it should be deliberately sunk to get it out of the way. The French boat _Plongeur_, launched at Rochefort in 1863, was cigar-shaped with the upper side flattened, and was driven by an engine deriving its power from compressed air. She was too long for her width to be of much use, and had no stability. The first Confederate _David_ has already been alluded to, and the Southerners were so pleased with the success that they ordered another. In five experiments the second boat sank five times, and drowned altogether thirty-five men. Before she went down the next time it was determined that she should attack one of the Federal warships. She was directed against the _Housatonic_, then one of the fleet blockading Charleston. The _David_ was being navigated along the surface of the water instead of beneath, and her scuttles were open. The little vessel’s spar-torpedo struck the warship in line with the magazine. Nothing was ever seen of the _David_ afterwards, nor of her crew. The _Housatonic_ went down, but nearly all on board were saved. Though the _Davids_ proved as destructive to themselves as to the enemy, they demonstrated as nothing else could have done that a small boat approaching noiselessly under cover of darkness could destroy by means of mines or torpedoes a hostile ship. The most inappropriately named submarine was the _Resurgam_, invented by an English clergyman named Garrett, for during an experiment off the Welsh coast, in 1879, it never returned to the surface after diving.