516 SEC. 12. APPLIED MECHANICS. 



the exhibitor in New York, in September 1854, that he considered 

 the " Mary Taylor" the faster vessel of the two, particularly in 

 rough water. Henry Liggins. 



2178do. Half Block Model of the Popovka "Admiral 

 Fopoff." Russian Embassy. 



This ship is the second of the series of circular ironclads in course of 

 construction by Russia. 



The principal dimensions are the following : 



Extreme diameter, 121 ft. Mean draught of water, 13 ft. Height of upper 

 deck at side from load water line amidships, 1 ft. 6 ins. Height of barbette 

 turret from load water line, 13 ft. 3 in. Displacement in tons, 3,550. 



This vessel carries two 41-ton guns, which can be trained completely round 

 inside the turret, their carriages being arranged so as to admit the guns to be 

 lowered down for loading and aiming behind the protection of the thick 

 turret armour, and to be brought up only for firing. 



Besides these heavy guns there are, on each side of the superstructure con- 

 taining cabins and quarters for crew, two smaller guns throwing projectiles of 

 sufficient power to penetrate an unarmoured enemy. 



The vessel and turret are protected by means of armour made in two solid 

 layers, having a total thickness of 1 ft. 6 in. (including equivalent thickness for 

 the hollow iron girders behind armour). Side armour of the vessel extends 

 from the edge of the vessel's upper deck down to 4 ft. 6 in. below load water- 

 line amidships. The upper deck is protected by deck armour 3 in. thick, 

 extending from the circumference of the turret to the circumference of the 

 vessel. 



The propelling power is developed by eight compound vertical engines, 

 each of 80 horse-power (nominal) ; four of these work each an independent 

 screw of 10 ft. 6 in. in diameter, and four remaining engines arranged and 

 worked in pairs propel the middle screws on each side of the vessel. These 

 two screws are made larger and their shafting lowered down so as to increase 

 the speed of the vessel when steaming in deep water. 



This ship, though launched, has not been yet completed for sea, and ac- 

 cordingly no results of her trial with regard to speed have yet been obtained, 

 but it is expected that she will attain from 9 to 10 knots, which for coast 

 defence purposes is considered quite sufficient. 



The vessel is built of iron, with double bottom, and is sheathed with wood 

 and copper. 



The chief principal objects of the design of the Popovka are : 1. The ex- 

 tremely large armour and gun-carrying power attained upon a very limited 

 draught of water. This condition renders such ships extremely valuable for 

 coast defence. 2. Extraordinary steadiness of gun platform, ensuring the 

 efficiency of working the guns at sea, when guns of an ordinary ship must 

 remain silent. 3. Complete protection of hull and battery by uniform thick- 

 ness of armour throughout, which does not exist in any other ironclad. 

 4. Great cheapness of construction as compared with other vessels. 5. Num- 

 ber of compartments around the central vital parts of the vessel which are 

 specially effective for the purpose of saving the vessel in case of torpedo 

 attack. 



2178dp. Half model of Russian Circular Ship of War 



mounted on glass support, showing the position of her large and 

 small guns. The Institute of Naval Architects. 



