Vintage and Antique Whistles
Whistles are simple machines with few or no moving parts. In most cases, the sounds they make are activated entirely by air pressure, produced by nothing more than a human breath. Blow into a whistle softly and it makes barely a sound, but put your lungs into it and you will produce a screech that's attention-getting enough to stop most people in their tracks. How a whistle produces a sound is tricky to explain, but it goes something like...