THE DEEPEST DEPTHS 229 



trench on the way northwards from Manus to Japan, for this time 

 she was not restricted to spot soundings here and there ; enthus- 

 iasm rose as the water became deeper and deeper, and still the 

 officer with headphones sitting before the sounder could hear the 

 small answering signal returning from the depths first eight, then 

 slowly nine, ten, eleven, twelve and finally fourteen seconds after 

 the metallic sound of the outgoing signal had been heard. For 

 such is the time the sound takes to reach the sea-bed and return 

 from ^900 fathoms. 



Sounding lines were run at right angles to the east-west axis 

 of the trench thus obtaining profiles across this giant crack on the 

 surface of the globe. Such trenches do not have spectacular slopes 

 as one might find in a canyon on land, but descend slowly and 

 steadily to meet in a small flat expanse at the bottom of the trench 

 from which the echo returns more loudly and clearly than from 

 any other part. On completion of the mapping it appeared that 

 there was a considerable area of a depth greater than ^900 

 fathoms and that a sounding of 5^940 fathoms existed. But the 

 6000 fathom barrier remained inviolate. 



A sample from the trench was obtained with the Baillie rod 

 after three attempts. It is difficult when using the steam sounding 

 machine in such depths to know just when the sampler has 

 reached the bottom, and during the short delay between realising 

 that the bottom has been reached and the application of the brake 

 to stop more wire running out, a certain amount of the wire will 

 have coiled itself upon the sea-floor beside the sampler. When 

 the winch begins to heave, these coils become kinks, and often, 

 perhaps hours later when the sample seems to be almost on deck, 

 the wire finally parts at the kink and the six-hour task has to be 

 done all over again. This difficulty was finally overcome by laying 

 up the whole of the last 100 fathoms of piano wire within a piece 

 of rope which obviated the kinking as the superfluous wire coiled 

 onto the sea-bed 6| land miles below. 



Excitement on deck w^as tense when, at long last, the ceaseless 

 chugging of the winch was slowed and Petty Officer Greenshields 

 grasped the rope and hauled in hand-over-hand. Even before the 

 sampler could be clearly sighted a brown cloud was seen spreading 

 from it, indicating that the rod must contain a sample of what 

 the surveyor has termed 'red clay' , the deposit of the great depths. 



