bell jarbell jar
a bell-shaped container or cover made of glass, used to keep gases, air, moisture, etc. in or out
also bell glass
A cylindrical glass vessel with a rounded top and an open base, used to protect and display fragile objects or to establish a vacuum or a controlled atmosphere in scientific experiments.
- The experiment is usually performed, in a more striking manner, with a bell-jar and a number of small light wooden balls suspended by silk strings to a fixed frame above the jar, so as to be just in contact with the widest part of the glass.