Reference: H17
Category: Heat
Purpose: Demonstrates increased pressure due to vaporisation.
Description: A small quantity of water above the mercury in a barometer tube. The whole surrounded by a steam jacket. Attach the latter by means of a rubber tube to a copper water boiler. As the barometer tube warms up, the vapour pressure of the water pushes the mercury level down to about the bottom of the steam jacket. Approximately 70cm. Do not use the "good" rotary pump for evacuation barometer tube as mercury vapour has a bad effect on rotary pumps.
