A battalion of Belgian troops on June 14, 1915, gained the east bank of the Yser south of the Dixmude railroad bridge, and established themselves there. The Belgians also destroyed a German blockhouse in the vicinity of the Chateau of Dixmude. The Belgian troops, south of St. Georges, captured a German trench, all the defenders of which were killed or made prisoners on June 22, 1915. After the canal line was won, and the Belgians were in position to hold it, they could make little headway eastward. Their advance was checked by a series of batteries which were concealed in the Forest of Houthulst. These batteries, containing many guns of large caliber, continued to shell the Belgian trenches to such an extent that it was necessary for their inhabitants to keep close to the bomb-proof chambers with which the trenches were liberally supplied. But the Belgians kept so many of the German troops occupied that, in this way, they gave great aid to their allies, and enabled the French and British to regain much of the territory which was lost in the first attack which the Germans made with poisonous gas. The remainder of the summer was occupied with intermittent artillery duels and minor engagements between the opposing trench lines. In the meantime the Belgian army was adding to the number of its troops and gathering munitions for an aggressive movement. PART V--NAVAL OPERATIONS CHAPTER XXVII THE WAR ZONE The war on the seas, with the long-expected battle between the fleets of the great nations, developed during the second six months of the war into a strange series of adventures. The fleets of the British and the Germans stood like huge phantoms--the first enshrouded in mystery somewhere in the Irish and North Seas; the second held in leash behind the Kiel Canal, awaiting the opportune moment to make its escape. These tense, waiting days were broken by sensational and spectacular incidents--not so much through the sea fights of great modern warships as through the adventures of the raiders on the seven seas, the exploits of the submarines, and the daring attempt of the allied fleets to batter down the mighty forts in the Dardanelles and bombard their way toward Constantinople--the coveted stronghold of the Ottoman Empire. The several phases of these naval operations are described in special chapters in this volume, therefore We will now confine ourselves to the general naval developments. In the spring of 1915 the threat made by Admiral von Tirpitz that Germany would carry on war against British and allied shipping by sinking their vessels with submarines, was made effective. The submersible craft began to appear on all the coasts of the British Isles. It infested the Irish Sea to such an extent that shipping between England and Ireland was seriously menaced.