photo 
Early warning system
Early warning system
"Acoustic listening devices developed for the Dutch army as part of air defense
systems research between World Wars 1 and 2," but does it float, 16 December 2009 :: via swissmiss
There's a lovely Dr. Seuss-ish quality to these physical amplifiers. Sometimes this is how I feel — one ear to the sky, one ear to the ground, listening for what's out there.
Nate: 