Description

A modern
replacement for
the Bell in a Bell
Jar Apparatus. A
90mm diameter
acrylic tube
houses a batteryoperated,
high
output piezo
sounder. When
the end plates are
attached and the
unit connected to
a vaccuum pump
no sound can be heard but the sound returns
when the air is allowed back in.
An effective demonstration with none of the
complications of the traditional apparatus. Overall
length 150mm.
Vaccuum pump not included.