Gerbert
By some authorities accredited with the invention of the escapement and the application of the weight as a motive power for clocks. He was born in Belliac, in Auvergne, in 920 A. D. He was educated in a monastery, and served successively as Monk, Bishop, Archbishop and finally as Pope, being better known under the name of Sylvester II. He died May 12, 1003.