The same consideration applies to ship design. You cannot have everything. If you attempt it, you will lose everything; by which I mean that in no one quality will your vessel be as efficient as if you had concentrated purpose on that one. On a given tonnage,—which in ship-building corresponds to a given size of army or of fleet,—there cannot be had the highest speed, _and_ the heaviest battery, _and_ the thickest armor, _and_ the longest coal endurance, which the tonnage would allow to any one of these objects by itself. If you try, you will be repeating Richelieu’s mistake when he tried to carry on offensive war on four frontiers. The fighting order of navies still continues a line; which is called more properly a column, because the ships are ranged one behind the other. Nevertheless, if the arrangement of the guns, from van to rear, is regarded, it will be seen that they really are deployed on a line fronting the enemy. As a rule, in instructed naval warfare, attack has been on one flank of that line. It is commonly spoken of as an attack on van or rear, because of the columnar formation of the ships, but it is really a flank attack; and, whichever flank is chosen, the attack on the other is essentially refused, because the numbers devoted to it are not sufficient to press an attack home. The culmination of the sail era—Trafalgar—was fought exactly on these lines. Nelson concentrated the bulk of his fleet, a superior force, on the left flank of the enemy, which happened to be the rear; against the right flank he sent a smaller number. He did not indeed give specific orders to the smaller body not to attack, or to refuse themselves. That was not his way. Moreover, he intended himself to take charge of this attack in smaller force, and to be governed by circumstances as to the development of it; but the result was shown in the fact that the larger part of the enemy’s right flank escaped, and all probably would if they had maneuvered well. The hostile loss fell on the other flank and on the center; and not only was this the case in result, but also Nelson in form and in his orders purposed just this. He put the concentrated attack in the hands of his second; “I,” said he, in effect, “will see that the other flank of the enemy does not interfere.” Conditions modified his action; but that was his plan, and although, from the particular conditions, he actually pierced the enemy’s center, still, having done so, the subsequent attack fell upon the flank originally intended, while the other flank was kept in check by the rear ships of Nelson’s own division. These, as they advanced in column, lay athwart the line by which the enemy’s van, if it tacked, would approach the rear, or other flank; and they thus prevented its approach by that route until too late to be effective.