An interesting addition that I found on Project Gutenberg. One of the The Dreadnought Boys series of children's adventure books by Captain Wilbur Lawton.
The Dreadnought Boys on a Submarine, by Captain Wilbur Lawton, 1911
United States
Lockyer: submarine, 2x torpedo tubes (12x torpedoes), 26kt (surf), 13kt (sub), 3,000hp compressed air propulsion, three propellers
USS Brooklyn: gunboat; name clash with the armoured cruiser ACR-3
USS Louisville: gunboat
Plot Summary: The inventor Lockyer has built a novel submarine but a rival yard who wants to buy the patents and sell the submarines to an unnamed 'Asian power' plots to cripple his submarine during an official Navy trial. Much daring do ensues as they test out the capabilities of the submarine and hunt down the conspirators at land and sea.
The most interesting aspect of the book is the submarine's propulsion system which is quite prescent for some of the developments that have occurred. The boat is powered by a compressed air system that Lawton probably modelled on the Sterling engine. The submarine's engine is started with an explosive gas mixture and then runs off of the compressed air tanks with sufficient capacity to run at cruising speed (about 6kts) for 5 hours. Then the tanks can be refilled from normal atmospheric air via a retractable 20ft tall 'air pipe' and a compressor. I wonder if this is the earliest description of a snorkel-type device?
