That double trigger guard leads me to believe that there had to have been a trigger in the second one. The backwards-looking trigger may have been an early fire-selector.
Interesting concept, though. The spring mechanism transforms it into sort of like a hand-held Gatling gun, only with a revolving chamber instead of revolving barrels. It does get away from having to deal with the engineering and timing of a gas-operating system. On the other hand, it's hard for me to imagine that a clockwork-powered operating mechanism would stand up to the rigors of military usage. And given that the .44 Henry and the .56 Spencer metallic cartridges were already developed by 1863, a front-loading repeating rifle had to have been seen, even then, as a technological dead end.