugated ribbons. They are
wound up together tightly, and pressed into the nearly rectangular form