XX. The flag officers, or commanders of divisions, are on all occasions to repeat generally, as well as with reference to their respective divisions, the signals from the admiral, that they may be thereby more speedily communicated correspondent to his intentions. And the purpose of all signals for the conduct of particular divisions is then only meant to be carried into execution when the signal has been repeated, or made by the commanders of such particular divisions respectively. In which circumstances they are to be always regarded and complied with by the ships or divisions referred to, in the same manner as if such signals had been made by the admiral commanding in chief. XXI. When ships have been detached to attack the enemy's rear, the headmost ship of such detachment, and the rest in succession, after having ranged up their line as far is judged proper, is then to fall astern; and (the ship that next follows passing between her and the enemy) is to tack or wear as engaged to windward or leeward, and form in the rear of the detachment. XXII. When the fleet is to tack in succession, the ship immediately following the one going in stays should observe to bear up a little, to give her room; and the moment for putting in stays is that when a ship discovers the weather quarter of her second ahead, and which has just tacked before her. On this and every other occasion, when the fleet is in order of battle, it should be the attention of each ship strictly to regulate her motions by those of the one preceding her; a due regard to such a conduct being the only means of maintaining the prescribed distance between the ships, and of preserving a regular order throughout the line. XXIII. As soon as the signal is made to prepare for battle, the fireships are to get their boarding grapnels fixed; and when in presence of an enemy, and that they perceive the fleet is likely to come to action, they are to prime although the signal for that purpose should not have been made; being likewise to signify when they are ready to proceed on service, by putting abroad the appointed signal. They are to place themselves abreast of the ships of the line, and not in the openings between them, the better to be sheltered from the enemy's fire, keeping a watchful eye upon the admiral, so as to be prepared to put themselves in motion the moment their signal is made, which they are to answer as soon as observed. A fireship ordered to proceed on service is to keep a little ahead and to windward of the ship that is to escort her, to be the more ready to bear down on the vessel she is to board, and to board if possible in the fore shrouds. By proceeding in this manner she will not be in the way of preventing the ship appointed to escort her from firing upon the enemy, and will run less risk of being disabled herself; and the ship so appointed and the two other nearest ships are to assist her with their boats manned and armed.