202 



THE SEA FLOOR 



A TJ 



II 



Fig. 157. — Baillie Sounding Machine as used on Board 

 H.M.S. " Challenger." 



A, In elevation ; B, in section. The heavy weights, e, drive the 

 central tube, a, into the bottom deposit, and the ooze is retained 

 in the tube by the butterfly valve, /. As soon as the suspension 

 is relaxed, the shoulder carrying the wire which holds up the 

 heavy weights becomes sheathed, the wire and weights being 

 left on the bottom. 



