Mobility requires a certain maximum speed and also ability to travel a considerable distance, while hunting the enemy. The first requires a certain expenditure, irrespective of the second, and both together, if insisted on in exaggerated amount, mean a very heavy expenditure, to the detriment of fighting power. We should therefore inquire carefully whether they are needed in great amount.

We can perhaps arrive at an answer better by inquiring how much mobility we can afford to give the battleship. It might be said at once that the battleship will not be required to chase small craft, nor fast cruisers, not even the ships of the battlecruiser type. We recognize readily that this is beyond the capacity of the type. What then is she required to chase? There is no other type except her own type. If it should be required that she chase other battleships, then this can be done only in the case of older ships of the type, for, if the higher speed type is approved and copied by other nations, then the difference of speed that makes overtaking possible disappears, and if the type is not approved, the enemy will have instead a type of greater fighting power, for the same expenditure, and it would not be safe to engage in pursuit of such an enemy. There are therefore limitations in the uses of high speed in a battleship.

The question of how much mobility we can afford to give the battleship type depends on what we lose in fighting power when we substitute extreme mobility. There was a time when we were satisfied with fifteen knots in a battleship, as a maximum speed, but we will find that the weight or cost given to the motive power at the time was about the same as we would now give to a modern ship with a higher speed. In other words, maximum speed grows with time, just as size and other qualities do. It is therefore not an absolute figure, but a relative one. It is when we attempt to determine what we gain or lose in fighting power by decreasing or increasing the motive power, that we can arrive at a fairly satisfactory determination of what cost we can afford to stand for motive power.

It has been customary in our usual standard battleship to give about 40 per cent of the displacement to fighting power, represented by armament, armor, and ammunition, and 15 per cent to motive power, the hull making up the remainder. The hull always includes a considerable amount of weight that is strictly

protection, such as the armored decks, and torpedo protection, so that the percentage given to fighting power is really considerably greater than the figures show. If now we take away some of the displacement used for motive power, what can we do with it? Evidently not much, since we could not take very much after all. The ship must have some motive power, and common sense will indicate without any figures at all that we could certainly not take away more than, say, half. Seven per cent of the total added to the forty or more already given to fighting power would not make any startling changes in the power of the battery, the thickness of the armor, or the amount of ammunition, especially as we would want to increase all of these factors at the same time. The loss in motive power represented by the seven per cent would reduce the radius of action to half, and the maximum speed from 21 to somewhere around 16 knots. It does not need any elaborate argument to show that the fighting power does not lose much if we retain the present speed and radius of action, and that there is therefore nothing to be gained by reducing these. The question now becomes, What do we lose when we attempt to increase radically the cost of motive power?

It might here be mentioned, though it should not be necessary, that minor changes from one design to the next, in the quantities referred to, are of no importance, provided they are not progressive. There is no absolute limit in either of the conflicting factors, and one or two per cent one way or the other need not be considered.

We must not, furthermore, take into account large quantities of fuel taken on board for a long voyage, which greatly increase the draft. It is never intended that these should be on board at the time of action, and it is only the weight on board in fighting trim that need be considered. We are not now concerned with any ill effects such extra weights might have on the habitability or seaworthiness of the vessel.

If, now, we should double the allowance given to motive power, we see that the effect on fighting power, if we retain the same total cost, is as great as the effect on the motive power was in the previous instance. The allowance is cut from 40 per cent to 25 per cent, and the effect on each of the quantities included in the general term, fighting power, is serious. We would have

left only about 60 per cent of the previous quantities; thus, the armor would have to be reduced from thirteen to eight inches in thickness, the battery from twelve guns to eight, and the other factors in proportion. Clearly, the effect is not a happy one from the point of view of fighting power. To offset this, we have only increased the maximum speed from 21 to 23 knots, and added a little to the radius of action, hardly a compensating advantage.

In our latest battleships we have increased the speed from 21 to 23 knots. If we had retained the size previously standard, the above would have represented the result. It has been necessary to increase the size and cost of the vessel to obtain this increased speed. Of course there were other increases made, principally in the battery power, but we paid for the increased speed just the same. The size of the vessel was increased over thirty per cent, or by an amount equivalent to nearly the whole of the fighting power of the previous smaller vessel. That the number of guns in the main battery was increased fifty per cent does not imply that the fighting power has been correspondingly increased. The size of the target has been increased, or in other words the ability, and therefore the certainty, of the enemy to increase the number of his effective hits; the efficiency of the three-gun turrets is probably less at medium ranges, from the ballistic standpoint; and we might question whether after all the fighting power has been much increased.

