NO. 1 FRASER : SCIENTIFIC WORK, VELERO III, EASTERN PACIFIC 41 



trolled, to a 1,000-fathom cable capacity drum, operated by a winch, 

 which allows for different speeds and is controlled by shift gears. A con- 

 tact wheel meter is used to record the amount of cable let out or hauled in. 



To lower the dredge to the surface of the water, or to raise it and 

 bring it inboard so that the contents may be dumped on the screens, the 

 cargo boom is used over the starboard side. 



The dredge itself is much the usual type. It consists of two steel jaws, 

 3' 6" long, held 12" apart by steel bars near each end. The steel arms are 

 attached to the crossbars in such a way that they may swing through an 

 arc. Eyes at the other end of the arms are lashed together by heavy twine, 

 and the shackle from the cable is attached to one of the eyes. 



The inner bag of the dredge is of %'mdi mesh, the outer of 1-inch 

 heavy mesh. Both are closed at the bottom, when in use, by a rip cord. 

 Within the larger inner net is a smaller burlap net, fastened to the inner 

 net near its mouth, to retain some of the finer material that would pass 

 through the meshes of both inner and outer nets, and a sample of the sand 

 or mud through which the dredge may be hauled. The nets are protected 

 by a steel chain net. Commonly (in recent trips, almost always), tangles 

 are attached to the free edge of the chain net, instead of being used sep- 

 arately. 



The screens used for sorting are three in number, the frame of one 

 fitting exactly to the frame of the one below. The topmost has the coarsest 

 mesh, and the lowest, the finest. The material is washed with a sea-water 

 hose, and the usable material is picked out from each screen in turn and 

 roughly sorted before it is taken to the laboratories for further sorting 

 and preservation. If much fine stuff collects on the lowest screen, it may 

 be put into buckets or jars for tray washing, so that as much of the ma- 

 terial as is possible may be saved. 



The small dredge, with jaws 2' 6" long and 8" apart, is similar to 

 the large dredge, but has not the inner bag. It is operated from one of 

 the motor boats that has been especially fitted for the purpose with a 

 winch and drum of 250 fathoms of cable, platform table, and an A-frame, 

 movable through an arc, the block for the cable being at the angle of the 

 A-frame. Aft of the winch there is a cockpit in which the dredge operators 

 may stand, with the sorting table at suitable height. A small beam trawl, 

 6' 0" long, with an opening 15" wide, is handled from the motorboat in 

 the same way as the dredge, when bottom conditions are suitable. 



The deep-sea water bottles with their reversing thermometers and 

 the bottom samplers are operated from the port side of the Velero III. 



