It has been established that six submarines were lost in the barrage and three more so badly damaged that they never again put to sea. However, from further evidence, the British Admiralty officially credit the barrage with fourteen additional, or a total of twenty-three. Two hundred German U-boats were destroyed in the war, or fifty more than the Allies could account for. To err on the conservative side, we claim but eight out of the fourteen credited the barrage by the British Admiralty, or a total of seventeen. This is also the figure arrived at by Captain R. R. Belknap, commander of Mine Squadron 1. What does this figure show? Eight and one-half per cent of the total number of submarines lost during the war were brought into the list of missing by the barrage, which existed for only six per cent of the period of the war. Such results more than justified the effort and time and funds expended. [Illustration: PLANTING MINES IN THE NORTH SEA A squadron of American mine planters at work. Inset: Rear Admiral Joseph Strauss, who was in general command of mining operations.] [Illustration: HOW THE BIG MINES IN THE NORTH SEA BARRAGE WORKED Fig. 1. Mine and Anchor leaving launching rails. Fig. 2. Fifth wheel released, plummet supported by dashpot. Fig. 3. Plummet released and unwinding cord. Fig. 4. Plummet at end of cord. Slip hook pulled off. Fig. 5. Anchor paying out mooring cable as it sinks. Plummet strikes bottom and locks cable drum. Fig. 6. Anchor on bottom submerging mine distance equal to length of plummet cord. A. MINE CASE B. ANCHOR C. PLUMMET D. PLUMMET CORD E. SLIP HOOK F. MOORING] The barrage did more than take toll of submarines sent to kingdom come by its mines. "There is no doubt," reported Sims in the "Summary of Activities of American Forces in European Waters," "that the barrage had a considerable moral effect on the German naval crews, for it is known that several submarines hesitated some time before crossing. Also, reports from German sources are that the barrage caused no small amount of panic in some of the submarine flotillas. It is also probable that the barrage played a part in preventing raids on Allied commerce by fast enemy cruisers." Admiral Strauss, in his testimony before the Senate Investigating Committee, declared that if the Northern Barrage and that across the Straits of Dover had been fully completed as we planned, "it would have ended the submarine menace, so far as submarines going from the North Sea into the Atlantic were concerned;" and that the building of the mine barriers across the Adriatic and Aegean seas, for which we were preparing materials, "would have actually ended submarine operations."