’III.  Others prefer to give as a general rule, that the flag officers of the less numerous fleet attack the flag officers of the enemy’s fleet;[4] for by this means several of the enemy’s ships remain useless in the intervals, and the enemy cannot double you.

’IV.  Others prefer that the three squadrons of the less numerous fleet each attack a squadron of the more numerous fleet, taking care that each squadron ranges up to the enemy in such a manner as not to leave any of his ships astern, but rather leaving several vessels ahead.

’V.  Finally, there are those who would have the less numerous fleet put so great an interval between the ships as to equalise their line with that of the enemy.  But this last method is, without doubt, the least good, because it permits the enemy to employ the whole of its strength against the less numerous fleet.  I agree, however, that this method might be preferred to others in certain circumstances; as when the enemy’s ships are considerably less powerful than those of the less numerous fleet.’

Having thus explained the system of doubling, he proceeds to give the latest ideas of his chief on breaking the enemy’s line, or, as it was then called, passing through his fleet.  ‘We find,’ he says, ’that in the relations of the fights in the Channel between the English and the Dutch that their fleets passed through one another....  In this manner the two fleets passed through one another several times, which exposed them to be cut off, taken, and mutually to lose several ships. Remark.—­This manoeuvre is as bold as it is delicate, and consummate technical skill is necessary for it to succeed as happily as it did with the Comte d’Estrees ... in the battle of the Texel, in the year 1673, for he passed through the Zealand squadron, weathered it, broke it up, and put the enemy into so great a disorder that it settled the victory which was still in the balance.’[5]

After pointing out by diagrams various methods of parrying the manoeuvre, he proceeds:  ’I do not see, then, that we need greatly fear the enemy’s passing through us; and I do not even think that this manoeuvre ought ever to be performed except under one of the three following conditions:  (1) If you are compelled to do it in order to avoid a greater evil; (2) If the enemy by leaving a great gap in the midst of his squadrons renders a part of his fleet useless; (3) If several of his ships are disabled....

’Sometimes you are compelled to pass through the enemy’s fleet to rescue ships that the enemy has cut off, and in this case you must risk something, but you should observe several precautions:  (1) You should close up to the utmost; (2) You should carry a press of sail without troubling to fight in passing through the enemy; (3) The ships that have passed ought to tack the moment they can to prevent the enemy standing off on the same tack as the fleet that passes through them.’