Diving helmet made by Siebe-Gorman & Company Ltd, 19th century.

Diving helmet, 19th century.

Diving helmet, 19th century.

Early helmet for closed diving dres, 1839.

Early helmet for closed diving dres, 1839.

Breathing apparatus with full-face rubber mask, c 1980.

Smoke billowing from a circus stuntman as h

Augustus Siebe, German-born inventor of the closed diving helmet, c 1840.

Diving, old Westminster Bridge, London, 1861.

Charles Deane's diving demonstration at Portsmouth, c 1830.

Diving for the wreck of the 'Eurydice', 1878.

"Peress' 'Tritonia' diving suit, 1935."