A blockade, such as we maintained around Cuba, is established by stationing war vessels at the entrances of harbors and at intervals along the blockaded coast.  Its purpose is to cut off supplies and stop all communication with the enemy by sea.  The merchant ships of all nations are therefore forbidden to pass or even to approach the line, and the penalty for disobedience is the confiscation of both ship and cargo—­whether the latter is contraband or not here makes no difference.  If the ship does not stop when hailed she may be fired upon, and if she is sunk while endeavoring to escape it is her own fault.  And unlike vessels merely guilty of carrying contraband, she is no less liable to seizure on her return voyage, after her cargo has been disposed of.  Altogether, blockade running is perilous business.  It is usually attempted under cover of night or stormy weather, and it is as full of excitement and adventure as war itself.  The motive is usually either to take advantage of famine prices, or to aid the enemy by bringing supplies or carrying dispatches.

Neutral ships, however, are entitled to some sort of warning that a blockade exists.  Notice is therefore sent to all neutral governments, announcing the fact and stating exactly the extent of coast covered.  Besides this, until the blockade has lasted for some time and thus has become generally known it is customary for the officers of the blockading fleet to visit and warn every ship that approaches, the warning, with the date, being entered upon her register.  If, after that, she approaches the forbidden coast, she is liable to confiscation—­though possibly great stress of weather might excuse her provided she landed no cargo.  Instructions of this sort were issued by President McKinley to our squadron blockading Cuba.  A reasonable time, also, was granted to ships that were lying in the blockaded ports at the time when the blockade was declared, to make their escape.  President McKinley allowed thirty days for this purpose, which was unusually liberal.

Nations engaged in war have sometimes assumed that they could establish a blockade by simply issuing a proclamation forbidding neutrals to approach the enemy’s coast, without stationing ships to enforce it.  For example, during the Napoleonic wars, France declared the whole coast of England to be blockaded at a time when she scarcely dared send out a ship from her ports, having been soundly thrashed at Trafalgar.  But these “paper blockades” are a mere waste of time and ink.  They are not valid, and except in the way of angry and contemptuous protest, no nation would consider them worthy of the slightest attention.  If Spain, for instance, should attempt a desperate game of bluff by declaring New Orleans, New York and Boston under blockade, all neutral ships would come and go just the same, and she would meddle with them at her peril.  This question—­if it ever was a question—­was finally decided by the epoch-making convention of the powers at the