A. Place a piece of 5/8-inch carbon in the hole through the bottom
bracket having top end in focal point of reflector and tighten with
set-screw; as this carbon would burn away the light would be raised and
it would therefore be necessary to raise the carbon about every hour, as
the carbon would burn away about one-half inch per hour.
=GENERAL QUESTIONS AND ANSWERS ON ELECTRIC HEADLIGHTS=
33. Q. Describe the passage of the current through the lamp and tell how
arc light is formed?
A. It enters the lamp at the binding posts with the large hole, then to
the top carbon holder, carbon, then into the electrode and holder; from
there to the solenoid and back to the dynamo, leaving the lamp at the
binding post with the small hole in it. The magnetism from the current
while passing through the solenoid attracts magnet in a downward motion,
and it in turn, by the levers on the lamp, separate the carbon from the
copper, thereby forming the arc.
34. Q. Why should sandpaper be used to smooth commutator instead of
emery cloth?
A. In using emery paper a piece of emery might lodge in the grooves
between the commutator segments, and being a conductor of electricity,
causes short. Will also get embedded in the copper and cut the brushes.
Sand will not do this.