Curvilineal Sterns of Ships. 203 



also to afford room for an ample recoil, excepting in one position 

 in the square stern, where the space behind the gun was somewhat 

 confined, in order to obtain an increased amplitude in the bearing; 

 but which case will be referred to, in the order in which it occurs. 



The moment the position of a gun was finally determined, its 

 bearing was carefully laid down on the deck, and referred to a 

 longitudinal line, passing through the middle section of the ship. 

 And in order to give every possible advantage to the square stern, 

 the ports of the Boadicea submitted to experiment, were entirely 

 stripped of their linings, so as to present only the naked timbers ; 

 whereas in the ship with the curvilineal stern, the linings were in 

 every case preserved, and which therefore gave to the square form, 

 a very considerable advantage during the comparison ; but even 

 with this advantage, it will be found, that the means of defence 

 it afforded were decidedly inferior to those presented by the 

 curvilineal form. 



For the purpose of comparing the different bearings of the guns, 

 determined in the course of the experiments, on board the two 

 frigates, two points K,K, figs. 1 and 2, plate III, were assumed in the 

 longitudinal axis X Y of the vessels, at the distance of 17 feet 

 from the after part of the counter of the square stern, and also 

 from the after part of the lower stool of the curvilineal stern. 

 From these points as centres, and with radii of 27 feet, two 

 arcs of circles a b c c b a, a b effe b a were described, the former 

 surrounding the square stern, and the latter that of the curvilineal 

 form. To these circumferences, the various arcs or ranges swept 

 over by the guns, in their transition from one bearing to another, 

 were in all cases referred. 



The first experiments performed, were on board the Boadicea, or 

 square-stern vessel. An eighteen pounder was placed at the after 

 broadside-port, and trained to its greatest possible angle before 

 the beam, as denoted by the lines A a, fig. 1, plate III, or fig, 1, 

 plate IV ; forming in the first-mentioned figure, an angle a AY 

 of 61°, with the principal longitudinal axes X Y of the vessel ; the 

 outer extremity of the muzzle of the gun, being at the same time 

 within the external edge of the port four inches. This bearing 



P 2 



