Last night, I read a particular bit, a comment made by the story's principle character, Pierre Arronax after his first under-sea walk in his pressurized suit provided to him by Captain Nemo, the commander of the Nautilus. Arronax states that the suit was quite wonderful, and such an improvement upon the cumbersome apparatus of the 18th Century. When I read this, I had to look into it. I did not know much about the history of diving suits, or underwater exploration of this nature.
And so, I found that actually, diving suits or a way of remaining under water for longer periods of time, goes way back. Even the ancients found crude ways of keeping themselves breathing underwater for extended periods, generally keeping a metal or wood bucket over their heads, trapping air, and walking the sea floor. Of course this is in shallow surroundings, not deep sea.
But, in 1715, two Englishmen developed the first "official" diving suit. John Lethbridge's suit was completely enclosed, basically a barrel of air, with a glass port, and two enclosed sleeves. Andrew Becker's was similar, but included a system of tubes for inhaling and exhaling! The diving bell had entered the scene.
At that time, a Frenchman, Pierre Remy de Beauve, designed his "garde de la marine" suit, one of the oldest known diving dresses, equipped with a metal helmet and two hoses, one for air supplied from the surface by a bellows action.
By the late 1790's a German, Karl Heinrich Klingert, fashioned a suit which also included a large metal belt connected by leather jacket and pants.
Interestingly enough, the first practical submarine was tested in 1800! A drawing of it is shown at right. These technologies were truly something incredible for the times. In the modern era, except for something as revolutionary as the internet or the harnessing of nuclear energy, most new inventions, systems, technologies are merely refinements on past investigations. The marine suit, for example, once perfected for sea-going pressure, could be used for space exploration! What will be the next great thing? Who knows. But, it would have to be something quite spectacular, which is not easily found. Most "incredible" things are based on a previous incarnation.