Rivista di astronomia e scienze affini, 1913, a. 7, n. 09 (September)
An Italian astronomy journal issue from September 1913, issued by the Società astronomica italiana and the Turin astronomical observatory for working astronomers and students of celestial mechanics. The pictures are plain line diagrams of geometric constructions: a point P and a centre S linked by lines and arcs, with labelled triangles, sectors and a vertical axis. A designer might take their clean hand-drawn linework and sparse labels as a model for technical diagrams.
