"Pete," he remarked, "look at this rear sight; it's an open sight--just a mere notch, a groove. And the forward sight is just a sharp point. If I screw my eye up or down, or from side to side, I might think there were many different places the gun would shoot to. When the gun is fired in this exact position the shot is going in only one direction, but I bet you if ten different fellows should aim along these sights as the gun is now and say where the shot was going to hit you would find there were ten different opinions." "Of course there would be," replied Peters in a superior tone; "there always are with open sights; professional marksmen always use peep-sights." "Pete, you're a treasure," cried Robert in enthusiastic approval; "we'll fit peep-sights to this gun, but we'll keep it a dead secret, and when we come to fire our string of shots we'll use our own peep-sights." "How are you going to fit peep-sights to this gun and not have everybody else know about it?" asked Peters dubiously. "And we only practice with this gun; we will actually fire one of the 'Nevada's' six-pounders,--and probably the sight you fitted to this gun wouldn't fit the 'Nevada's.'" "Let's go aboard the 'Nevada'; she's alongside the 'Santee' wharf, and we'll talk to the captain. I know him, and we'll ask him to let us fit up the six-pounder we're going to use. There's a gunner's mate named Lenn aboard that ship who is a great friend of mine; he's awfully handy with tools, and he'll help me." "But, Bob, a captain isn't going to let a midshipman monkey with the guns of his ship." "The 'Nevada' is in reserve with a crew of only thirty-five men on board; she's here for the instruction of midshipmen, and besides, we're not going to make any permanent change; we're going to invent a new six-pounder gun sight; we'll just take off the old sights and put in our own peep-sights; the captain can put the other ones back if he wants to." "You talk as if you had already invented your peep-sights and all you had to do was to put them on. Now let me tell you, Bob, it isn't so all-fired easy. This gun isn't fitted for peep-sights. Another thing, the rear sight is attached here to a graduated bar; it moves up and down according to the distance of the target you are firing at, and it also moves from side to side, to allow for the speed of the ship. Now you're going to have a good deal of trouble to arrange an entire new kind of sights for this gun." "Pete, those are problems that I'm sure can be solved. I don't pretend to say I know just how we can make the change, but I'm going to study the question, and I'm going to get expert help. Now let's go over to the 'Nevada' and talk with Captain Brice; we've got to get his consent first; and then I'll get that smart gunner's mate, Lenn, to help me; he's a very inventive chap. Come along."