0 a large glass cover shaped like a bell used to cover chemical equipment, especially to prevent any gas from escaping --
His name apparently refers to bell jars.
The table is covered with scarlet velvet, many papers, a casket, an inkwell with two more feather pens, a barometer, a gasometer, a water still and a glass bell jar.
More often, a cloche, or bell jar, refers to a covering made of glass or plastic, placed over individual plants to provide similar protection as row cover.
They also were expensive compared with traditional gardeners' bell jars and cloches.
As the air is pumped out of the sealed bell jar, the noise of the alarm clock fades, thus demonstrating that the propagation of sound is mediated by the air.
A bell jar is placed on a base which is vented to a hose fitting that can be connected via a hose to a vacuum pump.
An example of a classroom science experiment involving a bell jar is to place a ringing alarm clock under the bell jar.
A bell jar demonstrates the reason for using a rocket instead of a propeller in the vacuum of space.
