Guinea and Feather Apparatus.
Comprises a guinea & feather, a glass tube 1-metre long x 50mm o.d. with a solid rubber stopper at one end plus a 1-hole rubber stopper at the other end.
A piece of hose is attached to the rubber stopper for connecting to a vacuum pump to evacuate air from the glass tube.
A mohr clip (supplied) is used to seal the rubber tubing once air is evacuated.