NARRATIVE OF THE CRUISE. 



57 



Sounding. — The apparatus used to obtain soundings consisted of— (1) a deep-sea 

 sounding line ; (2) a reel on which this line wa3 kept ; (3) a number of sinkers ; (4) 

 an apparatus for detaching the sinkers when they reaehed the bottom, technically termed 

 a sounding rod ; (5) some iron wire and discs to attach the sinkers to the disengaging 



Fig. 12. — Oredging and Sounding arrangements on board the Challenger. 



apparatus during their descent ; (6) a number of india-rubber bands, technically termed 

 accumulators ; and (7) some iron gin-blocks with patent sheaves for the line to reeve 

 through. 



Sounding Lines. — Two kinds of sounding line were supplied, the first being 1 inch 



(NAIiR. CHALL. EXP. — VOL. I. — 1884.) 8 



