This was better, so now he tried five yards closer, as it appeared to improve at every advance, and the ball now hit the paper at its lower right-hand edge. Examining the bullet holes in the bark of the tree, and noticing they were all low and all on the right-hand side, Bevis tried to think how that could be. He was quite certain that he had aimed perfectly straight, and as he was now so accustomed to the puff from the priming, that did not disconcert him. He kept his gaze steadily along the barrel till the actual explosion occurred, and the smoke from the muzzle obscured the view. It must be something in the gun itself. Bevis put it on the rest unloaded, aimed along, and pulled the trigger, just as he would have done had he been really about to shoot. Nothing seemed wrong. As the heavy barrel was supported by the rest, and the stock pressed firm to his shoulder, pulling the trigger did not depress the muzzle as it often does with rifles. He aimed again, and all at once he saw that the top sight must be the cause. The twisted wire was elevated about an eighth of an inch, and when he aimed he got the tip of the sight to bear on the paper, so that, instead of his glance passing level along the barrel, it rose slightly, from the breech to the top of the sight. The barrel was more than a yard long, so that when the top of the sight was in a line with the object, the muzzle was depressed exactly an eighth of an inch. An eighth of an inch at one yard, was a quarter at two yards, three eighths at three yards, at four half an inch, at eight it was an inch, at sixteen two inches, and at twenty-four three inches. This was very nearly enough of itself to account for the continual misses. In a gun properly made, the breech is thicker than the muzzle, and this greater thickness, like a slight elevation, corrects the sight; the gun, too, is adjusted. But the matchlock was the same thickness from end to end, and till now, had not been tried to determine the accuracy of the shooting. Bevis got a file and filed down the sight, till it was only a sixteenth of an inch high, and then loading again, he aimed in such a way that the sight should cover the spot he wished to strike. He could see both sides of the sight, but the exact spot he wanted to hit was hidden by it. He fired, and the ball struck the paper about an inch below and two inches to the right of the centre. Next time the bullet hit very nearly on a level with the centre, but still on the right side.