And here we leave the region of material. I have built the process up stage by stage as it was argued out, but of course all the processes proceeded in simultaneous relation, and the result was to show a great possibility. Something like the ship described above could be made if it were wanted. Was it wanted? Was it the right thing to make? Was its tactical value sufficient to justify the increase in cost and all the changes in design? We must turn for the answer to the tactical sphere. Here I felt able to see a little more clearly. As cannot be too often repeated, war is all one; and the same principles of thought which are true in any form are true _mutatis mutandis_ in every other form. Obviously in creating an Army or an Air Force or a squadron of battleships you must first of all have regard to their highest tactical employment, namely, decisive battle. Let us, therefore, first of all visualise the battle. Let us try to imagine what its conditions will be; what we shall have to meet and what would help us most to win. The first naval idea of our supreme battle at this time was that it would be fought about something: somebody would want to be going somewhere and somebody else would try to stop him. One of the Fleets would be proceeding in a certain direction and the other Fleet would come along and try to prevent it. However they might approach, the battle would soon resolve itself into two lines of ships steaming along parallel and bringing all their broadsides to bear upon each other. Of course if one Fleet is much stronger than the other, has heavier guns and shoots better, the opposite line begins to get the worst of it. Ships begin to burn and blow up and fall out of the line, and every one that falls out increases the burden of fire upon the remainder. The Fleet which has more ships in it also has a tail which overlaps the enemy, and a good many ships in this tail can concentrate their fire upon the rear ships of the enemy, so that these unlucky vessels have not only to fight the ships opposite to them, but have to bear the fire of a number of others firing obliquely at them from behind. But smashing up the tail of an enemy’s Fleet is a poor way of preventing him from achieving his objective, i.e. going where he wants to go. It is not comparable to smashing up his head. Injuries at the head of the line tend to throw the whole line into confusion, whereas injuries at the tail only result in the ships dropping astern without causing other complications. Therefore the Admiralissimo will always try to draw a little ahead if he possibly can and bring his van nearer and nearer to the enemy and gradually, if he can, force that enemy to turn off, so that he can then curl round him. This well-known manœuvre is called ‘Crossing the T,’ and Admiral Togo had used it in the battle of the Sea of Japan.