Whew. This has been such a hot topic there's no wonder there's some confusion. I even double-posted while trying to edit and answer someone else's question.
I know there's no "contention," but there's been some rapid post crossover confusion.
With that highly-polished "nose cone," I'm not sure you could tell whether the cowling was rotating or not.
In sum:
A "regular" radial aircraft engine has the engine case fixed to the airframe, and the prop attached to the crankshaft. The whole engine does not rotate.
A "rotary" aircraft radial engine has the crankshaft attached to the airframe and the whole engine is connected to the propeller and the whole engine, with the prop, rotates. In the beginning, this arrangement allowed for a lighter engine --that is, a better weight-to-power ratio. At least, "back then." Progressive engineering solutions for "regular" radial engines made this engine obsolete by the mid-thirties or so. I am told that the original Gnome rotary engines were so precisely machined that one could crush a piston in one's hand. These had to be overhauled frequently, and
usually had no throttle.
I do not think any of these engines were-self-starting, but had to have the prop turned by hand. Once it got going, RPM was regulated by turning the ignition on and off. This resulted in the stop-start phenomenon while maneuvering, giving the braap...pause... brapp sound typical of a lot of early airplanes. I imagine, but do not know for sure, that if the "pause" was too long, the engine would stop rotating and you were screwed unless Superman flew out there in mid-air and gave it a spin.
https://www.youtube.com/watch?v=C6xX0zSvp7wA Mazda Wankel rotary engine is not a radial engine, but instead of pistons, has a central rotating displacement portion (rotor) which rotates, performing the functions of intake, compression, power, and exhaust.
http://en.wikipedia.org/wiki/Wankel_engineDon't feel bad about confusing the Wankel with the aircraft rotary engine. They even say in that article: "The [Wankel] engine is commonly referred to as a rotary engine, although this name applies also to other completely different designs. "
Whew.
Terry