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When at the ballgame, when the roof is closed and the action is a bit slow you might be able to use the spectator's head in front of you as a temporary unipod,…be polite… ask first! along with the offering I'll buy ya a beer!
Another master of the inquisition invented a unipod -- a stool with one leg -- sometimes placed in the middle of the seat, sometimes on the edge, on which the unfortunate scholar tiresomely balanced.
Customs and Fashions in Old New England Alice Morse Earle 1881