When the _Merrimac_ rammed the _Cumberland_, burned the _Congress_, and was fought to a standstill next day by the little _Monitor_, all the world realized that there had been a revolution in naval warfare. The age of the wooden warship was gone forever, the day of the ironclad had come. And a twenty-year-old Irish school-teacher began to wonder what would be the next revolution; what new craft might be invented that would dethrone the ironclad. This young Irishman’s name was John P. Holland, and he decided to devote his life to the perfection of the submarine. Like Robert Fulton, Admiral Von Tirpitz, and the Frenchman who built the _Rotterdam Boat_ in 1652, Holland relied on submarines to break the power of the British fleet. Though born a British subject, in the little village of Liscannor, County Clare in the year 1842, he had seen too many of his fellow countrymen starved to death or driven into exile not to hate the stupid tyranny that characterized England’s rule of Ireland in those bitter, far-off days. He longed for the day of Ireland’s independence, and that day seemed to be brought much nearer by the American Civil War. Not only had many thousand brave Irish-Americans become trained veterans but Great Britain and the United States had been brought to the verge of war by the sinking of American ships by the _Alabama_ and other British-built, Confederate commerce-destroyers. When that Anglo-American war broke out, there would be an army ready to come over and free Ireland--if only the troublesome British navy could be put out of the way. And already the English were launching ironclad after ironclad to replace their now useless steam-frigates and ships-of-the-line. It is no use trying to outbuild or outfight the British navy above water, and John P. Holland realized this in 1862, as several kings and emperors have, before or since. [Illustration: The _Holland No. 1_. Designed to carry a torpedo and fix it to the bottom of a ship, on the general principle of Bushnell’s _Turtle_. Drawn by Lieutenant F. M. Barber, U. S. N., in 1875.] Though his friends in Cork kept laughing at him, Holland worked steadily on his plans for a submarine boat, throughout the sixties. Presently he came to America and obtained a job as school-teacher in Paterson, New Jersey. There he built and launched his first submarine in 1875. It was a sharp-pointed, little, cigar-shaped affair, only sixteen feet long and two feet in diameter amidships. This craft was designed to carry a torpedo and fix it to the bottom of a ship, on the general principle of Bushnell’s _Turtle_. It was divided into four compartments, with air-chambers fore and aft. Air-pipes led to where Holland sat in the middle, with his head in a respirator shaped like a diver’s helmet, and his feet working pedals that turned the propellor.