Used to have a chem teacher like that
6' something, bald as an eagle, with small round-rimmed glasses.
One day during recess, something went BOOM. Next thing, the window to the chem classroom opens, smoke billowing out. Slowly, that bald head came out, going Heh-Heh-Heh, then just as slowly back inside and he closed the window.
On another occasion, during a test, he put a scale of ether on one side of his bench and lit a burner on the other side. About 10 minutes later, *WHOOSH*. "Alright, time to hand in the papers"...
Probably would get hisself arrested in 10 seconds flat these days :-/
