Down to the end of the War of the Austrian Succession—­a period which is usually deemed to be one of conspicuous depression in the naval art—­the classification of our larger sailing vessels was purely arbitrary.  The “Rates” (which had been introduced during the Dutch wars) bore no relation to any philosophical conception of the complex duties of a fleet.  In the first rate were 100-gun ships; in the second, 90-gun ships—­all three-deckers.  So far the system of rating was sound enough, but when we come to the third rate we find it includes 80-gun ships, which were also of three decks, while the bulk of the rest were 70-gun two-deckers.  The fourth rate was also composed of two-decked ships—­weak battle-units of 60 and 50 guns—­and this was far the largest class.  All these four rates were classed as ships-of-the-line.  Below them came the fifth rates, which, though they were used as cruisers, had no distinct class name.  They differed indeed only in degree from the ship-of-the-line, being all cramped two-deckers of 44 and 40 guns, and they must be regarded, in so far as they expressed any logical idea of naval warfare, as the forerunners of the “Intermediate” class, represented in the succeeding epochs by 50-gun ships, and in our own time by armoured cruisers.  The only true cruiser is found in the sixth rate, which comprised small and weakly armed 20-gun ships, and between them and the “Forties” there was nothing.  Below them, but again without any clear differentiation, came the unrated sloops representing the flotilla.

In such a system of rating there is no logical distinction either between large and small battleships or between battleships and cruisers, or between cruisers and flotilla.  The only marked break in the gradual descent is that between the 40-gun two-deckers and the 20-gun cruisers.  As these latter vessels as well as the sloops used sweeps for auxiliary propulsion, we are forced to conclude that the only basis of the classification was that adopted by Henry the Eighth, which, sound as it was in his time, had long ceased to have any real relation to the actuality of naval war.

It was not till Anson’s memorable administration that a scientific system of rating was re-established and the fleet at last assumed the logical constitution which it retained up to our own time.  In the first two rates appear the fleet flagship class, three-deckers of 100 and 90 guns respectively.  All smaller three-deckers are eliminated.  In the next two rates we have the rank and file of the battle-line, two-deckers of increased size-namely, seventy-fours in the third rate, and sixty-fours in the fourth.  Here, however, is a slight break in the perfection of the system, for the fourth rate also included 50-gun ships of two decks, which, during the progress of the Seven Years’ War, ceased to be regarded as ships-of-the-line.  War experience was eliminating small battleships, and therewith it called for a type intermediate between battleships and cruisers, with whose functions we shall have to deal directly.  In practice these units soon formed a rate by themselves, into which, by the same tendency, 60-gun ships were destined to sink half a century later.