Before long the two midshipmen were aboard the monitor "Nevada" and were talking with Captain Brice. At first the latter was utterly opposed to any "monkeying," as he expressed it, with one of his guns. Finally he became interested in Robert's earnestness, and relented to the extent of the following ultimatum: "Now, Mr. Drake, I'll allow you to remove the present sights of one of my six-pounders; the sights are kept out of the gun, anyway, for that matter; and in their places you may put in new sights. But you are not to alter the gun in any way; you must fix it so that any sights you put in can be immediately replaced by the regular sights. I'll send for the man you want, Lenn, and tell him to give you a hand." Chief Gunner's Mate Lenn soon appeared, and he and the two midshipmen repaired to the forward starboard six-pounder on the superstructure deck, where Robert explained what he wanted. Lenn grasped the idea with avidity. "Why, Mr. Drake," he said, "we can fix up what you want with no trouble at all. A sight is a simple thing--the principle is that the centre line of the gun's bore must be exactly parallel to the line of sight at point-blank range with no speed allowance. Now you want a peep-sight. We'll get a hollow cylinder, say an inch in diameter, and an inch or two long; we'll plug the end and drill a fine hole in the end of your plug. There's the peep. And the forward sight will be a ring with cross wires in it. Now your line from the peep-hole to the cross wires must be parallel to the axis of the gun. And while I think of it the rear and front sights should be as far apart as possible; I'll tell you what we'll do; we'll carry the sight at the end of a long piece of brass pipe; I've just the stuff in my storeroom. I'll fit a Y piece to where the present front sight is, pivot it there and hang the forward part of the pipe in its gimbals. I'll just run a quarter-inch pin through the pipe; and I'll drop the rear end of the brass pipe on this rear sight--I'll have to make a slight alteration in this rear sight----" "You can't change a thing, Lenn, you mustn't," interrupted Robert. "Captain Brice will not allow any changes of the gun----" "Oh, I've an old condemned rear sight below; I'll use that," smiled Lenn. "Now we'll fasten our new front cross wire and rear peep-sights to the ends of our brass pipe--why, anybody can see at a glance it will be a far better arrangement than the present poor system." When Robert and Peters left Lenn said: "Come aboard the 'Nevada' in two days from now and you'll find your new sights on this gun ready for business."