"That to constitute a violation of a state of blockade, three things must be proved: first, the existence of the blockade; secondly, the knowledge of it, in the party supposed to have offended; and thirdly, some act of violation, either by going in, or coming out with a cargo, laden after the commencement of the blockade." [Sidenote: First Rule of Blockade.] I. There is no rule of law more established than this; that the Breach of a Blockade subjects the property so employed to confiscation. Every man knows it; the subjects of all states know it. A lawful maritime blockade requires the actual presence of a sufficient force stationed at the entrance of the port, sufficiently near to prevent communication. The blockade is to be considered legally existing, although the winds may occasionally blow off the blockading squadron. It is an accidental change which must take place in every blockade; but the blockade is not therefore suspended. This axiom is laid down in all books of authority; and the law considers an attempt to take advantage of such an accidental removal as an attempt to break the blockade, and a mere fraud.[185] When a blockading squadron is driven off by a superior force, the blockade is effectually raised, and it must be renewed by fresh notification, before foreign nations can be affected by an obligation to observe it as a blockade. The mere appearance of another squadron will not renew it, but it must be restored by the measures required for the original imposition of a blockade.[186] [Sidenote: Second Rule of Blockade.] It is necessary that the evidence of a blockade should be clear and decisive. A blockade may exist without a public declaration; although a declaration, unsupported by fact, will not be sufficient to establish it. In the War of 1798, the West India Islands were declared under blockade by Admiral Jervis; but the Lords of the Supreme Court held, that as the fact did not support the declaration, a blockade could not be deemed legally to exist. But the fact, on the contrary, duly notified on the spot, is of itself sufficient; for public notifications between governments are meant for the information of individuals; but if the individual is _personally_ informed, that purpose is better obtained than by a public declaration.[187] Where the vessel sails from a country lying near enough to the blockaded port to have constant information of the blockade, no notice is necessary of its continuance or relaxation; but when the country is at a distance beyond constant information, they may lawfully send their vessels on conjecture that the blockade is broken up, after it has existed a long time.[188] And this is important, as it must be remembered that even the _intention_ to evade blockade is a fraudulent breach of it, and sailing towards the port is an _overt_ act of that intent.[189]