John Lethbridge had a lot of mouths to feed. It's said he had 17 children - so he needed to stumble onto a good earner.

It was lucky for him that he was an inventor with real flare. In 1715, he came up trumps with anc early underwater diving machine.

Lethbridge lived in Newton Abbot and he conducted trial runs in his garden pond.

The machine was an underwater oak cylinder with a glass porthole about four inches in diameter.

The diving barrel was 6ft long, and he would lie inside it on his stomach.

There were two holes to stick his arms out, and oiled leather cuffs around the upper arms formed an almost water proof seal.

Lethbridge breathed the air sealed inside the barrel when the lids were locked.

During trials, he found he could stay 12 fathoms underwater for 30 minutes at a time.

When he came to the surface, fresh air would be pumped in through a vent using bellows. At the same time the used air would be let out through a second vent.

Lethbridge came up with his invention because he worked as a salvor for the East India Company.

During his first salvage operation using the machine, he recovered 25 chests of silver and 65 cannons!

There is a section on Lethbridge's work in Newton Abbot museum.

If you want to find out more about his home town, take our tour of Newton Abbot.