before that new fangled invention, radar, there existed the wonderful invention of early warning listening devices (!), the sound mirror. I have a thing for sound, noises and so on and always found these fascinating. but i thought Professor Mayer's topophone would amuse and delight you. and you have to see the combat cutlery on the museum of retro technology
Ah-HAH. That link to 'Professor Mayer's topophone' etc DOES have a picture of those tuba-things the Japanese used. Damn, those are cool. Crazy, crazy looking things.
I also want those flintlock cutlery. I would train myself to flip them around in my fingers and fire at those foolish enough to insult me at the dinner table.
Edit: Also, that wall at the bottom of the page? Impressive.
Professor Mayer's Topophone does indeed amuse and delight me, though I must say I'm partial to the RRH myself. The compressed air amplification stuff is fantastic. The ear piercing, horn amplified cello! The twin gramophone with crossfader valve!!