Show HEAVY FORTRESS I II I HELD IMPREGNABLE I I i MANILA P. P I. I April 23 The The heavy fortifications of ot Corregidor the so- so I called Gibraltar of the orient have I been found technically impregnable when the big guns are assisted by airplanes air air- t pJ planes nes This re result lt is announced after extensive naval l maneuvers during the past three days The naval vessels under command of Admiral Strauss attempted during the three days' days operations to force an entrance entrance to the bay Fourteen destroyers destroy destroy- ers ens supported by a large number of seaplanes seaplanE's participated in the attack Naval aval officials described the maneu- maneu ers as purely routine |