crossing—service wires.

City conditions—underground systems—various conduits—vitrified clay pipe conduit—vitrified clay or earthenware trough conduit—joints in multiple-duct vitrified clay conduit—concrete duct conduits—methods of laying conduit—method of laying single duct vitrified clay conduit—method of laying multiple duct clay conduit—wooden duct conduits—objection to use of wood; remedy; adaptation wooden built-in conduits; method of installation—wrought iron or steel pipe conduits; method of installation—porcelain bridgework or carriers—cast iron pipe and trough conduit; advantages—fibre conduits; joints—Edison tube system—underground cables—metal sheaths on underground cables—pot heads—General Electric manhole junction box—pot head connections.

Preliminary considerations—electrician's instructions—location of receptacles—ceiling buttons—hallway wiring—selection of wiring system—three wire convertible system—method of wiring—location of panel boards—current required on each floor of building—arrangement of feeders—installation of motors—largest size of feeder permissible—method of cutting pocket in floor—outlet baseboard—completed pocket—how to examine partition interiors—house plan of conduit wiring—attachment of mains to knobs—precautions in making joints—wiring for heating appliances—wiring with combination of moulding, flexible tubing or conduit in non-fire proof building—feeder system for large hotel.

Classification—Carbon flashers—wiring diagram for Dull's carbon flashers—brush flashers—knife flashers—flasher transmission gearing—simple on and off flashers—flash system of gas lighting—high speed flashers—lighting flashers—wiring diagram for flags—diagram showing method of wiring for high speed effects on single lines—method of wiring for a torch—wiring diagram for high speeds—Dull's lightning—script breakers—chaser flashers—thermo flashers—carriage calls—monogram for carriage calls—wiring diagrams for sign illumination—-National carriage call operating keyboard—clock monogram—Bett's clock mechanism for operating electric monogram time flasher—talking signs—two way thermal flasher.

Lightning rods; why sharp points are used; erection—diagram showing principle of air gap arrestor—variable gap arc breaker—location of lightning arrestor—carbon arresters with fuses for telephone lines—ground connection.

Early experiments—theory—description of storage cell—electrolyte—effect of current passing through electrolyte—types of storage batteries—Plant cells—Willard plates; wood separator—parts of "Autex" automobile cells—Faure or pasted type—comparison of Plant and Faure plates—the electrolyte; kind generally used; preparation; test; mixing acid and water; kind of vessel used;—specific gravity table—effect of deep vessel—density of electrolyte—hydrometer syringe—impurities in electrolyte—tests for impurities; chlorine, nitrates, acetic acid, iron, copper, mercury, platinum—old electrolyte—voltage of a secondary cell—charging—connections for charging—charging; first time; period; regulation of voltage—Edison cell data—frequency of charging—cadmium test—emergency connections for weak ignition battery—portable testing instruments—charge indications—two methods of charging from a direct current lighting system—colors of the plates—how best results are obtained in charging—charge voltage—two ways of charging—diagram of charging connections—how to keep charging current constant—tests while charging; after charging—charge indications—behavior of electrolyte during discharge—lead burning outfit—"boiling"; causes—hydrogen gas generator for lead burning—quick charging—charging through the night—charging period for new battery—Willard underhung battery box for automobiles—high charging rates—"National" instructions for taking voltage readings—mercury arc rectifier—capacity—table of capacity variation for different discharge rates—how to increase the capacity—discharging; too rapidly rating; maximum rate—Edison alternating current rectifier—attention after discharging—the battery room—battery attendants—points on care and management—placement of cells—how to avoid leakage—precautions when unpacking cells—assembling cells—connections—precaution in joining terminals—battery troubles—short circuiting; indication; location—overdischarge; buckling—sulphation of plates—data on National cells; American cells; Autex cells—action in idle cell—lack of capacity—how to prevent lead poisoning—low specific gravity without short circuits; causes—treatment of weak cells—pole testing paper—disconnecting cells—sulphuric acid specific gravity table—how to take a battery out of commission—Witham charging board—putting batteries into commission—cleaning jars—table of voltage charge as affected by discharge rate—condensed rules for the proper care of batteries.