The principle of heavy guns being superior at long range is exemplified by the Sketches 1 and 2. Sketch 1 represents the manner in which a salvo of guns may be expected to spread if all the sights are set to the same range. All guns lose in range accuracy as the range increases, but light guns more than heavy. If six 6-inch guns are fired at a target at 12,000 yards the shell will be apt to be spread out as shown in the top line. Six 9.2’s will fall in a closer pattern, as shown in the second line, six 12-inch in a still smaller space, and the 13.5 in one still smaller. Regarded simply as instruments for obtaining a pattern at a given range, heavy guns are, therefore, far more effective than light ones. [Illustration: Big guns more accurate at long range, because more regular] But this is far from being the heavy guns’ only advantage, as will be seen from Sketch 2. The heavier the projectile is, the longer it retains its velocity. The angle at which a shot falls from any height depends solely upon its forward velocity while it is falling. Sketch 2 shows the outline of a ship broadside on to the enemy’s fire, the shell being fired from the right-hand of the sketch. A is the point where the ship’s side meets the water. If the gun were shooting _perfectly_ accurately and was set to 10,000 yards, all the shots would hit at this point. And clearly any shot set at a range greater than this, but one which did not carry the shot over the target, would hit the ship somewhere between the points A and X. Now if a 6-inch shot grazes the point X and falls into the water, it falls at the point B beyond the ship. But the angle at which it is falling is so steep that the difference in range between the point A and the point B is only forty yards. To hit, then, with a 6-inch gun the range must be known within forty yards. This interval is called the “Danger Space.” [Illustration: Big guns need less accurate range-finding, because the danger space is greater] The 9.2 will fall at a more gradual angle, and the shot grazing on X will fall at C, which is twenty yards beyond B; and a 12-inch shell, falling still more gradually, will fall at D, which is 100 yards from A; and similarly the 13.5 at E, which is 150 yards beyond it. Hence, at any given range, far _more accurate knowledge_ of range is necessary for hitting with a 6-inch gun than with a 9.2, with a 9.2 than with a 12-inch, and with a 12-inch than with a 13.5. But we have seen from Sketch 1 that, in proportion as the range gets long, so does the range accuracy of the gun _decrease_, and that this loss of accuracy is greater in small guns than in bigger. To hit with it at all a more perfect fire control is necessary, and for any given number of rounds a much smaller proportion of hits will be made. The advantage of the big gun over the small, merely as a hitting weapon, is twofold. It does not require such accuracy in setting the sight, and more shots fired within these limits will hit. FIRE CONTROL