Telephones, their construction and fitting; a practical treatise on the fitting-up and maintenance of telephones and the auxiliary apparatus
A practical handbook by Frederick Charles Allsop, published by E. & F.N. Spon in London and New York in 1892 for telephone fitters and electricians installing early wall sets and battery circuits. The line engravings show wall-mounted instruments, bell boxes, jars of battery cells, plug switchboards and dashed wiring runs with earth labels, giving designers clean technical outlines and schematic diagram conventions.
