with motion a-head, as required for good steerage, each ship having sufficient to keep her under command of the rudder, and let it consist of twelve ships occupying a space of two miles, as extended in line of battle,at one cable's length asunder*; and F’s motion through the water, if at the rate of four miles per hour, may be expressed by the space comprehended by the perpendicular lines marked by F and G on the scale below. These four lines comprehended by F and G will also express the time in which any fleet, B, may perform his course, when coming down to the attack from the windward. 26. Let B be the opponent fleet, consisting also of twelve ships, and four miles to windward; and let the point A be 440 yards, or one quarter of a mile right to windward of the point G. The length of a ship of 74 guns is about Interval between two ships at one cable's length 54 yards asunder 240 The sixth part of a mile 294 6 Six ships, formed in a line of battle a-head, will asunder, may form another scale sufficiently 27. Then B, by putting before the wind, if he shall arrive at the point A, in the same time that F, the fleet to leeward, has arrived at the point G, his motion will have been at the rate of 5 miles per hour, as must be evident from the scale of miles placed at the top of the figure; and his course, as described by the lines BA and C D, will be slanting or diagonal, forming an angle of 43 degrees with B C, his line a-head, and nearly 4 points large from the wind. 28. Again, if F, (Plate V. Fig. 2.), by carrying more sail, shall move at the rate of six miles per hour, that is, from F to G; then B, having his course made thereby the more slanting, will have just so much the greater difficulty of keeping his ships in line a-breast while coming down to the attack. For the leading ship meeting with no obstruction in her course, will push on, whereas every accident of obstruction accumulating, as it happens to each ship progressively, the rear, being affected in the greatest degree, will, for that reason, be left the farther a-stern. But, from the very form of this slanting course, every ship a-stern will be apt to get into the wake of the ship a-head. Therefore, the whole fleet of B, van and rear, will not arrive in the same time at the line A D, so as to be in a perfect line a-breast, and parallel with the fleet to leeward, but will have assumed the lask ing form, as represented at the points M, N, and O, in the different parts of the course. 29. And again (in Plate V. Fig. 3.), if the fleet to leeward shall keep his wind, so as to lie up one point, as per line of course F G, making an angle of 114 degrees with his former line of course KFK: Then the rears of the two fleets will thereby be removed at a much greater distance, and the van A, of consequence, must be sooner up with the enemy's van, and evidently so much the farther from support, while F, by bringing up his ships in succession, will have it in his power to disable the van A, (No. 21.) and will afterwards bear away as at H, unhurt, and at pleasure; while B, at this time, by the supposition, being crippled, or having his rear, D, obstructed, and at a distance, will be unable to prevent him. And, in all the three cases, it is evident that the fleet B, so soon as he shall approach within reach of gun-shot, must be exposed to the fire of F's whole line, for he will be a-breast of B continually in every part of his course. 30. But the difficulty of bringing the rear of the windward fleet to action will still be more increased, if the sternmost ships of the fleet to leeward, in place of keeping their wind, shall bear away occasionally, as at M L, (Fig. 3.) 31. All which being admitted, the difficulty of bringing opponent fleets to close engagement may |