THE NATIONAL, GEOGRAPHIC MAGAZINE 



285 



sea and shore, and you will begin to see 

 that, even with all its blessings of safe 

 harbors, land-locked bays, and havens of 

 refuge, the continental shelf is not with- 

 out disadvantages to mankind. 



After peace comes again to bless man- 

 kind, and the nations, freed from the 

 menace of war, are able to devote all their 

 remarkable energies to trade, one of the 

 first phases of oceanography that will 

 command wide attention will be the shal- 

 low-water system fringing the continents. 

 It took seventy million dead-weight tons 

 of ocean shipping to carry the commerce 

 of the world before the present war. 

 That it will take vastly more to carry the 

 water-bound trade of the years that fol- 

 low is patent to all who have studied the 

 situation. 



The war has taught the world in thun- 

 der tones the interdependence of peoples 

 and the interrelation of nations, and at 

 the same time it has shown how much 

 more mankind can accomplish when it is 

 doing its utmost than when it lives as in 

 the easy-go-lucky days of other years. 

 And nations hereafter will not be content 

 with the slow methods of the past. 



HOW THE SUBMARINE MAY SERVE 

 HUMANITY 



With more ships afloat than there were 

 before the heartless Hun ran amuck with 

 the submarine, there will be a greater de- 

 mand for minute surveys of all shallow 

 water in coastal territory — thousands of 

 square miles will need even the intensive 

 method of the wire drag, which does not 

 trust to soundings to reveal pinnacle 

 rocks, but touches every square inch of 

 the water at the appointed depth, and 

 thus makes sure that nowhere is there an 

 obstruction reaching above it. 



It is probable that the submarine, an 

 American invention prostituted to foul 

 use by the Hun, will be rescued from its 

 ignoble use and made to serve humanity 

 where now it outrages civilization. Able 

 now to descend to the bottom hundreds 

 of feet below the surface, it is not im- 

 probable that before many years have 

 passed submarine expeditions will take 

 the place of polar expeditions and many 

 mysteries of the sea will be solved. 



One of the pressing problems of the 

 -after-the-war period will be that of the 



derelict. Among the millions of tons of 

 shipping destroyed by the submarine, it 

 is too much to hope that every ship tor- 

 pedoed beyond the redemption of the 

 salvage forces now lies harmless at the 

 bottom of the ocean. That some of them 

 are drifting derelicts, adding their menace 

 to navigation, is certain. 



STRANGE STORIES OE DEREUCTS 



How hard it sometimes is to send a 

 ship to the bottom is strikingly shown by 

 the experience of the San Francisco in de- 

 stroying the derelict three-master Drisko 

 a decade or so ago. That derelict was 

 only 248 tons, but she was lumber-laden. 

 The officers of the San Francisco first 

 tried to tow her to port, but found that 

 impossible. Then they attached three 30- 

 pound gtmcbtton bombs to her keel and 

 set them of! ; but still she floated. Five 

 more bombs were set off ; these broke her 

 back and frames, but still she refused to 

 go to the bottom. Then the San Fran- 

 cisco rammed her amidships and broke 

 her in two, releasing the cargo ; but even 

 after that it took several shells to drive 

 the after part of the staunch old schooner 

 down into the jurisdiction of Davy Jones. 



Even in peace times ships are often re- 

 ported missing and appear to have been 

 "sunk without trace." It is believed that 

 most of such catastrophes are the results 

 of collisions with derelicts. How many 

 more such collisions there will be in the 

 future may be imagined when it is stated 

 that for two years the number of dere- 

 licts has greatly increased and the steps 

 for their destruction have been much re- 

 duced. 



KEEPING TAB ON THE DERELICTS 



In normal times the Hydrographic 

 Office of the Navy Department keeps 

 careful check on the derelicts. Every 

 ship that sights one of these menaces to 

 navigation reports its location. The 

 names of some of them remain visible, 

 while others are susceptible of identifica- 

 tion by their appearance. The Hydro- 

 graphic Office gives each wreck and dere- 

 lict a serial number and plots its position 

 on a map. Each report is registered with 

 an identification number. In this way, by 

 a system of cross-checking, it is possible 

 to identify each derelict, to determine the 



