OTHER DETAILS.
The fly wheel may be a disc of wood.
Oil all the rubbing parts slightly. Connect T1 to one terminal of the
battery, T2 to the coil, and the other terminal of the battery to the coil.
Set the engine going. If it refuses to run, make sure that B1 is pressing
against D. The speed of the engine may possibly be improved by careful
adjustment of B2 and an alteration in the setting of the crank, and will
certainly be accelerated by increasing the number of battery cells.
The cost of the engine described was about 1s, 3d., exclusive of the
battery.
XII. AN ELECTRIC ALARM CLOCK.
Anybody who possesses an alarm clock with an external gong, an electric
bell, and a battery, may easily make them combine to get the drowsiest of
mortals out of bed on the chilliest of winter mornings. The arrangement has
as its secondary advantages and capabilities--
(l) That the clock can be placed where its ticking will not disturb the
person whom it has to arouse in due course (some of the cheaper clocks are
very self-advertising);
(2) That one clock can be made to operate any number of bells in different
parts of the house.
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