De gli horiuoli a sole
A 1616 Italian treatise on sundials by Giulio Fuligatti, printed at Ferrara by Vittorio Baldini for readers of mathematics and instrument making. The pictures are geometric diagrams of circles, chords, perpendicular lines and labelled points, drawn in black line with lettered points and no shading, showing how the sun's path and hour lines were constructed. A designer could take their clean, precise line work and the compass-and-ruler layout of their labelled figures as a model for technical diagrams.
