In this discussion the writer has in view the leading feature which, while aiding the action of the fire-ship, also gives this war of 1665 its peculiar interest in the history of naval tactics. In it is found for the first time the close-hauled line-of-battle undeniably adopted as the fighting order of the fleets. It is plain enough that when those fleets numbered, as they often did, from eighty to a hundred ships, such lines would be very imperfectly formed in every essential, both of line and interval; but the general aim is evident, amid whatever imperfections of execution. The credit for this development is generally given to the Duke of York, afterward James II.; but the question to whom the improvement is due is of little importance to sea-officers of the present day when compared with the instructive fact that so long a time elapsed between the appearance of the large sailing-ship, with its broadside battery, and the systematic adoption of the order which was best adapted to develop the full power of the fleet for mutual support. To us, having the elements of the problem in our hands, together with the result finally reached, that result seems simple enough, almost self-evident. Why did it take so long for the capable men of that day to reach it? The reason--and herein lies the lesson for the officer of to-day--was doubtless the same that leaves the order of battle so uncertain now; namely, that the necessity of war did not force men to make up their minds, until the Dutch at last met in the English their equals on the sea. The sequence of ideas which resulted in the line-of-battle is clear and logical. Though familiar enough to seamen, it will be here stated in the words of the writer last quoted, because they have a neatness and precision entirely French:--