NATIONAL TELEPHONE COMPANY
B310

Battery Wall Set

Pattern No. B310

Comprises - Granular Carbon Transmitter, Watch Receiver, Cord, Automatic Switch-hook, Induction Coil, Bell, and Push Button.

This is an obliquely mounted Set on a bracket, and is a very suitable instrument for some special situations.

Was B51 in the 1903 Catalogue.
 

Last revised: February 19, 2026