92 ANNUAL OF SCIENTIFIC DISCOVERY. 



3,480 tons, and than the Warrior, of 6,000 tons; and yet the Iron- 

 sides and the Warrior have only the middle portion of their hulls 

 plated, their ends being merely of wood without armor. The guns 

 of the monitors near the center of motion are supported upon the 

 keel and kelsons, upborne by the depth of water under them, and 

 carried by the whole strength of the hull. In monitors, heavier guns 

 are therefore practicable than ever can be carried in broadside out upon 

 the ribs of a ship. In the monitors, concentration of guns and armor is 

 the object sought. In them the plating is compressed into inches of 

 elevation ; while in the ironsides class it is extended over feet ; and the 

 comparatively numerous guns distributed over the decks of the iron- 

 sides class are molded in a few larger ones in the turrets of the moni- 

 tors. When tlie power is required in the individual guns, enough to 

 crush and pierce the side of an adverary at a single blow, the most for- 

 midable artillery must be employed ; and 15-inch guns are the most 

 formidable, which, so far, we have tried ; but no vessels of the iron- 

 sides class can carry these guns ; and the monitors actually do carry 

 them. 



If target experiments are reliable, a shot from the 15-inch gun will 

 crush in the sides of any vessel of the ironsides class in Europe or 

 America. A single well-planted blow would sink either the Warrior, 

 Gloire, Magenta, Minotaur, or Bellerophon. The Dictator, of 3,000 

 tons, has armor thick enough, I believe, to withstand 15-inch guns. 



The objection to the monitor class, such as I have seen in use, are 

 from fewness of guns, the lack of rapidity in fire in battering forts, or 

 wooden vessels ; the loss of accommodation from dispensing with the 

 upper deck, or decks ; the greater unhealthiness from dampness, and 

 from confinement below in even a moderate sea; from the loss of liijht, 



^ O 



and from depending upon blowers driven by steam for ventilation. 



The monitors are slower than their steam power would seem to 

 promise. In all of them the slip of their screws is excessive. This 

 I attribute to the overhang, which if a source of strength in action, 

 from its use as a ram, and from its protecting the propeller and rud- 

 der, is a source of weakness anil strain at sea. The overhang has the 

 advantage of keeping the vessel -very steady ; she can not roll with 

 these wing-like projections holding up her sides, nor pitch, nor send 

 with the immense Hat surface of the overhang to resist those motions ; 

 but as the monitor is slower than other vessels of like tonnage and 

 power, it must be presumed the difference of shape makes the differ- 

 ence of speed ; and the overhang constitutes the sole difference of 

 shape. 



If ordinary vessels can endure the pitching and sending motions, 

 it may be inferred that the monitors can endure them. If ordinary 

 vessels can h.ive their rams below water, so may the monitors; nor 

 is it necessary to equality, that the rudder and propeller of the mon- 

 itor should be letter protected than those of our competitors. 



The monitor model rolls very little, and is extremely easy in a sea 

 w:tv. In a gale of wind, it was f>n:id on board the monitor Wee- 

 lt frL-rn, that while her companion, wooden corvette Iroquois (deemed 

 a very perfect model), had an excessively violent motion, so violent, 

 indeed, that no one could st:ui:l u;>o:i her decks without the assistance 

 of life lines , the Weekawken had so little motion that a bottle of 



