SUBMARINE CABLE 



5604 



SUBMARINE MINE 



borrowed by Jules Verne for Captain Nemo's 

 ship. The Nautilus stayed under water for five 

 hours and blew up an old hulk with a mine; 

 nevertheless, its inventor received no encour- 

 agement and turned his attention to the steam- 

 boat. 



During the War of Secession the Confeder- 

 ates built a submarine known as the David, with 

 which they succeeded in wrecking the Housa- 

 tonic, a Federal ship anchored in Charleston 

 harbor. The David sent six crews to the bot- 

 tom of the sea. It was about sixty feet long 

 and was manned by nine men, eight of whom 

 propelled it by working a screw shaft by hand 

 while the ninth steered. 



In developing the practicable submarine of 

 the present, the American and French nations 

 took the lead. Two early French submarines 

 which proved capable of service were the Gym- 

 note and the Goubet. They were tested at Tou- 

 lon and Cherbourg in 1889, and were maneu- 

 vered with considerable ease. The Goubet had 

 a displacement of two tons. It was equipped 

 with an electric motor and a storage battery; 

 air was furnished from reservoirs, as in the lat- 

 est type. The type of craft which has been 

 developed by the chief nations was the inven- 

 tion of John P. Holland in 1877. It is the 

 Holland vessel that is described in this article. 



The submarine was a most important and the 

 most dreaded factor among the entente allies 

 in the War of the Nations. In the winter of 

 1916-1917 the Germans proclaimed it their chief 

 reliance in the effort to secure victory. The 

 story of this submarine struggle is told in the 

 article WAR OF THE NATIONS. G.B.D. 



No book written prior to 1914 is of value as a 

 description of the submarine of to-day. How- 

 ever, the following are recommended for outlines 

 of the principles of construction and for the his- 

 tory of the craft: Field's Story of the Subma- 

 rine; Bishop's The Story of the Submarine. 



SUBMARINE CABLE. See CABLE, SUBMA- 

 RINE. 



SUBMARINE MINE, an unseen weapon of 

 destruction against which the mightiest battle- 

 ship is helpless, a hidden menace more dreaded 

 by naval men than any gunfire or attack by 

 overwhelming visible forces. Great ingenuity 

 has been used in the preparation of mines 

 which may in an instant turn the most peace- 

 ful harbor or the smoothest seas into a scene 

 of death and disaster. It was not until the War 

 of Secession that submarine mines were re- 

 garded as dangerous, or even practicable; but 

 during that great struggle they acquired such 



a record for destructiveness that it became ap- 

 parent they must play an important part in 

 wars of the future. 



Modern submarine mines are of three kinds 

 observation, electro-contact and automatic. 

 Not only are these mines, when laid, of terrible 

 destructive power, but the placing of them in 

 the sea or inland waters is attended by consid- 

 erable danger. 



Observation Mines. As the name implies, 

 these mines are placed in waters that may be 



SUBMARINE MINES 



They may rest fastened to the sea bottom or 

 may be arranged to float at any distance from 

 the surface. 



overlooked from the shore. They may be ar- 

 ranged singly, in groups, or in line across the 

 openings into harbors. This type of mine has 

 a casing of steel, is buoyant, and is loaded with 

 from 200 to 500 pounds of wet guncotton. It 

 is destructive within a radius of thirty feet 

 when exploded below the surface. Observation 

 mines are exploded from the shore merely by 

 switching on an electric current. A group of 

 three, five or seven mines, or one mine only, 

 may be thus exploded at a .time ; the defended 

 water is plotted out, showing the observer ex- 

 actly the position of ships entering and what 

 mines must be exploded to destroy them. 



