204 Mr. Harvey oji Square a?nl 



having been determined, the gun was next brought into the position 

 denoted by the line B b, fig. 1, plate III *, being the greatest possi- 

 ble angle at which it could be trained, abaft the beam; the line 

 of fire forming with the principal axes of the vessel, the angle 6 BX 

 of 35J°. The arc a b, intercepted between the two bearings, 

 amounted to 46°; and hence it follows, that an object placed in 

 any part of it could be hid by a shot from the after broadside-port, 

 confined of course to the limits prescribed, by the ordinary charge 

 of powder. The circular dots introduced in the arc a b, as also in 

 all the arcs which may hereafter be alluded to, are designed to 

 indicate, that every part of the space contained between the extreme 

 bearings can be defended. 



The exact position of the point b having been determined by the 

 last experiment, the gun was next removed to the adjacent port 

 in the stern, and trained to its greatest possible angle, as denoted 

 by the line Cc t fig- 1 > plate III, or fig. 2, plate IV, and forming with 

 the axis X Y, the angle c C X of 32|°. To obtain this bearing, the 

 muzzle of the gun was brought four feet within the forepart of the 

 rail, creating thereby great danger from fire. It will also be ob- 

 served, by referring to the former figure, that the truck of the gun 

 was brought into contact with the rudder-head ; so that the utmost 

 bearing was determined. 



This being the greatest bearing that could be obtained with a 

 stern gun, directed towards the adjacent quarter of the ship, neces- 

 sarily left the arc b c Fig. 1 , plate I, amounting to 32 3°, entirely 

 undefended; and it was also remarked, that the bearings B b and 

 C c, were not in directions parallel to each other, but in a state of 

 divergency, amounting to three degrees ; and that therefore the 

 extreme lines of fire proceeding from the after broadside-port, and 

 the adjacent port in the stern, could not under the present circum- 



* A similar bearing is represented inB b, Fig. 1, Plate IV., with the gun deli- 

 neated ; it not being possible to introduce both bearings at the same port, at 

 the same time. 



t It would appear from the diagrams, tliat the line of fire C c, would carry 

 away the angles of the stern-ports. This, however, cannot be the case, since 

 the part which it apparently crosses is above the line of fire. 



