Curvilineal Stems of Ships. 209 



being defended ; and hence a point of impuniii/ is created, from 

 the impossibility of crossing the lines off re, which proceed from 

 the after broadside-gun, and either of the stern-guns. 

 Secondly, — That to defend even an arc of 47°, right aft, produces 

 7mich inconvenience, and a considerable waste of time, from the 

 difficulty of obtaining the requisite positions for the guns, in con- 

 sequence of the rudder-head, and the projecting timbers of the 

 stern. 

 Thirdly,— That in defending the before-mentioned arc, the dangers 

 of fire are very considerable, from the muzzles of the guns being 

 so very much within the whole of the stern-frame. 

 Fourthly. — That only one point of cross-fire can be found, at the 



same time, in any part surrounding the square stern. 

 Such are the limits which are therefore prescribed to the de- 

 fence of the square stern, from its peculiarly disadvantageous 

 form; the difficulties and disadvantages of which can only be 

 surmounted by the general and efficient* application of the curvi- 

 lineal stern. 



The preceding conclusions having been obtained for the square 

 stern, we shall in the next place proceed to the consideration of the 

 experimental results obtained for the curvilineal stern ti. 



* I employ Ihe term efficient, because attempts have been made to accom- 

 modate the new form to the old ; to retain the appearance of the latter, and 

 to obtain, if possible, the advantages of ihe former ; — points very desirable 

 to be obtained unquestionably, but which require great skill and consideration 

 for their determination ; — since it is possible that, in order to gratify the eye, 

 which has lieen educated to admire a particular form as the most beautiful, 

 the soundest maxims of mechanical knowledge may be sacrificed, and also 

 the most important principles of defence. The history of science proves 

 the accommodation of theories to be next to useless. Nature has but one 

 mode of working, and that can never be obtained by the union of erroneous 

 principles with truth. 



+ All the bearings hereafter mentioned, were determined with the ports in 

 their ordinary state; no linings liaving been stripped from them to increase 

 their width, as was done in the experiments on board the Koadicea. It was 

 considered unnecessary in the case of the Hamadryad, because the very supe- 

 rior means of defiance afforded by her curvilineal stern, could be most strik- 

 ingly displayed without removing them. As remarked, however, in a preced- 

 ing iiuge, this difleiencc in the mode of conducliiig the cxpevinieuls, gavo 



