* * * * *


Speaking of steel ropes as transmitters of power, Professor Osborne
Reynolds says these have a great advantage over shafts, for the stress
on the section will be uniform, the velocity will be uniform, and may
be at least ten to fifteen times as great as with shafts--say 100 ft.
per second; the rope is carried on friction pulleys, which may be at
distances 500 ft. or 600 ft. so that the coefficient of friction will
not be more than 0.015, instead of 0.04.

* * * * *




A NEW OXIDE OF COPPER BATTERY.

By MM. F. DE LALANDE and G. CHAPERON.


We have succeeded in forming a new battery with a single liquid and
with a solid depolarizing element by associating oxide of copper,
caustic potash, and zinc.

This battery possesses remarkable properties. Depolarizing electrodes
are easily formed of oxide of copper. It is enough to keep it in
contact with a plate or a cell of iron or copper constituting the
positive pole of the element.