228 CHALLENGER 



The German ship Planet shifted the scene of greatest depth 

 once again to the northern hemisphere — in the PhiUppine Trench 

 close eastward of the islands which give it the name. And here 



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some years later the Dutch vessel Willebord Snellius subsequently 

 found 5^5^39 fathoms, using early audio -frequency sounding 

 methods. 



The U.S.S. Ramapo moved the scene once more to the Japan 

 Trench with 5^673 fathoms, using audio-frequency methods, but 

 the German Emden, returning to the Philippine Trench, foimd 

 just a few more fathoms to make it ^686. 



This was the state of great depth sounding when World War 

 II came. But at the close of the Pacific War the United States was 

 once again to take the lead in the friendly rivalry of deep ocean 

 discovery. Dr. H. H. Hess, a University Professor, had studied 

 the shape of the ocean floor for many years and had produced the 

 best bathymetric chart of the North Pacific available before the 

 war. Like so many others of his calling, he joined the Services and 

 his knowledge of the sea took him into the Navy, where he 

 eventually commanded a large Fleet oiler, the U.S.S. Cape Johnson. 



Commander Hess's crew was colnposed of reserves and he had 

 no difficulty in persuading them that it was normal in the Navy 

 to carry out standard oceanographic observations as the vessel 

 proceeded upon her naval duties across the oceans. Thus this 

 ship was able to add much to the knowledge of oceanography and 

 eventually sounded with her echo sounding machine in the Philip- 

 pine Trench, recording there a depth of ^740 fathoms, now 

 known as the 'Cape Johnson Depth', from which the Danish 

 research ship Galathea later dredged up forms of life including 

 small sea anemonies, a number of worms and some living 

 bacteria. 



The scene of the greatest depth having once again shifted to 

 the Marianas Trench, Challenger was determined to make a survey 

 of the deep area and to get a sample of sediment from the depths. 

 During the visit to New Zealand the ship enjoyed great assistance 

 from knowledgeable technicians in the Royal New Zealand Dock- 

 yard at Devonport who managed to boost the echo sounder to 

 record at the greatest depths; here also extra wire for the 

 sounding machine was obtained. 



It was an exciting moment as Challenger steamed back into the 



