Electricity simplified. The practice and theory of electricity ..
A popular technical primer on electrical practice and theory by T. O'Conor Sloane, published in New York by N. W. Henley & Co. in 1891 for students, amateur experimenters and tradesmen. The line engravings are schematic: bar magnets and coils drawn as plain rectangles crossed by ruled lines, surrounded by dashed field lines with small arrowheads, plus battery and galvanometer circuits — a source of clean arrow-and-contour diagram vocabulary.
