198 KXPERIMENTAL CRUISi: Or THE 



gone iu coiipequenee of one of ibe combatants having his fire s-topped by the sea, • 

 Avhile the othtr was able to contiuue it by reason of the height of his batteries 

 above the water. 



The roll of a vessel plays an impoi tant part in this question, but before speak- 

 ing of it, let me first say a word of the pitching (that is, of the oscillations in 

 direction of the ship's length), because it is a point on which I thinlc, at the pre- 

 sent day, all are agreed. The pitching of the iron elads, is, by iiniversul testimony 

 mild and easy beyond comparison. They have proved that they can keep their 

 head up against the heaviest sea without falling off, even at a low speed, and can 

 go before the wind without shipping seas over the stern, notwithstanding the sharp- 

 ness of their build, and in both cases their roll is extraordinarily moderate. This was 

 found to be the ease for all of them under all circumstances of weather, wind, and 

 sea. It is to these characteristic qualities they owe the comparative immunity 

 with which they encountered the gale of October 1st, while the Napoleon had her 

 bows stove in, and the Talisman labored heavily, shipped water over stern and 

 bows, and experienced damage enough to send her to dock. Tiiis point may then 

 be held settled. 



The subject of the " roll," that is, the motion of the vessel transversely from 

 side to side, has been much already and will doubtless yet be more discussed, 

 but the present facts prove that the ironclads need not fear comparison on 

 this head. Neither during the gale, nor during the fine weather that succeeded, 

 did they roll' more than the others; the transversal oscillations were not more 

 in number, or larger in extent for them than the others. In fact, the prob- 

 lem is apparently altogether independent of the armour. For many reasons I 

 consider it does not devolve on me to form a complete theory of the roll, its 

 causes and effects ; but one in particular would be sufficient to stop me from 

 attempting it, which is, that the most competent men of the present day seem 

 to be much divided on the subject. Our predecessors had only to deal with 

 sailing vessels, and did not find themselves called upon to study this question 

 deeply; it has become really of great importance only to steamers which have to 

 keep their course independent of the direction of the wind and current, and of the 

 state of sea and weather, or rather, to put it more strongly, have almost always 

 to make headway in contradiction more or less complete to these elements. The 

 reason why the modern ship is subject to a roll greater than the ancient, is th^t 

 it is a steamer, having its propelling power within itself, and not that it is clad 

 in armour. This is the first point that results from the trials we are speaking 

 of. 



Since then the question of the roll has acquired real importance, only within a 

 short time back, it is not wonderful that the persons who have studied it should 

 be, notwithstanding their merits, yet disagreed on the subject. With the public 

 generally, and even with sailors, the belief is still firmly held that the number of 

 rolls is determined by the more or less rapid succession of waves that lift the 

 ve?sel, and that the magnitude of the roll is inversely proportional to the " sta- 

 bility " of the vessel. This is in fact the theory which would first naturally occur 

 to the mind ; but we now find some eminent men proclaiming that this theory is 

 altogether false, and they draw from the results obtained during this cruise of the 



