Arithmetic of electricity;
A practical calculation manual for electricians, engineers and students, written by T. O'Conor Sloane and published by N. W. Henley in New York in 1903. The figures are coarse ink line diagrams of wire cross-sections, circular-mil packing grids and numbered conductor rows, with dotted measurement rules and a Franklin profile trademark from the advertising pages; useful for concentric-circle motifs, technical annotation and small-scale engraved portrait marks.
