According to the folks over at prc68.com The Fullerphone is a way to send Morse code using either a pair of wires or a single wire and an Earth ground path. The Mark V model was also capable of carrying voice transmissions. This is some early 1900s technology here in action at the Reading Air Show I visited earlier in the year. I promised you more images as the season wore on and I always try to deliver. If you are viewing this on Facebook please feel free to share this post.
If you’d like a print you can always order from my online store.