_Hussar_, Austrian war-ship, Martin Koszta, an American citizen taken and detained on, iii. 385; on demand of Captain Ingraham of the _St. Louis_ is given up, _ib._ Hutter, Midshipman, killed while assisting the Union wounded out of the _Congress_, iv. 209. _Hyder Ali_, American privateer, Captain Joshua Barney, attacks and captures the _General Monk_, i. 212–215. _Illinois_, United States battle-ship, iv. 534, 536. Impressment, feeling of American seamen regarding the practice of, ii. 18. _Independence_, American privateer, Commander Thomas Truxton, cuts out three big ships from the British fleet, i. 205. _Indian Chief_, Confederate ship, iv. 499. _Indiana_, United States battle-ship, iv. 534. _Indianola_, Federal armored gun-boat, in attack on Port Hudson, iv. 352; captured and sunk by the Confederates, _ib._ Indians, friendship of, cultivated by England to injure United States, i. 383; incited by British to attack pioneers, _ib._ Ingraham, Captain Duncan Nathaniel, demands the surrender of Martin Koszta, an American citizen detained on the Austrian war-ship _Hussar_, iii. 385; medal presented to him by Congress, 386. Inland navy an imperative necessity to reach the heart of the Confederacy, iv. 241. Inman, Lieutenant William, chases and captures a pirate schooner, iii. 335. _Insurgent_, French frigate, Captain Barreaut, captures the American ship _Retaliation_, i. 316; battle with the _Constellation_, 320–322; surrenders, 321; lost at sea, 330. International law, a question of violation of, iv. 160. _Intrepid_, formerly the _Mastico_, used as a fire-ship at the attack on Tripoli, i. 371; explodes, 378. _Investigator_, Federal merchant-ship, captured by Confederate cruiser _Sumter_, iv. 415. _Iowa_, United States battle-ship, iv. 534, 536. Ironclad warfare, superior activity of the Confederates in preparing for, iv. 184. Ironclads, the Confederate Government the first to construct, iv. 185; the _Merrimac_ launched, 188; Congress makes appropriation for construction of, 190; dilatory action of Naval Board in making contracts for, 191; first battle between, 220. _Iroquois_, United States screw sloop, built, iv. 16. _Iroquois_, Federal screw corvette, iv. 314. Irving, Washington, on Perry’s victory on Lake Erie, ii. 338. _Isaac Smith_, Federal war-ship, in the Port Royal fleet, iv. 164. Island No. 10, strongly fortified by the Confederates, iv. 275; Foote’s flotilla arrives in front of, 276; capture of, delayed two weeks by Foote, 281; Captain Walke successfully runs the gauntlet of batteries on, 282, 283; the island captured, 283, 289; has disappeared under action of the current, 284. Isle-aux-Noix, British fort at, iii. 136, 139.