[General view of some of the dial equipment, Trafalgar Central Office.]

[District selector frame in a dial exchange.]

[Telephone operators.]

[General view of sender frames in a panel dial central office.]

[Telephone operators.]

[Overseas switchboard at 32 Avenue of the Americas.]

[Telephone operators.]

[People observing telephone operators.]

Communications, Telephone Exchange.

Communications, Telephone Exchange.

Communications, Telephone Exchange.

Telephone, New York Telephone Co. Exchanges.

Telephone, New York Telephone Co. Exchanges.

Communications, Telephone Exchange.

[Early types of switchboards, Old Spring Exchange.]

[Early types of switchboards.]

A Program of Lectures

Marconi, Wireless Telegraphing.

Marconi, Wireless Telegraphing Apparatus.

Communications, Telephone Exchange.