Thus from the first day that this method of convoying ships was adopted it was an unqualified success in defeating the submarine campaign. By August 1, 1917, more than 10,000 ships had been convoyed, with losses of only one-half of 1 per cent. Up to that same date not a single ship which had left North American ports in convoy had been lost. By August 11th, 261 ships had been sent in convoy from North American ports, and of these only one had fallen a prey to the submarines. The convoy gave few opportunities for encounters with their enemies. I have already said that the great value of this system as a protection to shipping was that it compelled the under-water boats to fight their deadliest enemies, the destroyers, every time they tried to sink merchant ships in convoy, and they did not attempt this often on account of the danger. There were destroyer commanders who spent months upon the open sea, convoying huge aggregations of cargo vessels, without even once seeing a submarine. To a great extent the convoy system did its work in the same way that the Grand Fleet performed its indispensable service--silently, unobtrusively, making no dramatic bids for popular favour, and industriously plodding on, day after day and month after month. All this time the world had its eyes fixed upon the stirring events of the Western Front, almost unconscious of the existence of the forces that made those land operations possible. Yet a few statistics eloquently disclose the part played by the convoy system in winning the war. In the latter months of the struggle from 91 to 92 per cent. of Allied shipping sailed in convoys. The losses in these convoys were less than 1 per cent. And this figure includes the ships lost after the dispersal of the convoys; in convoys actually under destroyer escort the losses were less than one-half of 1 per cent. Military experts would term the convoy system a defensive-offensive measure. By this they mean that it was a method of taking a defensive position in order to force the enemy to meet you and give you an opportunity for the offensive. It is an old saying that the best defensive measure is a vigorous offensive one. Unfortunately, owing to the fact that the Allies had not prepared for the kind of warfare which the Germans saw fit to employ against them, we could not conduct purely offensive operations; that is, we could not employ our anti-submarine forces exclusively in the effort to destroy the submarines. Up to the time of the armistice, despite all the assistance rendered to the navies by the best scientific brains of the world, no sure means had been found of keeping track of the submarine once he submerged. The convoy system was, therefore, our only method of bringing him into action. I lay stress on this point and reiterate it because many critics kept insisting during the war--and their voices are still heard--that the convoy system was purely a defensive or passive