Fabrica, et vso del compasso di proportione : doue insegna à gli artefici il modo di fare in esso le necessarie diuisioni, e con varij problemi vsuali mostra l'vtilità di questo stromento
Paolo Casati's 1664 Bologna treatise on the proportional compass teaches craftsmen how to mark divisions on the instrument and solve practical problems with it. Its pictures are geometric diagrams of a circle inscribed in a square with lettered points and dotted construction lines, and a designer could take from them the clarity of labelled construction drawings and the way a compass divides a circle.
