Unique Rotary Spark Gap

The parts necessary to construct this rotary gap are as follows: A small motor, a sheet of brass 6 inches square and 1/8 inch thick, two large binding posts, a piece of brass 5x1x1/8 inch, a piece of brass rod 6 or 8 inches long and 1/8 inch in diameter. A — Stationary electrodes, which are cut out of the square sheet of brass. B — Rotating bar, which is fastened on the motor shaft. C — Hard rubber knobs. D — Large binding posts. E — Brass rod.
To operate this gap the rod which is fastened on A is put through the hole in the binding post and then adjusted as near the rotating bar as seems best, and to be found by test. The motor can be a common battery motor.

Contributed by JOHN WEBER, JR.