A collection of diving helmets and equipment is to cross the block at Bearnes Hampton & Littlewood in Exeter, UK on June 15.
It was acquired over a number of years by diving enthusiasts Anthony and Yvonne Pardoe.
A 12-copper helmet with welding visor by Siebe Gorman & Co is among the headline lots, with an estimate of £3,000-4,000 ($4,248-5,664).
Augustus Siebe (1788-1872) invented the closed diving helmet in the 1830s, revolutionising the safety of underwater work.
The present lot is a rare matching numbers example.
Also on offer is a triple cylinder single action diver's pump designed by Siebe.
It carries an identical estimate of £3,000-4,000 ($4,248-5,664).
It would have been used to provide divers with air while underwater and operates by means of a hand crank.
A diver attending the pre-sale exhibition explained to ITV News why modern equipment is superior: "You're not dependent on a pipe, a pump, attendants, and clammy death equipment. You can't see much at all.
"I mean you've got that tiny little window, and it's all by touch and feel. The men who used these were real men."
However, while the equipment may look anachronistic, the famous US Navy Mark V diving helmet is still in production today and remains popular with commercial divers.
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