Diving Bell.

Underwater exploration has fascinated us since we first started sailing the seas. The diving bell in one form or another has allowed us to breathe under water. Used by such notables as Alexander the Great, Bernoulli and Pascal, it is essentially a submerged container filled with air, the air pressure holding the water at bay. Our simplified demo contains a bell, syringe, connecting tube and instructions. First draw the air out with the syringe; then place the ball in water and watch it sink. When you inject air slowly back into the ball, it rises.