Popular Scicucc Monthly 



683 



Two Mines Which Make Marine 

 Warfare More Terrible 



THE accompanying illustrations show- 

 two ditTercnt types of mines whicii 

 have been devised since the great war 

 started. The mine with the periscop;' 

 attached is said to be the latest Teuton 

 lure for British skippers who are seeking 

 the $2,500 reward offered by the British 

 Admiralty for ramming a submarine. 

 Not long ago one of these periscope 

 mines was sighted in the English channel 

 by a steamship captain. Taking it lor 

 the periscope of a submarine the captain 

 ordered all speed ahead, in an attempt 

 to ram what he thought to be a lurking 

 U-boat. As he was fast approaching it 

 he noticed, to his bewilderment, that it 

 did not move. He became suspicious 

 and when almost upon the periscope, 

 ordered his pilot to give it wide berth. 

 Later he in\'esti- 

 gated cautiously 

 and found that the 

 periscope was at- 

 tached to a huge 

 mine. 



The other mine is 

 the invention of 

 Giovanni Elia, of 

 Paris, who believes 

 that it is the most 

 effective of any 

 mine now in use. 

 His mine cannot 

 explode by coming 

 in contact with strong tides or 

 striking slight obstructions in 

 the water. 



It is anchored, and, when a 

 moving ship comes in contact 

 with it, a shock is produccc 

 which is absorbed entirely by 

 the circular frame projecting 

 from the body of the mine. 

 Under the influence of this 

 shock three screws in the firing mechan- 

 ism are cut through. 



In the meantime the mine, having 

 come in contact with the vessel, turns, 

 under the effect of the friction of the hull 

 of the ship. This turning movement 

 cocks a striker and then releases it, 

 causing the expjosion. The mine can be 

 manipulated and transported without 

 danger prior to its being submerged. 



Above: The peri- 

 scope mine — the 

 Teuton lure for 

 British skippers. 

 The periscope is 

 merely attached 

 to the top of an 

 anchored mine. 

 At left: A mine 

 which cannot ex- 

 plode unless 

 struck by the hull 

 of a ship. The 

 circular frame is 

 a shock absorber 



The Deepest Known Place 

 in the Ocean 



THE greatest ocean depth known is 

 5,269 fathoms, or 31,614 feet. It is 

 about seventy-five miles southeast of the 

 Island of Guam. This figure was ob- 

 tained in 1899 by the U.S.S. Nero when 

 running a line of soundings to locate the 

 Honolulu-Manila cable. The mean 

 depth of the entire ocean is about 2,100 

 fathoms, or 12,600 feet. 



