JoLY — On the Investigation of the Deep-sea Deposits, 261 



being witlidrawn, the valve closes, and thus preserves the ooze within the drill 

 from falling out or remaining behind. This can only happen if the water 

 makes its way past the ooze to the top of the tube. 



The drill-tube may be made in various forms adapted to different condi- 

 tions of the bottom materials. It is intended in the first instance to use a 

 plain, drawn-steel tube, with projecting ribs running longitudinally for 

 engagement with the driving-collar. The lower cutting extremity may be 

 recessed outwards by a groove which receives a ring sprung into its place, 

 and which serves to retain in position a lining of oil-silk, which extends 

 throughout the entire length of the tube, or the oil-silk lining may be 

 cemented to the tube at its lower extremity. The function of this lining is 

 to enable the contents of the tube to be readily removed for examination 

 without mixing its contents longitudinally. The entry of the drill is a little 

 narrowed in order to lessen the friction of firm materials entering the tube. 



When the sounder is about to be raised from the bottom, the haulage first 

 comes upon the drill-tube, and not until this is brought home, and its lower 

 extremity brought within the sounder, is the pull transferred to the latter. 

 An examination of Plate XX shows how this is efl'ected. The sounding-line 

 is passed through the floating tube I. Within this tube it is nipped by the 

 steel nippers g, g. These act only so long as the weight of the sounder is on 

 the lowering wire, being then jammed by friction with the wire in the 

 position shown. When the weight is removed, upon the sounder reaching the 

 bottom, the grip-jaws open. During descent a certain amount of slack wire 

 is preserved coiled upon the upper deck d. This is for the downward feed of 

 tlie drill into the ooze. When the sounding-wire is hauled from above, it 

 passes freely through the open jaws of the nippers g, g, and the drill is lifted 

 from the mud. The lifting wire runs througli the floating tube till the stop p 

 is arrested against the aperture of the tube, when the stress is transferred to 

 the suspenders leading to the sounder. In the event of the drill-tube being 

 for some cause so tightly fixed in the mud as to endanger the lowering wire, 

 the connection with the tube below the stop 7; first ruptures, leaving the 

 drill in the mud. This is accomplished by removing some of the component 

 strands from the lifting wire between the stop and the attachment to the top 

 of the drill-tube. 



The drill-tube is guided in its descent by the two guides, n, n, which are 

 stayed by the four stays, s, s. These guides and stays are readily unbolted 

 from the deck for convenience of stowing. 



It is intended to use a sounding-wire of sufficient strength to ensure the 

 safety of the sounder. The weight of the whole apparatus may amount to 

 about 250 lbs. (114 kilos.). The sounding- wire should have a breaking stress of 



