First published in 1893 under the title 'The Iron Pirate' this is a rip-roaring, maritime adventure stuffed to the gills with thud and blunder and a body-count in the hundreds. Gods! this is a violent book. One character gets blown in half in the middle of a conversation and countless unarmed others are machine gunned, bludgeoned, and drowned by the ruthless pirates terrorising the Atlantic in their amazing gas-powered phosphor-bronze super-dreadnought.
Our protagonist is a feckless youth who stumbles upon the secret of the pirates and their Nemo-like leader but the gloss is slightly taken off his role as hero when he spends a lot of time not informing on the Nemolike leader and his crew to the authorities - because he has given his word not to. Thus making him an accessory before the fact to the sinking of at least one British Navy ship and the deaths of a lot of people. Twat. And I'm not sure I want to know where he was hiding his colt revolver between being kidnapped from the streets of New York, stripped of all his possessions and thrown in an open boat - and his arrival at the pirates' secret base up a fiord in Greenland. I thought it best not to enquire.
There was a sequel (also available on Archive.org), 'Captain Black; a romance of the nameless ship.'