Absolute measurements in electricity and magnetism
A university-level physics textbook by Andrew Gray, published by Macmillan in London in 1921, setting out methods for absolute measurement of electrical and magnetic quantities for students and laboratory workers. The line diagrams show circuits with labelled galvanometers, batteries and condensers, coil windings, and geometric constructions of arcs and angles, usable as clean technical linework and lettered schematic fragments.
