I could see no alternatives to very extensive mining, limited only by the number of mines that could be produced. The mining proposed by me was intended to hamper the operations of both surface vessels and submarines. I pointed out that earlier in the War the view had been expressed to me by the Admiralty that we should not risk our cruisers too freely in the North Sea owing to the submarine danger, and that, if we adhered to this policy, it was impossible to insure that the exits to the Fleet bases would not be mined by surface mine-layers, as the _Meteor_ incident had shown, and as was also indicated by the success of our own infrequent mining excursions to the Heligoland Bight. The correspondence resulted in increased activity on the part of our mine-layers, but the success of our work was unfortunately handicapped by defects in the pattern of mine in use at that time, especially as against submarines. In 1917, shortly after my return to the Admiralty, I undertook a very extensive mining policy. In the previous year, during Sir Henry Jackson’s period as First Sea Lord, a new and much improved mine was designed, the trials of which were carried out after I relieved him. This was one of the replies to the submarine. One hundred thousand of these mines were ordered by me early in 1917 to carry out various schemes for mining the Heligoland Bight and the Straits of Dover. Later in 1917, with the assistance of the United States, provision was made for the large mine-field across the North Sea known as the Northern Barrage. It was not until the large supplies of mines became available in the autumn that really effective results against submarines by mining began to be achieved, although the operations of German surface vessels had previously been hampered to a very considerable extent. CHAPTER IX CONTROLLING THE NORTH SEA During the later months of 1915 the Grand Fleet continued to sweep and control the North Sea in spite of the enemy’s efforts to effect attrition by submarines and mines. On October 1st the 3rd Light Cruiser Squadron, with destroyers escorting, left Rosyth and proceeded towards the Little Fisher Bank; on reaching that locality the squadron turned to the north-westward and steered towards Scapa, arriving on the 3rd. The line thus swept was the possible course of enemy mine-laying or other vessels, proceeding towards, or returning from, the vicinity of Scapa and Cromarty. No enemy ships were sighted. On October 2nd the battleship _Barham_, Flagship of the new 5th Battle Squadron, arrived at Scapa.