this, it is an easy step for him to go far out to sea: indeed to be effective blockade mines must be laid where they are least expected. In this war they were frequently so laid.
The most was not, however, made of them. For instance after the first torpedo attack the captain of the Yenesi wished to go and lay mines off all Japanese harbours, but permission was refused him; and though the Japanese laid mines off Vladivostok they did not lay them in effective places.
Though a good many ships were sunk by mines, it was in no case clear that the fatal mines were hostile ones.
As regards the Japanese losses, some of course are not proved to be by mines at all. The Takasago, for instance, which 'struck a mine one dark night off Port Arthur' may very possibly have been torpedoed. If not, the mine is just as likely to have been Japanese as Russian. The loss of the Hei-Yen may also have been by torpedo: at any rate, the ship was within easy radius of Russian torpedo craft. More, then, may have been attributed to mines than was due to them; and of the authentic cases the nationality of the mine is often doubtful.
On the whole it may be said that this was the first war in which the mine appeared as an important factor, although ships had been destroyed by it in the past, especially in the U. S. Civil "War in estuaries and rivers. Neither side can be said to have
