From the posted link:
Overall condition is NRA Antique Fine with 50% original case colors on the frame and breech. Hammer shows about 70% case colors. The barrel is damascus twist with much of its original browned finish showing along with all of the twist pattern in the steel. The action looks as though it has 2 triggers...the forward one is actually what moves the hammer to half #### automatically and unlocks the breech. The rear one is the actual trigger.
I think I read about that sort of system in African safari type books when I was a kid but I didn't bother to fully figure out what they were talking about. Seems a little cumbersome and slow, not to mention confusing in times of stress. Great collector's item though.