but the small chance of its occurring can be greatly lessened by the use
of some kind of "cable protector," which will provide for the spark an
artificial path of less resistance than the dielectric of the condenser,
which the cable in fact becomes.

If a fault suddenly develops on a circuit, the chances are it will be
found in a manhole, and an inspection of the cable in the manhole will
generally reveal the trouble without resorting to locating with a
Wheatstone bridge. The cable is often cut through at the edge of the
duct, or damaged by something falling on it, or by some one "walking all
over it." To guard against these, the ducts should always be fitted with
protectors both above and below the cable. The cables should never be
left across the manholes, for they then answer the purpose of a ladder,
but should be bent, around the walls of the hole and securely fastened
with lead straps, that they may not be moved and the lead gradually worn
through.

In telegraph cables, when one or two conductors "go," it will probably
be useless to look for trouble except with instruments; but if several
wires are "lost" at once it will probably be found to be caused by
mechanical injury, which can be located by inspection. If it is ever
necessary to loop out conductors, a joint can be readily opened and the
conductors wanted picked out and connected into the branch cable and the
joint again closed without disturbing the working wires. In doing this a
split sleeve must be used, and the only additional precaution to be
taken is in filling the sleeve to have the insulating compound not hot
enough to melt the solder and open up the split in the sleeve. In
cutting in service on light and power cables it is entirely practicable
to do so without interruption of service on multiple arc circuits, even
those of very high voltage; but they require great precaution and