From the Blackbird journal:
Driven by a key-wound spring, the monk walks in a square, striking his chest with his right arm, raising and lowering a small wooden cross and rosary in his left hand, turning and nodding his head, rolling his eyes, and mouthing silent obsequies. From time to time, he brings the cross to his lips and kisses it. After over 400 years, he remains in good working order. Tradition attributes his manufacture to one Juanelo Turriano, mechanician to Emperor Charles V. The story is told that the emperor's son King Philip II, praying at the bedside of a dying son of his own, promised a miracle for a miracle, if his child be spared. And when the child did indeed recover, Philip kept his bargain by having Turriano construct a miniature penitent homunculus.
"Clockwork Prayer: A Sixteenth-Century Mechanical Monk" (Blackbird)
"A Clockwork Miracle" (Radiolab, thanks Jennifer Lum!)