ID:
426
Maker's Name:
Max Kohl, Chemnitz
Where made:
Germany
Dimensions:
11 × 12 × 24.5 cm
Air is admitted through a large pipe in the base of the siren, and directed through inclined holes on to a disc puctuated with holes inclined in the opposite direction.The disc rotates. The pulses of air created form an audible tone. The rotating disc is geared to two dials to show the completed revolutions. The count over a known time gives the frequency.
