For centuries inventors have been dreaming up schemes to allow people to submerge beneath the waves, stay a while then return again unharmed. The Resurgam was designed for this purpose, as a stealthy underwater weapon which was the brainchild of an eccentric inventor realised in iron, timber, coal and steam. The inventor was George William Garrett, a curate from Manchester who designed and built the Resurgam submarine in 1879 using the limited technology...