"We also thought we had a better torpedo than you had--that it would run farther, straighter, keep depth better, and do more damage when it struck. I still think we have something of the best of it on that score, though at no time was our superiority so great as we reckoned. Your torpedoes ran better than they detonated, and--especially in the first two years--a very large number of fair hits on all classes of our lighter craft were spoiled by 'duds.' This, I am sorry to say, was not reported nearly so frequently during the last year and a half. [Illustration: "HERCULES," WITH THREE V-CLASS DESTROYERS IN KIEL HARBOR] "But it was on the torpedo that we counted to wear down the British margin of strength in capital ships to a point where the High Sea Fleet would have a fair chance of success in opposing it. We expected that our submarines would take a large and steady toll of any warships you endeavoured to blockade us with, and that they would even make the risk of patrol greater than you would think it worth while to take. Although we made an encouraging beginning by sinking three cruisers, we were doomed to heavy disappointment over the U-boat as a destroyer of warships. We failed to reckon on the almost complete immunity the speed of destroyers, light cruisers, battle-cruisers, and even battleships would give them from submarine attack, and we never dreamed how terrible an enemy of the U-boat the destroyer--especially after the invention of the depth-charge--would develop into. As for the use of the submarine against merchant shipping, to our eternal regret we never saw what it could do until after we had tried it. If any German had had the imagination to have realized this in advance, so that we could have had a fleet of a hundred and fifty U-boats ready to launch on an unrestricted campaign against merchant shipping the day war was declared, I think you will not deny that England would have had to surrender within two months.