CROOKES TUBE 'MALTESE CROSS', 1930's

Used to demonstrate cathode rays. A negative voltage is connected to the small end and a positive connected to the cross. The tube is evacuated of air, and when the voltage is applied, electrons (cathode rays) travel from the small electrode towards the cross, some hit the cross while others carry on and illuminate the end of the tube leaving a well defined shadow. This was the first cathode ray tube, probably attributed to Johann Wilhelm Hittorf in 1869, the same period as Crookes was experimenting.

A0265