bell, vacuum jar, 6V battery and leads, vacuum pump
Description:
After
carefully
suspending
the
bell
in
the
jar,
connect
the
vacuum
tube
to
the
pump
and
the
battery
to
the
bell.
The
bell
will
immediately
start
to
ring
-
turn
on
the
vacuum
pump
and
the
sound
levels
decrease
dramatically.
PIRA 3B30.30