Inside the Flashlight

I unscrewed the metal barrel of the pocket flashlight on the desk to see what made the clicker work. Inside sat a tiny copper spring and two smooth batteries. When I pushed down on the spring with my hand, it compressed and snapped right back with a faint ping. I laid the batteries side by side on the blotter pad to examine the polarity marks. Positive facing negative creates the circuit. Once I lined them back up inside and twisted the cap until it clicked, a firm press brought the beam sweeping across the notebook. The connection is solid.