Alarming

Subway train drivers in Tokyo are woken every day in
their depot dormitory by a pillow that automatically
inflates at the appointed time. Aristotle 'slept little, and
always had one arm out of his couch with a bullet in it,
which by falling into a brazen basin underneath, early
awakened him' [Lempriére]. Salvador Dali apparently
took naps on the same principle, with a teaspoon and a
pewter dish; Thomas Edison, while having big thinks,
kept a lead ball in his palm, the idea being that it would
fall on his foot if he dozed off. There is a certain bird that
stands on one leg clutching a stone in the raised foot, so
that when the stone drops the bird wakes.