The ascending scale is easier for purposes of study; the mind grasps smaller things more easily, and they prepare the way for the appreciation of the greater things. But it is not by a process of logical development that we reach blockade after a study of contraband. Blockade is treated last more conveniently because it involves the greatest development of force against the enemy; but it would have been more logical to have begun at the other end of the scale, starting with the greatest exhibition of force, and letting the series of rules emerge in diminishing strength. In view of what remains to be said, it is of great importance to appreciate that the incarnation of sea-power, blockade, which cuts the enemy off absolutely from the outer world, lies at one end of the scale of what one belligerent may do to the other, and the seizure of contraband on a neutral ship going to an enemy port, which cuts the enemy off but partially, lies at the other end. There can then be no difficulty in justifying what comes in between. But the most curious point is that it is only when we come to the recognition of this extreme manifestation of force that we meet with artificial rules. A blockade must be ‘effective.’ Yet this word, as to the meaning of which in its ordinary use there can be no doubt, is given in treaties and by the authorities a wholly artificial meaning. Sometimes it includes the exact contrary to effectiveness, as that ‘A blockade is not regarded as raised if the blockading force is temporarily withdrawn on account of stress of weather’[21]: during which the adventurous skipper may run in. It is not necessary to labour the point; but it is necessary, when measures short of ‘blockade’ have been taken by England, that the full extent of what blockade pressure upon neutral trade means should be understood. In order to determine what characterises a blockaded port, that denomination is given only where there is, by the disposition of the Power which attacks it with ships, stationary or sufficiently near, an evident danger in entering.[22] A blockade [by cruising squadrons allotted to that service, and duly competent to its execution] is valid and legitimate, although there be no design to attack or reduce by force the port or arsenal to which it is applied, and that the fact of the blockade, with due notice given to neutral Powers, shall affect not only vessels actually intercepted in the attempt to enter the blockaded port, but those also which shall be elsewhere met with and shall be found to have been destined to such port, with knowledge of the fact and notice of the blockade.[23] These two quotations embody the principles of the English prize law. Article 17 of the Declaration of London contains a modification of them, and provides that ‘neutral vessels may not be captured for breach of blockade except within the area of operations of the war-ships detailed to render the blockade effective.’