EQUIPMENT
    Siren Disk
    Multiple Hole Air Valve
   


NARRATIVE
            The Siren Disk has four sets of holes at different distances from the center. The disk is attached to an electric motor* which is clamped to the lecture table.  Compressed air is blown through the holes in the rotating disk. The frequency of the sound produced depends on the angular speed of the disk and the group of holes used. The innermost group of holes is unevenly spaced causing noise rather than musical notes.

*The knurled nuts on the motor have left-handed threads.