Oh damn, do I remember those mind numbingly boring documentaries on 16mm (or 8mm) film on subjects like Ancient China and Christopher Columbus. I found the movements of the projector alot more fascinating.
In high school (mid 1980s), I do recall the one time for reasons I do not recall, they played for us on the old 16mm projector a series of 1950s instructional films on how to be polite, how to date, etc. The other kids in the class laughed uproariously at the ancient ways of the 1950s, all the overpoliteness of the characters in the films, and the old innocent slang of those days ("Gee", "Golly", etc). I was the only one not laughing. I found the innocence of the films, and the times, quite enchanting.
I believe it was from the Bell Telephone Science Series.
Bell put out some great Christmas specials in the Delaware Valley, There was The Nativity, and The Night Before Christmas. You could see the stings on the marionettes, but I don't remember caring that much. I just pretended I didn't see the strings.
BTW if you want to check out some of those classic films we saw in school check out this site. Those of you who watched Mr Wizard will love it.
http://www.toonarific.com/international.php?lb_letter=&country_id=57&lb_genre=7&mp_showsPage=2