I have found however some information that seems to indicate that the event did NOT happen. At least not the way Adam remebered it.
First is a poster for the Shrine Circus in Evansville, IN featuring Adam West as Batman. According to the poster the shows ran from November 24-27, (1977) which places it in the correct setting and date.

So far so good. The problem comes via an issue of the Evansville Press dated November 25, 1977 that covered the event. According to the newspaper article Adam West only talked, "there is no act as such" the article read.
http://local.evpl.org/views/viewimage.asp?ID=918048
Could Adam have embelished the story a bit? Purhaps they wanted him to be shot from the cannon but he declined? Does anyone have any further evidence to this event?



