Showing Approximate Armaments and Position of Minefields Fig 3-Map of Dardanelles Defences

Owing to separate commands in the different areas, difficulties arose in the co-ordination of the methods of protecting mer chant ships from submarines and by the middle of the year the losses in the Mediterranean became very serious. In August a British commander-in-chief was appointed to Malta as the single authority responsible for trade protection in that sea. A convoy system was started, under the escort of British and Japa nese destroyers and the toll of losses was gradually reduced. A further co-ordination of naval effort followed the meeting of the Allied Naval Council at Malta in November. During the year a British squadron of two battleships and a number of cruisers cruised in the Levant, watching the Dardanelles and co-operating with the Salonika force. On the Palestine coast, a flotilla of monitors, destroyers and gunboats took an active part in the battles of Gaza (q.v.), which led to the fall of Jerusalem (Nov. II).

During 1918 the mine became predominant as a counter to the submarine and a duel developed between the two weapons. The mine barrage in the Dover Straits was strengthened and with the patrol craft armed with every known anti-submarine device nine submarines were accounted for in that area during the early weeks of the year and it became evident to the German naval command that the passage of the Straits was virtually closed to them. They made two attempts to reopen the Straits. On Feb. 15 a destroyer flotilla raided the patrols at night, sank seven drifters and a trawler and escaped without being brought to action. On March 21 a similar raid was not so fortunate, the German flotilla being met by British destroyers. One German destroyer was rammed and cut in half by the "Botha," another was sunk by gunfire and the Germans were chased into Ostend. The "Botha" was torpedoed but reached Dover safely.

Zeebrugge and Ostend.

This proved to be the last German attempt upon the Straits, but as long as their bases at Zeebrugge and Ostend remained in being, raids were to be expected. As early as 1914, Jellicoe had proposed an attempt to block these places, but it was not until the last months of his time at the Ad miralty that active steps were taken to put the plan into execution. Admiral Keyes was appointed to Dover to carry it out. After weeks of secret preparation, the mixed force selected sailed on the afternoon of April 22 to attempt to block the entrances at Zee brugge and Ostend. (See BELGIAN COAST OPERATIONS.) The flo

tilla returned to Dover next morning, its mission at Zeebrugge ac complished. At Ostend the blockships failed to find the entrance, but this was remedied a fortnight later, when a volunteer crew took the "Vindictive," of Zeebrugge fame, into Ostend and sank her in the entrance. These two brilliant actions did not entirely block the Flanders Coast bases, but their moral influence was great and they acted as an added inducement to the German submarines to shun the waters of the Dover command and to confine their efforts to gain the open sea to surmounting the lesser perils of the northabout route.

Last Sortie of the German Fleet.

The Scandinavian con voy remained a bait for the High Sea Fleet and on April 23 it put to sea, for the last time in full strength, to try to intercept it. The date was an unfortunate one for the German enterprise for on that day both outward and homeward bound convoys were in the vicinity of the Forth. The British intelligence system, usu ally efficient, failed this time to warn Beatty that enemy were at sea and the German battlecruisers reached the Norwegian coast at Lat. 6o N. before they were reported. Here the "Moltke" broke down and had to be taken in tow. The German fleet made for home at its best speed; the "Moltke" was torpedoed by Submarine "E. 42" on her way south, but managed to reach her base.

The Northern

Barrage.—Frequent raids were made by the British cruisers and destroyers upon the flotillas engaged in clear ing ways for the German submarines through the minefields and on April 15, during a raid into the Cattegat, 14 German trawlers were sunk. From the commencement of the British intensive min ing policy in the autumn of 1917 until Feb. 1918 over 16,000 mines had been laid in the Heligoland Bight. On Feb. 15 a deep mine field was laid in the Cattegat and the following month saw the beginning of the greatest minelaying operation of the war, the laying of the Northern Barrage. (See article SUBMARINE MINES.) This vast undertaking, the closing by mines of the northern en trance to the North Sea from the Orkneys to the Norwegian coast, involved the laying of over 70,000 mines. The mines were made in the United States and were laid by British and American vessels, escorted by the squadrons of the Grand Fleet, with which for some time an American battle squadron had been working. The Northern Barrage was successful both as a moral deterrent and by the number of submarines destroyed in it.