I made a trumpet marine, or tromba marina from a maple beam, a cello string, a leftover bridge from the 8-bit violin, and a styrofoam cooler as the resonating body. This one’s a bit fancier than the one I made during instrument-a-day 2008.
The tromba marina is fingered below the bow, creating harmonics by lightly touching the string at the nodes. (I tied little bits of thread at the nodal points to make it easier for me to find them.) The bridge is unbalanced so that it vibrates and rattles against the body, making a buzzing sound. It’s an amazingly weird instrument. I love it, but I can’t really play it.
(Here’s a youtube video of a performance with a real Tromba Marina.)