So far as we can judge, the current view at this time was that where fleets were equal, every known form of concentration was unadvisable upon an unshaken enemy.  The methods of the Duke of York’s school were regarded as having failed, and the result appears to have been to convince tacticians that with the means at their disposal a strict preservation of the line gave a sure advantage against an enemy who attempted an attack by concentration.  Tactics, in fact, in accordance with a sound and inevitable law, having tended to become too recklessly offensive, were exhibiting a reaction to the defensive.  If the enemy had succeeded in forming his line, it had come to be regarded as too hazardous to attempt to divide his fleet unless you had first forced a gap by driving ships out of the line.  This idea we see reflected in the 6th paragraph of the Duke of York’s twenty-second article (1673) and in Russell’s new twenty-third article, enjoining ships to close up any gap that may have been caused by the next ahead or astern having been forced out of the line.  Briefly stated, it may be said that the preoccupation of naval tactics was now not so much to break the enemy’s line, as to prevent your own being broken.

But the matter did not end here.  It was seen that when your own fleet was superior, concentration was still practicable in various ways, and particularly by doubling.  Tacticians were now mainly absorbed in working out this form of attack and the methods of meeting it, and Russell’s elaborate articles for handling squadrons and subdivisions independently may well have had this intention.

The new phase of tactical opinion is that which we find expounded in Pere Hoste’s famous work, L’ Art des armees navales, ou Traite des evolutions navales, published in 1697 at the instigation of the Comte de Tourville.  The author was a Jesuit, but claims that he is merely giving the result of his experience while serving with the great French admirals of that time, who had learned all they knew either as allies or enemies of the English.  ’For twelve years,’ he says in his apology for touching naval subjects, ’I have had the honour of serving with Monsieur le Marechal d’Estrees, Monsieur le Duc de Mortemart, and Monsieur le Marechal de Tourville in all the expeditions they made in command of naval fleets; and Monsieur le Marechal de Tourville has been kind enough to communicate to me his lights, bidding me write on a matter which I think has never before been the subject of a treatise.’

The whole system of tactics that he develops is based, like Russell’s, on the single line ahead and the independent action of squadrons.  The passages in which he elaborates the central battle idea of concentration by doubling are as follows:  ’The fleet which is the more numerous will try to extend on the enemy in such a manner as to leave its rearmost ships astern, which will immediately turn [se repliera] upon the enemy to double him, and put him between two