Use a 30ml., a 10ml. piston and a short piece of tubing
Connect the tubing to the 30ml. piston
Push the plunger of the 10ml. piston in and then connect to the tubing
Pull the plunger of the 10ml. piston out and in and explore this pneumatic system
Notice that the 30ml. piston does not respond instantaneously because air is a “spongy” fluid and compresses – watch carefully as the delay is very slight!