It would he possible, moreover, to fight the guns at the adjacent stern and quarter ports, as indicated by the bearings E i and I i, the lines of fire intersect ing in i, and commanding the sector i u r, whose angle amounts to 24°. It is evident also, that by causing the line of fire I i, to approximate towards II h, suc cessive sectors will be created at every new point of intersection. So likewise the bearings of C c and B b may be changed, and an indefinite number of new points determined, between the limits L 1 and K k. Thus the line of fire C c may be altered into that of L 1, commanding in conjunction with the bearing II b, the sector / y r, whose angle amounts to 53°. Or the direction II b may be transformed into any other as K /•, intersecting the bearing C c when both are pro duced.
Any force therefore that may be employed in at tacking a ship with a curvilineal stern, will meet with a resistance of a much more formidable kind, than if its energies were expended on a square stern. If we compare, for example, the after broadside ports of a ship of each kind, we shall observe that, in the old form, the insulated fire or a single gun is all the effect that can be produced; whereas in the curvilineal stern, the gun at the quarter port can lend the most effectual aid; and by causing different discharges to converge to the same point, dispense a terrible and destructive cross fire over a very considerable range. And this contrast is increased in a still more remarkable degree, when we compare the conditions of the quarters; since in the new stern, the means of defence, for the same space, are quite equal to those of any other part of the ship, but in the square form vanish altogether. In like mant.er, if the attacking force were situated di rectly astern, a much More effectual defence could be created, by means of the former, than could possibly be afforded by the latter, from the great facility it af fords in working the guns, and the assistance that may in some eases be obtained from the quarters.
'knee it appears, that even in a greater arc 1/tan semicircle, may poin:s of cross fire be produced about the curvilineal stern: there(' y throwing around this im portant part of a ship the energies of a formidable and pelf eet defence, and produced by means at once practica ble and secure; leaving no point of impunity open to an acute and enterprising enemy, as in the case of the square stern, or any abrupt transition from a well-defended part, to one feeble and insecure.
As a more particular reference may be necessary to the positions of the points of cross fire, the following table has been prepared. The first column indicates the lines of fire which intersect each other; the second column contains the magnitudes of the ordinates re presenting the distances of the points of cross fire from the principal axis XV; and the third the distance of the ordinates estimated on the principal axis from the common point of origin K. To refer for exam ple the point of intersection produced by the lines of cross fire B b and C c to the axis XV, it will be found that the ordinate n G = 18.2 feet, and the ordinate GE = 6.2 feet. So also for the point of intersection of Bb and Li, we have the ordinate /L = 19.5 feet, and LK 8.0 feet.
The danger of fire, from the explosions of the guns taking place, within board, has been briefly alluded to; but as the superiority of the curvilineal stern, in this point of view, is strikingly conspicuous, it may not be improper to allude to this part of the subject more particularly.
By comparing Figs. 6. and 7. Plate CCCCXCVII. it will be perceived that, in the old form (Fig. 6.) the muzzle is twenty-one inches within the rail, whereas, in the new form, (Fig. 7.) the muzzle is eighteen inches beyond the frame of stern; the guns of each be ing supposed in a fore and aft direction. It is scarce ly necessary to insist on the superiority of the latter form above the former, in relation to this very impor tant consideration; since an explosion can never take place within board, without obvious disadvantages and danger. When the guns are trained, the evil will be increased in the square stern; whereas, with the great est possible angle the case will admit in the curvi lineal stern, the muzzle is never within the stern frame. These disadvantages in the square stern arise from the over-hanging form of that Dart of the ship, and from the inconvenient distribution of the timbers of the frame.
With respect to the guns of the after broadside ports of the two frigates, it may be observed, that they are under precisely the same circumstances, their muz zles in both cases being beyond the side of the ship, and also in the same degree. A fore and aft view is given in Fig. 8. Plate CCCCXCVII.