Thanks Gerard and Patti. More historical detail welcome. It's funny, I vaguely remember hearing stories of many of these inventions, but can't place them at all in time, because that part may not have been emphasized, only the immediate circumstances.
It just occurred to me, thinking of Roger's "tour" of the cannery for Vicki might have gone considering lack of film footage... maybe a stock still picture of a sardine in a can could have been used, while Roger says authoritatively, why yes Vicki, that's one of our sardines, don't touch it, it's slimy.... now let's get the hell out of this place it smells...