Actions of electricity
A 1916 American technical manual on electricity by Jesse A. Landis, issued by the U. B. Publishing House in Dayton, Ohio for students and working electricians. Line diagrams printed in black on tan stock show ring armatures wound with hatched coils, lettered N and S pole pieces, dotted flux paths with arrowheads, and schematic circuits: usable stencil-like geometry and arrow vocabulary.
