Waterproof Bells.
In [Fig. 9] is an example of a waterproof bell where the mechanism is almost all entirely encased in a waterproof brass case.
The circuit is made and broken inside the case, but the magnet cores project through it and act on a second armature placed outside. This second armature carries the hammer which strikes the gong and is governed in speed by the contact-breaking armature inside.
Forms of Bell Gongs.
In order to provide a variety of sounds, bells are provided with gongs of various shapes.
[Fig. 10] shows the ordinary form of gong. [Fig. 11], a tea gong; [Fig. 12], a cow gong; and [Fig. 13], a sleigh bell.
Fig. 10 Fig. 11 Fig. 12 Fig. 13
A coil of steel wire is also used, as in [Fig. 14], which on being struck by the hammer gives a pleasant but not loud tone.
