There was the fabulous Icteneo (“new fish”), invented by Narcis Monturiol and launched in 1864. A full-size replica of the Ictineo can be seen in Barcelona.

Le Plongeur (“the diver”), invented by Captain Simeon Bourgeois and launched in 1863, it was the first submarine to be powered by mechanical means: a compressed-air engine operating a reciprocating engine. It was also the largest submarine built up until that time.

American inventor Ross Winans built the first of his remarkable “roller ships” at Ferry Bay, Baltimore, in 1858. Newspapers of the time rhapsodized how it “will inaugurate a new era in naval architecture.”

It had no keel, no masts, no rigging…not even a deck (in lieu of which the ship had a flattened space about 16 feet long to which were riveted four settees). Instead, it was a streamlined cigar-shape. Perhaps its strangest feature was the ring-shaped propeller that circled the waist of the ship.

All suffered from the same problems: weak rudders, rolling and excessive water breaking over their bows. After struggling with it for two years, Winans finally abandoned the annular propeller.

Via io9.