Of course, the victory will go to the more powerful force; but so many factors go to make up power, that it may be difficult to determine which is the more powerful, until after victory itself shall have decided it. Supposing the skill to be equal on both sides, the victory will go to the side that possesses the most numerous and powerful vessels of all kinds. But unless there is a very great disproportion, it may be difficult to determine which side has the more powerful ships, even though we may know which side has the more numerous. It is extremely difficult to compare even two single war-ships because we do not know the relative values of their factors. Suppose two ships, for instance, to be equal in all ways, except that one ship has ten 14-inch guns, and the other has twelve 12-inch guns of higher initial velocity. Which is the more powerful ship? Suppose one ship has more armor, another more speed. Formulæ designed to assign numerical values to fighting ships have been laboriously worked out, notably by Constructor Otto Kretschmer of the German navy; but the results cannot be accepted as anything except very able approximations. Furthermore, if ship _A_ could whip ship _B_ under some conditions, _B_ could whip _A_ under other conditions. An extreme illustration would be battleship _A_ engaged with submarine _B_ at close quarters; _B_ being on the surface in one case, and submerged in the other case. _Aircraft_.--The influence of aircraft on naval operations is to be very great indeed, but in directions and by amounts that it would not be wise to attempt to predict. The most obvious influence will be in distant scouting, for which the great speed of aircraft will make them peculiarly adapted, as was demonstrated in the battle near the Skagerak. It is the belief of the author, however, that the time is close at hand when aeroplanes and dirigibles of large size will be capable of offensive operations of the highest order, including the launching of automobile torpedoes of the Whitehead type.