(2) That the destroyer had proved a failure; of the 24 vessels of this type in and before Port Arthur not one made a hit.
(3) That battleships were necessary to successful naval warfare.
(4) That "team work" in armies, as exemplified in the Japanese movements, was a matter of primary importance.
(5) That short range fighting was decidedly not a thing of the past, as had been believed.
(6) That the use of hand grenades promised to introduce a new and particularly horrid form of attack and defense.
(7) That modern fortifications were impregnable to direct assault, however effective a preliminary bombardment.
(8) That the success or failure of sieges of modernly fortified positions depended upon the effectiveness of the engineer, miner and sapper.
(9) That the floating mine was an instrument of destruction against which the most powerful ship was helpless.
(10) Wounds inflicted by modern arms heal readily. While the war had demonstrated anew that one man in five was killed in battle, it had shown that an amazing proportion of the wounded were soon back on the firing line. The clean wound of the steel rifle projectile yielded to treatment even when vital organs were pierced. The medical records of the war were among its most notable features.
Chronology of First Year of War