An interesting piece of science equipment, believed to date from the 19th Century. First invented in the 1600s, it is used to create a vacuum and demonstrate atmospheric pressure. These are likely to have been kept in schools or universities to demonstrate to students.
The two parts are made of heavy brass with a metal lining. They are in good condition for their age with no damages. The brass has tarnished and slightly pitted over time but overall they display very nicely.
Total Length together : 9 1/2" (24cm)
Diameter : 3 3/4" (9.5cm)
I see no reason why it shouldn't work as intended but I have not tested it and it is being sold as a collectors item rather than a working scientific instrument. The best description comes from the photos so please look at them all carefully and if you have any questions please ask