A remarkable result of long experience of war made itself clearly apparent in the era of Trafalgar. I have already alluded to the tendency to restrict the construction of line-of-battle ships to those of the medium classes. The same thing may be noticed in the case of the frigates.[93] Those of 44, 40, and 28 guns relatively or absolutely diminished in number; whilst the number of the 38-gun, 36-gun, and 32-gun frigates increased. The officers who had personal experience of many campaigns were able to impress on the naval architects of the day the necessity of recognising the sharp distinction that really exists between what we should now call the 'battleship' and what we should now call the 'cruiser.' In the earlier time there were ships which were intermediate between the ship of the line and the frigate. These were the two-deckers of 56, 54, 50, 44, and even 40 guns. They had long been regarded as not 'fit to lie in a line,' and they were never counted in the frigate classes. They seemed to have held a nondescript position, for no one knew exactly how to employ them in war any more than we now know exactly how to employ our armoured cruisers, as to which it is not settled whether they are fit for general actions or should be confined to commerce defending or other cruiser service. The two-deckers just mentioned were looked upon by the date of Trafalgar as forming an unnecessary class of fighting ships. Some were employed, chiefly because they existed, on special service; but they were being replaced by true battleships on one side and true frigates on the other.[94] [Footnote 93: See footnote 92.] [Footnote 94: See footnote 92.] In conclusion, I would venture to say that the strategical and tactical lessons taught by a long series of naval campaigns had been mastered by our navy by the time of the Trafalgar campaign. The effect of those lessons showed itself in our ship-building policy, and has been placed on permanent record in the history of maritime achievement and of the adaptation of material means to belligerent ends. XII THE SUPPLY AND COMMUNICATIONS OF A FLEET[95] [Footnote 95: Written in 1902. (Read at the Hong-Kong United Service Institution.)]