And Archimedes, as he was washing, thought of a manner of computing the proportion of gold in King Hiero's crown by seeing the water flowing over the bathing-stool. He leaped up as one possessed or inspired, crying, "I have found it! Eureka!"

Pleasure not attainable according to Epicurus, 11 - Bartlett's Familiar Quotations, 10th ed. (1919)