Laying telephone cables, London, 5 November 1937.

Cros-section of a telephone cable, c 1900.

Submerged repeater (sectioned) for transatl

STC portable sound level meter, 1934.

Dibble's Electrically Propelled Carriage', 1889.

Telephone cable damaged by fusion at Manchester, c 1900.

Telephone cable damaged by fusion at Manchester, c 1900.

Gower-Bell telephone, 1881.

Telephone exchange operators in gas masks, 31 October 1938.

Section of London-to-Liverpool telegraph cable, 1853.

Section of London-to-Liverpool telegraph cable, 1853.

Submarine telegraph cable laid across the River Medina, Isle of Wight, 1878.