HOW TO FILL UP. THE TABLE. THIS Table may be filled up in two ways; viz. Either by drawing the lines from all the points, half-points and quarter-points in the Correct Magnetic Course Column, as in the Example: or from all the points, &c., in the Standard Compass Course Column. The first will be the most useful to the Officers of the Watches in Tactical Manouvres, and has been adopted in the Example. A correct method of drawing these lines is to Project the Deviation Curve on Ryder's Graphic Form (which is supplied with all Chart boxes) and then draw the Straight Lines on this Table, connecting those degrees in each column, lines from which intersect one another at the Curve on the Graphic Form. CORRECT NORTH. THIS table should be filled up from the Deviation Table, page 45, as soon as the ship has been swung, by drawing the lines from all the points, half-points, and quarter-points in the Correct Magnetic Course column, as in the example. By many it will be preferred to that at page 44, especially for deck use in squadrons performing steam evolutions. It shows, at a glance, the Standard Compass Course to be steered corresponding to the Correct Magnetic Course required, and N. by E. vice versa. N.N.E. N.E.byN. EXPLANATION. HOW TO USE THE TABLE. First Case. If the fleet is steering a given course by signal, (which always means a correct magnetic course), and a signal is made to alter course a given number of points to starboard or port, run the finger up or down on the correct Magnetic Course Column the required number of points, and then across on the straight line to the Standard Compass Course Column; and the Standard Compass Course to be steered will be found. Second Case. If the fleet is not steering a correct magnetic course given by signal, but the ships are keeping station, then run the finger across from the Standard Compass Course, which is being steered on the straight line to the opposite column, and proceed as in Case 1. |