Astrolabij quo primi mobilis motus deprehenduntur canones
This 1512 Venetian printed treatise on the astrolabe, by Robertus Anglicus, active 1326, was issued from the press of Petrus Liechtenstein for scholars and practitioners of astronomy and instrument making. Its woodcut diagrams show geometric figures, a figure measuring a slope with a sighting device, and a man observing a tower and a sun ray, offering designers clear, schematic line drawings of measurement and observation.
