The arguments in favor of these vessels as stated by the friends of the system were as follows: Frigates draw so much water and need so much sea-room for all manœuvres that they are utterly helpless in the shoal waters of the American harbors, while the gun-boats are moveable batteries, capable of going anywhere in any harbor that has three feet of water in it. The gun of the gun-boat was as efficient as any of the best guns of the largest ship afloat, so forty gun-boats would have among them a more efficient battery than the _Constitution_, or any other frigate afloat. In a contest between forty gun-boats and a frigate, the boats would have the broadside of the ship--say 1,500 to 2,000 square feet of surface--for a target, but the boats would fight her end on, and so each would present to her a target but ten feet wide (at most eighteen feet wide) and but two feet out of water. The gun-boats would be scattered around the frigate and so the gunners would have to aim at the little targets separately. The gun on the boat being low down near the water, had a better chance of hitting the frigate (and at the water-line) than a high gun had of hitting a low target. [Illustration: Old-time Naval Gunnery. _From a wood-cut._] If a shot fired at the hull of a frigate happened to fly too high it might still seriously injure the rigging and spars, but if a shot was fired at the gun-boat and bounded over the hull it would do no damage because the spars of the gun-boat were not for use in time of battle. If a frigate lost her masts or her rudder she was helpless, but a gun-boat, having many oars, could surely be managed as long as she floated. The gun-boats were cheap to build--seventy-five of them cost no more than one good frigate, or say $4,000 each. On the whole the building of gun-boats certainly was a plausible scheme in the eyes of a landsman, especially as the first argument--as to the depth of water and sea-room required for a frigate--was unanswerable. But when the men who knew the sea looked upon the plan it made them sick at heart. The mere idea of proposing to protect the lives and liberties of the people of the nation from foreign aggression by inviting the enemy to come into our harbors to fight, was enough to make any patriot sick at heart. But that was only one point against the system. Considering the physical qualities of the supposed combatants, when forty boats attacked a frigate the ship did, indeed, show a broadside of 2,000 square feet, while the gun-boat was only ten feet wide and two feet high out of water. Even at that the aggregate length of water-line of all the boats when standing precisely end on to the frigate was four hundred feet. But the boats could not and never did remain end on. They had to fire over one bow or the other, so the target that each presented was much more than ten feet wide and two high, and, what was worse, the gunners of the high-decked frigate could look down on the deck of the gun-boat.