In the accompanying cut we bring together a few figures of porcelain
insulators for uncovered wires placed inside or outside of houses.
[Illustration: PORCELAIN INSULATORS FOR TELEGRAPH AND TELEPHONE LINES.]
Figs. 1 and 2 represent simple and double channeled pulleys to be
fixed against a wall, or upon a pole or a door post, by means of nails
simply. Fig. 3 shows a pulley of larger dimensions for iron wires.
Figs. 4, 5, and 6 show perforated insulators, that are quite convenient
for holding and supporting a wire, but which are not convenient to put
in position when the wire is of some length. Fig. 7 shows a device for
protecting a wire that passes through a wall. Fig. 8 shows a support
designed especially for small poles. It may be used either by passing
the wires through the aperture or winding it around the neck of the
bell. Fig. 8 shows a cleft insulator designed especially for fixing a
wire in places where it must form an angle.--_La Nature_.