Crookes tube with a Maltese Cross
Crookes tube with a Maltese Cross. (Crookes nr 9) The tube demonstrates that electrons go in a straight line and don’t go through metal. The cross can actually lay down and stand up (mechanically). When the cross lies down, the glass face of the tube emits a green glow when the electrons strike the glass wall, when it’s right up you will see the shadow of the cross.