It is to be expected that the size of battleships will increase and continue to increase, and we might expect with each increase of size a small increase of speed, and perhaps of normal radius, but it is natural to assume that the country will expect also a corresponding increase in the fighting power of the larger craft. There is no future limit to the size of the type, nor to the ultimate speed that will be attained, but the country must pay for the total navy finally built, and has a right to expect proper fighting efficiency.

If the above has been the effect of doubling the cost of the motive power, what shall we say of the latest proposition, the so-called fast battleship? Here we have motive power comparable to that of our proposed battle-cruisers, and fighting power distinctly inferior to that of the last class of battleships, the 21knot ships. The displacement is nearly doubled, and the cost,

if the vessel is ever built, will be more than doubled. The result must necessarily be that in the long run, in a given term of years, the fighting power of the entire fleet must suffer. And what would we gain by it? Merely that these vessels, in some circumstances, might run at a higher speed than the rest of the fleet. The offensive power is not greater than that of contemporaries of slower speed, it is measured by the allowance of ammunition, and the use that is made of it. Would this vessel, if she dashes here and there at high speed, making a few hits here and a few there, do a greater sum total of damage than if she settled down to fight an opponent in the old-fashioned way? After all, we are not concerned with an indecisive battle, where there is a little damage done, and a ship sunk here and there. We must consider a battle that will settle, once for all, for that war, the mastery of the seas. For the money that we spend on these vessels, the enemy can put more than twice the fighting power afloat, and where then is our mastery of the seas?

Neither can we consider the possibility of shaking the enemy's morale, by concentrating fast ships on detached portions of his line and destroying them. In the first place, we must expect to meet an enemy as determined as ourselves, and not to be shaken by small losses. In the second place, we can expect him to be equally skillful, and not to leave a few units unsupported. Again, concentration can be of value only at short range, for at long range small differences of distance disappear, and concentration of fire on one ship means that other ships will not get the proper amount of attention. Can we imagine these vessels, lightly armored, and immense targets, coming to close quarters with standard battleships?

In all this discussion, we deal with equal forces on both sides. If we were greatly superior to our opponent, the exact type of ship would be unimportant. If we were much inferior, we would have no chance anyway. The assumption of equal forces appears reasonable. Even if we were slightly superior, we could not give hostages to fortune by wasting fighting power. If the high speed battleship does not seem a reasonable proposition in a general battle, then why the high speed? As we have said before, we would not expect a battleship to chase small craft. We do not use a sledge hammer to smash a fly. It is too slow, and takes too much effort. We get a swatter, a light, quick, cheap

weapon. If the small craft are going to bother us, we can make plenty of swatters, of the requisite kind, out of the fifty millions one of these fast battleships will cost.

It might be said that we need high speed to overhaul the enemy and bring him to action. But we do not build these ships over night. It is a long, painful process, and meanwhile our prospective enemy can build the same kind. Can we ever steal a march on our possible enemies, and build vessels that cannot be copied in sufficient numbers before ours are ready? That has not, with us, been the case in the past, and it will not be in the future. It has not been so with others, except where they had a great building capacity, which means, of course, great available man power.

Again, if we have the superior fighting fleet, but inferior speed, it might be said that the enemy can harry our coasts, and do much damage, before he is brought to action. That has been said many times, and as often it has been answered that such action has no military value, and will not decide the war. There never yet was a case of an inferior, though faster, fleet avoiding contact with the superior fleet. In the end there was either battle or blockade, and one is as effective as the other.

Exceptionally high speed in a battleship, then, seems to be a thing to avoid, and a moderate speed, which will not detract from fighting power, is the correct answer. We might examine, now, the case of a possible exaggeration of the other factor in mobility, namely, radius of action.

To be sure, we have so far not had cause to fear a loss of fighting power on account of an exaggeration of radius of action. In the past, it has usually been the coal pile which has been robbed, when an extra inch of armor was wanted, or an extra knot of speed, or some other showy thing. It might even have been said that we had not had enough radius of action. The radius that appears in the description of a battleship is the radius she has from the time she joins battle, at least that is the intent. It is the radius at normal displacement, which is supposed to be the fighting displacement.

Viewed from this point, it must be admitted that our fuel supply in normal condition has been large enough, and needs no increase. If a vessel gets into action with a normal supply, she will have enough to carry her through the action, and after