CHAPTER X
FIRST BLOWS FROM THE AIR
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-maché, 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.
The Flying Fish was driven by nine propellers, three of these, four-bladed and six feet diameter, revolved a little forward amidships on either side under what might be called the fins. These fins collapsed close against the sides of the vessel when under water and expanded to a spread of twenty feet when she took the air. They worked on a pivot and could be inclined either way from the horizontal to an angle of thirty degrees. Midway between the end of these and the stern was a smaller pair with one driving screw. The eighth screw was an ordinary propeller at the stern, but the outside portion of the shaft worked on a ball and socket joint so that it could be used for both steering and driving purposes. It was in fact the tail of the Flying Fish. Steering in the air was effected by means of a vertical fin placed right aft.
She was submerged as the Ithuriel was, by pumping water into the lower part of her hull. When these chambers were empty she floated like a cork. The difference between swimming and flying was merely the difference between the revolutions of the screws and the inclination of the fins. A thousand raised her from the water: twelve hundred gave her twenty-five or thirty miles an hour through the air: fifteen hundred gave her fifty, and two thousand gave her eighty to a hundred, according to the state of the atmosphere.
Her armament consisted of four torpedo tubes which swung at any angle from the horizontal to the vertical and so were capable of use both under water and in the air. They discharged a small, insignificant-looking torpedo containing twenty pounds of an explosive, discovered almost accidentally by Castellan and known only to himself, the German Emperor, the Chancellor, and the Commander-in-Chief. It was this which he had used in tiny quantities in the experiment at Potsdam. Its action was so terrific that it did not rend or crack metal or stone which it struck. It overcame the chemical forces by which the substance was held together and reduced them to gas and powder.
And now, after this somewhat formal but necessary description of the most destructive fighting-machine ever created we can proceed with the story.