It was stated unofficially that this new ship of the all-big-gun type rendered obsolescent practically all the battleships of the world with mixed armaments--that is with guns of varying size. The British naval authorities continued to maintain a discreet silence as to the character of the new vessels, and the design, as its main characteristics became known, was assailed with a good deal of criticism. The controversy was at its height when President Roosevelt called upon Commander Sims, the Inspector of Target Practice in the United States Navy, to make a report upon the advantages possessed by the all-big-gun ship of high speed and complete armour protection in view of the criticism of the British design of Admiral Mahan.[13] Commander Sims, who had made a life-study of gunnery questions, prepared a long report describing the character of the revolution in design, and its influence upon the navies of the world. It is interesting to recall some passages from this report, which in its essential portions appeared in the proceedings of the United States Naval Institute, particularly as the British Admiralty have never considered it wise to enter upon a detailed defence of their policy. Commander Sims stated: "Concerning the advisability of building all-big-gun ships, that is, discarding all smaller guns (except torpedo-defence guns) and designing the ships to carry the maximum number of heavy turret guns, these alone to be used in battle against other ships, I think it could be clearly shown that Captain Mahan is in error in concluding that it would add more to our naval strength to expend the same amount of money that the big ships would cost, for smaller and slower ships, carrying the usual intermediate guns (6-inch, etc.); and that, as in the question of speed, this error is due to the fact that much important information concerning the new methods of gun-fire was not considered by the author in preparing his article. (Note.--Unfortunately these methods of gun-fire cannot at present be specifically explained in a published article, as this would involve a discussion of our methods of controlling our ships' batteries, and bringing our ships into action with an enemy.) "I may, however, assure the reader that, from the point of view of the efficiency of gun-fire alone, it would be unwise ever to build a man-of-war of any type whatever, having more than one calibre of gun in her main battery. In other words, it may be stated that the abandonment of mixed-battery ships in favour of the all-big-gun, one-calibre ship was directly caused by the recognition of certain fundamental principles of naval markmanship developed by gunnery officers.