The telephone system of the British post office. A practical handbook
A practical handbook by Thomas Ernest Herbert, published in London and New York by Whittaker in 1901, explaining the British Post Office telephone system to engineers, operators and telegraph staff. The plates are line-drawn wiring diagrams and sectional views of switchboards, relays, induction coils, bells and handset apparatus, with hand-lettered labels and dotted circuit runs that can be lifted as schematic ornament or technical pattern.
