Equally interesting but unfortunately lacking in details are the reports from the Adriatic of submarines fighting submarines. There have been three such duels, in one an Austrian sank an Italian submarine, in another the Italian was victorious, while after the third both were found lying on the bottom, each torn open by the other’s torpedo. As it is a physical impossibility for the pilot of one submarine to see another under the water, it would seem as if at least one of the combatants in each of these fights must have been running on the surface at the time. Both Mr. Simon Lake and the late John P. Holland were absolutely confident that submarines could not fight submarines, that surface craft would be utterly unable to injure or resist them, and that therefore the submarine boat would make naval warfare impossible and do more than anything else to bring about permanent peace. All that can be said at present is that the actual situation is much more complex than had been expected. Submarines have sunk many surface warships but have suffered heavily themselves. The German government has admitted the loss of over a dozen “U-boats,” while the unofficial estimates of their enemies’ run as high as thirty-five or fifty German submarines destroyed or captured. Admiral Beatty’s victorious squadron, pursuing the German battle-cruisers after the second North Sea fight, turned and retreated at the wake of a single torpedo and the glimpse of hostile periscopes. But the submarine has not yet driven the surface warship from the seas and it has signally failed against transports. Its moral effect has been very great: British submarines have terrorized the citizens of Constantinople; while the victories of their beloved “U-boats” have cheered the German people as the victories of our frigates cheered us in 1812, and have been a somewhat similar shock to the nerves of the British navy. But that sturdy organization has recovered from more than one attack of nerves. And as the war goes on, it becomes increasingly clear that it is unfair to expect unsupported submarines, any more than unsupported frigates a century ago, to do the work of an entire navy. Like the aeroplane, the submarine was first derided as useless, next hailed as a complete substitute for all other arms, then found to be an indispensable auxiliary, whose scope and value are now being determined. CHAPTER XIII THE SUBMARINE BLOCKADE “It is true that submarine boats have improved, but they are as useless as ever. Nevertheless, the German navy is carefully watching their progress, though it has no reason to make experiments itself.” ADMIRAL VON TIRPITZ, in 1901. “DANGER! Being the Log of Captain John Sirius by Sir Arthur Conan Doyle.”