With refinements in Agatan Gear Theory and the ever increasing precision of measuring tools, the late 1500s saw a widespread interest in clockwork machinery for everything from toys to basic amenities (see: the AutoSignatour, 1579). In 1567, a Spanish monk crafted a life-sized mechanical replica of himself to take his place in the monastery during mass and prayer while he was ill or travelling. It was made of wood and iron and stood about five feet tall with fully functioning eyes, mouth, and arms. It rolled about on a number of small, finely shaped brass balls, usually in a circle or a square, driven by key-wound spring that required winding every two hours. Various whistles and flutes built inside the chest were designed so that when air was pushed through by a concealed pump, the resulting whistling sounded close to a certain hymn or chant.