Presenting A Super Phone System of Inter-Office Communication

Boston: Holtzer-Cabot, 1940. Paperback. Very Good. Paperback. An advertising piece for an early executive control system from Holtzer-Cabot Electric, a Boston company specializing in motors, telegraphs and telephones, and fire alarm systems. They closed in 1972. A four-page folder on card stock with pictures of the phones and speaker, and a detachable postcard for requesting more information. Very good condition. Science and technology SCI/020215.