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3d Method.

FIG. 18.

24

Commander-in-chief signals:

From the right of fleet, form column of vessels-fleet E-right vessel* N.

Flag-ship of van division: Division E-right vessel N.

Flag-ships of centre and rear divisions signal: Division E.

Upon the hauling down of these signals, the vessel on the right of the fleet keeps its course; the other vessels steer E.; two resuming its original direction, when in the wake of one; three when in the wake of two, and so on to the last vessel.

It is evident that the fleet can be formed into column, from the left, preserving the original direction, according to the same principles.

When the commander-in-chief desires to leave it optional with the divisional commanders to

*Speed signals should always be made by the divisional commanders to their divisions.

come into column either by obliquing or taking the two sides of the triangle, he omits signalling the course to the fleet thus:

From the right of fleet, form column of vesselsright vessel N.*

NOTE TO 1ST METHOD (FIG. 16).—In close order, the distance between the right and left vessels of a fleet of twentyfour vessels, in line, is 2,760 fathoms; it follows, then, that the left vessel steering N.E., and thus making an angle of 45° with the course, will traverse 3,903 fathoms and strike the perpendicular to the line described by the right vessel, moving N., at a distance of 2,760 fathoms from A, the point of departure of that vessel when, if both vessels have proceeded at the same rate of speed, the distance between the van and the rear will be but 1,143 fathoms, whereas it should be 2,760 fathoms (see Table A), to insure which distance the right vessel should have made 5,520 fathoms. Now 5,520: 3,903 :: 10: 7.07-therefore the speed of the left vessel should be but 7ths of that of the right. Again, the second vessel, 120 fathoms from the first, will traverse 169.7 fathoms, and strike the perpendicular at a distance of 120 fathoms from A, when the first vessel should be 120 fathoms ahead of her, and have made 240 fathoms. But 240: 169.7 :: 10: 7.07-therefore, the speed of the second vessel must also beths of that of the right vessel; and so with the other vessels, each one resuming her speed when she comes N., in the wake of the leading or guide vessel.

This seems self-evident, and yet an eminent French tac

* This paragraph applies to the succeeding problems also.

tician, in forming column in this way, directs the leader of the column to "slow" thus:

"Lorsque l'evolution est dessinée, la tete de la ligne diminue de vitesse pour accélérer le mouvement des vaisseaux de queue.”—("Tactiqe supplémentaire a l'usage d'une Flotte Cuirassée." By Vice-Amiral Cte. BOUËT-WILLAUMEZ, Commandant-en-Chef l'escadre d'evolutions. )-Evolution

No. 5.

The annexed table shows the rate of speed for each point of obliquity from the course, supposing the speed of the leader (or leaders, since it is evident that the same reasoning applies whatever may be the front of the column; a double column, for instance, being simply two "columns;" a triple column being three "columns of vessels," etc.) of the column to be ten knots an hour, from which every captain-the speed of the leader of the column being knowncan readily deduce that of his own vessel. For instance, let the line, heading N. and steaming 15 knots an hour, be ordered to form column, from the right, preserving the original direction, and the course signalled by the divisional commanders to the obliquing vessels be N.N.E. Then 10: 15: 7.6: 11.4; and we have for the obliquing vessels 11 knots and an hour.

[blocks in formation]

When the commander-in-chief desires to form the column in the shortest possible time, without regard to the positions of the vessels in it, he has but to make general signal full speed. It will sometimes happen, however, that vessels coming into column thus will interfere with each other, when the junior officer must slow down until his superior has passed him.

With a fleet of more than twelve vessels, the angle formed by the course of the obliquing vessels with that of the leader of the column, should be at least two points, since if it be less the fleet will be too long in forming. For instance, twenty-four vessels in line, in close order*, heading N., will be three hours in forming 'column of vessels," steering N. by E., if the angle of obliquity be but a half point, fifty-six minutes if it be two points, thirty-two minutes if it be four, and twenty-three minutes if it be six points. I think four points should be preferred when practicable, especially in the presence of an enemy, since the vessels while forming would be in direct echelon, and, by "slo wing," the wing nearest the forming column could be thrown into double echelon, thus making, with the vessels already in column, the three sides of a square impossible to penetrate.

*As the arcs described by the different vessels in coming to the oblique course will not be exactly the same, this is not mathematically correct, but it will be found practically so, provided the vessels continue at full speed until on the oblique course.

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