What you see pictured above is a Chrysler Air Raid Siren, the most powerful siren in the world. It's the size of a car, measuring near 12-feet in length and standing more than 6-feet tall. It also weighs twice as much as today's typical car. This gigantic siren is powered by an 180-HP Chrysler Industrial V-8 HEMIŽ gasoline engine. The super-duty engine directly drives a three-stage compressor that blows 2,610 cubic feet of air a minute, at nearly 7 PSI, into a giant siren rotor. The compressed air screams through the chopper and out through six giant horns with an exit velocity of 400 miles per hour. The result is an incredibly loud 138 dB sound (measured 100 feet from the siren). The loudness of this siren is unmatched by any other warning device ever sold, ever. It's also considerably louder than the largest steam whistle or horn. As if that were not dramatic enough, the whole unit, engine and all, slowly rotates one and one-half times a minute on its iron turntable base.

The Chrysler Air Raid Siren is so powerful that it can reportedly start fires with just the sound vibrations it produces. It can turn fog into rain, clearing the sky. It can produce an effective 70 dB air raid signal for a distance of two miles, and under proper conditions can be heard 30 to 50 miles away. Its advertised effective range was four miles in every direction. That's a long way!