ports. Before the next case of blockade that can be described as pacific occurred came the Declaration of Paris (April 15, 1856), requiring that blockades to be binding must be effective; that is to say, maintained by a force sufficient that can prevent access to the coast of the enemy. 1860 Some ill-defined measures of blockade followed such as that of 1860, when Victor Emmanuel, the king of Sardinia, joined the revolutionary government of Naples in blockading ports in Sicily, then held by the king of Naples, without any rupture of pacific relations between the two governments; that of 1862 in which Britain blockaded the port of Rio de Janeiro to exact redress for pillage of a British vessel by the local population and at the same time declaring that it continued to be on friendly terms with the emperor of Brazil; and that in 1880, when a demonstration was made before the port of Ulcinj by a fleet of British, German, French, Austrian, Russian and Italian men-of-war, to compel the Ottoman government to carry out the treaty conceding the town to Montenegro, and it was announced that if the town was not given up, by the Ottoman forces it would be blockaded. The blockade that first gave rise to serious theoretical discussion on the subject was that instituted by France in 1884 in Chinese waters. On October 20, 1884, Admiral Courbet declared a blockade of all the ports and roadsteads between certain specified points of the island of Formosa. The British government protested that Coubert had not enough ships to render the blockade effective and that it was therefore a violation of one of the articles of the Declaration of Paris; moreover, that the French government could interfere only with neutral vessels violating the blockade if there was a state of war. If a state of war existed, Britain, as a neutral, was bound to close its coaling stations to belligerents. The British government held that in those circumstances, France was waging war and not entitled to combine the rights of peace and warfare for her own benefit. Since then, pacific blockades have been only exercised by the great powers as a joint measure in their common interest, which has also been that of peace; and in this respect the term is taking a new signification in accordance with the ordinary sense of the word 'pacific'. 1886 In 1886,