A difference in errors, for instance, in the relation of 9 to 8, under the conditions mentioned above, between two fleets having an equal number of similar ships, would give one side twice as many hits as the other in any given length of time.
In March, 1905, the writer published an essay in the _Proceedings of the U.S.Naval Institute_ called "American Naval Policy," in which the effect of initial superiority in gun-fire was shown in tables.

One table showed that an initial advantage of only 10 per cent secured an overwhelming victory by an accumulative effect.
Now a difference of 10 per cent in hits, under conditions in which the hits were about 10 per cent of the maximum, would mean, roughly speaking, the difference between 10 hits and 9 hits in a given length of time, or a difference between 90 misses and 91 misses; a difference in errors made of a little more than 1 per cent.
The conclusion to be drawn is too obvious to be stated.

Perhaps the conclusion is not broadly new; but possibly the idea is new that so small a difference in errors made will, under conditions of sufficient difficulty, produce such a tremendous difference in results.
Now, a division is more complex and more difficult to handle perfectly than is a battleship; a squadron more so than a division; a fleet more so than a squadron; a navy more so than a fleet.
_Necessity for Knowledge of the Naval Machine_ .-- There is no machine or tool so simple that knowledge of it is not needed in order to use it skilfully.

This does not mean that intimate knowledge of the details of construction of a machine is necessary in order to operate it; it does not mean, for instance, that a sharp-shooter must have a profound knowledge of the metallurgy of the metal of which his gun is mainly made, or of the laws of chemistry and physics that apply to powder, or of the laws of ballistics that govern the flight of the bullet to its target.

But it does mean that any skilful handler of any machine must know how to use it; that a sharpshooter, for instance, must know how to use his machine--the gun.
Of course, a sharpshooter's skill is exercised in operating under very limited conditions, the conditions of shooting; and it does not include necessarily the maintenance of his gun in good condition.
The operating of some machines, however, includes the maintenance of those machines; and a simple illustration is that of operating an automobile.