Diving/smoke helmet, 1820-1830.

UNITED KINGDOM - JUNE 10: Diving helmet made by Augustus Siebe, which was probably used by the Deane Brothers of Deptford, London. Augustus Siebe (1788-1872) a pioneer of early helmet diving. He made the first 'open' helmets for the Deane brothers in the 1820s, later patenting 'closed' helmets (also known as �Standard Dress� apparatus). John and Charles Deane were commissioned by the Admiralty in 1832 to work on the possible removal of the wreck of the �Royal George� from the Solent. The brothers made numerous dives to the wreck until 1839, recovering various items in the process, and also discovered the wreck of the Mary Rose. (Photo by SSPL/Getty Images)