t> SUBMARINE CABLE LAYING AND BEPAIKING. 



jerk the sounding line to give the cut, especially if the knife is 

 at all blunt or out of adjustment, and this is liable at times to 

 break the line. To avoid this possible danger to the line 

 Mr. Edward Stallibrass has devised a detaching gear in which 

 the wire sling is simply thrown oflF its seat instead of being 

 cut (Fig. 4). The ring at the top is one with a plunger, which 

 carries a small stud working in a slot in the upper tube. When 

 the apparatus is suspended from the ring the plunger takes the 

 highest position (as in the figure) and the sling supporting the 

 Aveight is held in the notch above the tumbler. On striking 



Wire Sling 

 for Weight. 



FiQ. 3. — Silvertown Detaching Gear. 



bottom and the wire slacking, the plunger is pulled down by 

 a spiral spring inside, and the stud, descending with it, 

 engages between the two projections of the tumbler. When 

 picked up on board ship the tumbler is turned by the 

 stud so as to present an inclined surface to the sling, causing 

 it to roll oflf and release the weight. The form of water 

 and mud collecting tubes are similar to those in the Silvertown 

 apparatus. 



When it is not required to recover a sample of the 

 bottom water the large tube is dispensed with and a lin. 

 iron gas pipe substituted, as at A B, Fig. 5. The tube passes 



