Coffman Engine Starter

These devices were (are) a study in cleverness.  The goal: start a large (generally aircraft) engine without incurring a large weight penalty vis-a-vis an electric motor and battery set.  The cardboard cylinders are, roughly speaking, blank-type shotgun shells.  They contain a fairly slow-burning propellant.  When the operator desires a start, a shell is discharged, the gas spinning up a small turbine.  A gear reduction unit and engageable pinion couples this energy into the engine’s flywheel or similar.  The pictured unit is a multiple-discharge-type, allowing convenient retries in the event of a failure to start, or subsequent stall.