12 



THE VOYAGE OF H.M.S. CHALLENGER. 



the figure on the dredge-frame are only to protect the seizings of the loops. The dredge 

 is suspended from an inch iron chain which forms the first few fathoms of the dredge 

 hne, and resists chafing more efi'ectually than rope would do. 



The chain is not, however, directly fastened to the ring at the end of the arms of the 

 dredge, but is made fast to one of the end bars of the dredge-frame, and is strapped to the 



Fig. 8.— The form of Dredge used on board the Challengee. 



ring by a single strand of bolt-rope, so that if the- dredge by any chance catches, the 

 seizing gives way, and, by altering its position and throwing the strain in a different 

 direction, gives a better chance for its recovery. The iron bar which runs across the 

 bottom of the dredge-bag is of inch square iron and about 5 feet long, and to it are 

 attached about eight hempen tangles or swabs. In deep water a 28-lb. deep-sea lead is 

 usually hung from the centre of the tangle-bar with four tangles on each side. 



