5FoS:

Steam powered gatling dart gun. Steam drives it and acts as propellant for darts. You can see the boiler and coal furnace at the bottom, and the coal bin in front of it. Water can to the left.

I've been trying to find out what they would have used for an animal tranquilizer around 1900, (for a label on the dart hopper. I may be overdoing this. ) but have been coming up empty. If anyone has any idea, Id be endebted to you. Closest I could find was a sodium bromide broth.