Concentration and Isolation.—­The value of “concentration” is often insisted on, but the author desires to call attention to a misunderstanding on this point, to which he called attention in an essay in 1905.  To the author, it seems that concentration is a means and not an end, and that the end is what he called “isolation” in the essay.  If a man concentrates his mind on any subject, the advantage he gains is that he prevents other subjects from obstructing the application of his mental powers to that subject; he pushes to one side and isolates all other subjects.  In this particular activity it does not matter whether we call his act “concentration” or “isolation” because the whole operation goes on inside of his own skull, and concentration on one subject automatically produces isolation or elimination of all others.  But when concentration is attempted on external objects, the case is very different, for concentration may not produce isolation at all.  For instance, if 4 ships in column A concentrate their fire on the leading ship in column B, the other 3 ships in column B are not isolated, and can fire on the ships of column A, even more effectively than if column A was not concentrated on the leading ship of B, because they are undisturbed by being fired at.  If, however, the 4 ships of A “flank” or “T” the ships of column B, as shown in Fig. 2, and concentrate on the leader of B, they thereby isolate the other ships, and practically nullify their ability to fire at A.

[Illustration:  Fig. 2]

This effect is approximated by an approximate “T-ing” or “flanking,” such as is shown in Fig. 3; because the average distance from the ships of A to the leading ship in B is less than the average distance from the ships in B to any ship in A; and because the direction of fire from each ship in A is more nearly abeam than is the direction of fire from the ships of B.  These positions are very difficult to gain, even if A’s speed is considerably greater than B’s; since all B has to do to prevent it is to head to the right, unless shoals or other dangers such as enemy battleships, C, are on that side, co-operating with A.

[Illustration:  Fig. 3]

An interesting position is that shown in Fig. 4, which may be assumed by A, either for flight, or to get the advantage in torpedo fire.  The advantage is that the A ships are running away from torpedoes fired by B, while B is running into torpedoes fired by A.  This advantage is not great if the distance between A and B is so little that B’s torpedoes can reach A.  But if A is able to make this distance equal to the entire range over which B’s torpedoes can run, or near it, B’s torpedoes cannot reach A at all.

[Illustration:  Fig. 4]