Sciathericon. Illustration entitled Sciathericon stellarum fixarum situm qualibet hora demonstrans, a device for showing time by reference to the fixed stars. The larger wheel is a chart of the constellations of the northern hemisphere, the smaller shows signs of the zodiac and is enscribed with the names of various cities from around the world. This is taken from Kircher's Ars magna lucis et umbrae published at Rome in 1646.