I wonder how it works. Does it fire all three barrels at the same time or does that lever on the side somehow let you cycle through the barrels? Interesting pistol.
You saying that made me think to look it up; this is described as a tap-action, and I found the term means...
Tap actions tended to be smaller pistols, similar to pocket or muff guns. Taps were often used a box-lock design with a single doghead and trigger. A small tap or lever was on the side of the pistol which allowed the shooter to redirect the sparks of the primer to different touch holes.