Then: “Navy mine sweepers sent out to destroy mines and floating torpedoes which had missed target—tanker Herbert L. Pratt strikes mine in shallow water on maiden voyage—War Department asks Congress for $10,000,000 to set up balloon and plane stations along the coast to combat sub menace—British steamer Harpathian torpedoed off Virginia capes—American vessel, name withheld, puts back to ‘an Atlantic port’ after being chased by U-boat.” The record continues: “San Diego sunk by mine—tug and four barges sunk—British freighter attacked—sub sends landing crew on board lumber schooner off Maine coast, set her afire—Steamer Merak sunk off Hatteras—tanker torpedoed off Barnegat Bay, beaches blanketed with oil—Norwegian steamer Vinland—British steamer Peniston and Swedish steamer Sydland off Nantucket—nine U. S. fishing vessels off Massachusetts coast—British tanker Mirlo—U.S. Schooner Dorothy Barrett—tanker Frederick R. Kellogg” and so on and on. Events of the time and since have swept these happenings out of the minds of most Americans—even if they knew of it at the time. But somewhere, half forgotten in Naval files, is an official report, painstakingly compiled after the war, from ship logs, from stories by merchant captains and crews, even by officers of surrendered German submarines, to make up as complete a record as possible of one of the amazing operations of the war—and one whose magnitude, in territory covered and damage done, few suspected, even within the Navy, at the time. Only two subs had so much as a brush with American ships. The transport von Steuben, former German liner, proceeding to the rescue of men in life boats from a merchant ship, dropped depth bombs which the U-boat escaped by diving to 83 meters, lying low till the enemy had gone. Closer call had the U-140, largest and most modern of the fleet, which after sinking several ships off Diamond Shoals, including the light ship itself, almost caught a tartar when the Brazilian passenger liner, Uberabe, zigzagging furiously to escape, sent out S.O.S. messages which brought four U.S. destroyers hurrying to the rescue. Nearest was the USS Stringham, which proceeding under full speed, using the Uberabe as a screen, charged on the U-boat, dropped 15 depth charges when the U-boat dived, timed to explode at different levels. [Illustration: Training exercises with U. S. submarines have taught airship captains much about the habits, movements and characteristics of the underseas craft. (U. S. Navy photo).] [Illustration: The year before America got into the last war the German submarine U-51 sank a half dozen merchant ships off Nantucket Island then proceeded into Newport. (U. S. Navy photo)] [Illustration: Navy airships in practice patrols identify, as to class and nationality, all surface ships in their area, learn to recognize the silhouette of a submarine from afar. (U. S. Navy photo)]