Central Telephone Office and Exchange

Perspective view of the Parisian central telephone office and exchange of avenue de l'Opéra, showing a host of busy switchboard operators and a cutaway depiction of the cables running beneath the floor, down to the basement, to connect to the rosace room. At the time the book was written, this particular office employed an all-female staff, including thirty-three switchboard operators and a director.

The caption reads in the original French: Bureau central téléphonique de l'avenue de l'Opéra.