SUBMARINE VESSELS 



In diving, the Holland type of boat takes in suffi- 

 cient water ballast to lower it to the surface of the 

 water. The horizontal rudders are then brought into 

 use causing it to descend to the desired depth, and 

 keeping it at an approximately uniform distance from 

 the surface while running submerged. By this arrange- 

 ment the boat can dive very quickly, requiring only a 

 matter of eight or ten seconds for reaching a depth of 

 thirty feet. Record plunges have been made in less 

 time than this. 



The armament of the Holland boat was originally 

 designed to consist of three tubes, two of which were 

 for throwing aerial torpedoes and shells, and the third 

 for discharging Whitehead torpedoes. One of these 

 aerial guns was placed in the bow, and one in the 

 stem; but later the stem tube was abandoned. The 

 bow gun was designed to discharge projectiles a dis- 

 tance of about one mile, such projectiles weighing 

 something over two hundred pounds and carrying one 

 hundred pounds of gun-cotton. The tube for dis- 

 charging the Whitehead torpedo was practically the 

 same as the submerged tubes in use at present on 

 battle-ships. 



Although this Holland is now the type of diving boat 

 most familiar to the majority of people, and the one 

 in use in several navies, it should not be understood 

 that the Holland boats were the only successful sub- 

 marines constructed up to this time. France and Rus- 

 sia had produced successful diving boats; and in 

 America those invented by Simon Lake, some of which 

 are used for wrecking and salvage work as well as for 



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