204 



DISCOVERY REPORTS 



inspection of bridles and throttling line had shown that all were clear and properly 

 adjusted, a snatchblock was placed on the rope in front of the gear and the rope hauled up 

 until the apparatus could pass clear of the fair-lead. The net was now put out, the frame 

 lowered and tripped, and as soon as all was clear and well away the rope was slackened 

 back into the fair-lead. On some occasions a second net and mechanism were added at 

 an intermediate point on the wire, with messengers slung below the stop to operate 

 the release of the lower net. It is no doubt possible to shoot a whole series of closing 

 nets on the one warp, and, as explained above, this has been managed very successfully 

 with small nets worked at shallow depths. 



TRAWLS, DREDGES AND OTHER APPARATUS 



The scientific programme for the ' Discovery ' did not include trawling and dredging 

 at great depths, and work on the bottom was for the most part limited to areas in the 

 south where the depth did not exceed 6oom. Plankton and hydrography were, moreover, 

 the subjects with which this vessel was more particularly concerned and investigation 

 of the bottom fauna was only undertaken at irregular intervals. As has already been 

 explained, a trawling survey of the grounds lying between the Falkland Islands and the 

 South American coast formed part of the work of the 'William Scoresby'. 



Trawls. The trawl in the ' William Scoresby' has a headline 80 ft. long and is made to 

 the specification shown in Fig. 23 : it was used with otter-boards 10 ft. long and 4 ft. 4 in. 



ibuesHcs 



joMjjm 



iOMCSHlS 



Fig. 23. Plan of otter trawl used in the R.S.S. 'William Scoresby'. 



high, fitted with brackets. The trawl used in the 'Discovery' was a small one, with 

 head-rope 40 ft. in length, made to the specification shown in Fig. 24; the otter-boards 

 were 5 ft. long and 2 ft. 11 in. high, fitted with chains. 



