§ 182. One mode of attack which was in use at the time of sailing ships, namely, boarding and fighting the crew, which can be described as a parallel to assault in land warfare, is no longer used, but if an instance occurred, it would be perfectly lawful. Attack is nowadays effected by cannonade, torpedoes, and, if opportunity arises, by ramming; and nothing forbids an attack on enemy vessels by launching projectiles and explosives from air-vessels, provided the belligerents are not parties to the Declaration--see above, § 114--which prohibits such attacks. As a rule attacks on merchantmen will be made by cannonade only, as the attacking vessel aims at seizing her on account of her value. But, in case the attacked vessel not only takes to flight, but defends herself by a counter-attack, all modes of attack are lawful against her, just as she herself is justified in applying all modes of attack by way of defence. As regards attack by torpedoes, article 1 No. 3 of Convention VIII. of the Second Peace Conference enacts that it is forbidden to use torpedoes which do not become harmless if they miss their mark. [Sidenote: Submarine Contact Mines.] § 182_a_. A new mode of attack which requires special attention[359] is that by means of floating mechanical, in contradistinction to so-called electro-contact, mines. The latter need not specially be discussed, because they are connected with a battery on land, can naturally only be laid within territorial waters, and present no danger to neutral shipping except on the spot where they are laid. But floating mechanical mines can be dropped as well in the Open Sea as in territorial waters; they can, moreover, drift away to any distance from the spot where they were dropped and thus become a great danger to navigation in general. Mechanical mines were for the first time used, and by both parties, in the Russo-Japanese War during the blockade of Port Arthur in 1904, and the question of their admissibility was at once raised in the press of all neutral countries, the danger to neutral shipping being obvious. The Second Peace Conference took the matter up and, in spite of the opposing views of the Powers, was able to produce the Convention (VIII.) concerning the laying of automatic submarine contact mines. This Convention comprises thirteen articles and was signed, although by some only with reservations, by all the Powers represented at the Conference, except China, Montenegro, Nicaragua, Portugal, Russia, Spain, and Sweden. Most of the signatory States have already ratified, and Nicaragua has since acceded. The more important stipulations of this Convention are the following:--