The World Peril of 1910 by George Griffith

The _Flying Fish_, the prototype of the extraordinary craft which played such a terrible part in the invasion of England, was a magnified reproduction, with improvements which suggested themselves during construction, of the model whose performances had so astonished the Kaiser at Potsdam. She was shaped exactly like her namesake of the deep, upon which, indeed, her inventor had modelled her. She was one hundred and fifty feet long and twenty feet broad by twenty-five feet deep in her widest part, which, as she was fish-shaped, was considerably forward of her centre.

She was built of a newly-discovered compound, something like papier-mache, as hard and rigid as steel, with only about one-tenth the weight. Her engines were of the simplest description in spite of the fact that they developed enormous power. They consisted merely of cylinders into which, by an automatic mechanism, two drops of liquid were brought every second. These liquids when joined produced a gas of enormously expansive power, more than a hundred times that of steam, which actuated the pistons. There were sixteen of these cylinders, and the pistons all connected with a small engine invented by Castellan, which he called an accelerator. By means of this device he could regulate the speed of the propellers which drove the vessel under water and in the air from sixty up to two thousand revolutions a minute.