LVIII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

 E.— SUPPLEMENT TO REPORT PROPER. 



19. — ON THE WORK OF THE FISH HAWK AND OF THE UNITED STATES 

 FISH COMMISSION DURING THE YEAR 1881, BY PROF. LESLIE A. LEE, 

 OF BOWDOIN COLL"EaE.* 



The Fish Hawk is fully equipped with all necessary apparatus for con- 

 ducting the investigations. The experience of the Commission has been 

 so great that the apparatus for dredging, trawling, «&c., is probably 

 more perfectly adapted for its purposes than any which has been used 

 elsewhere. Many important improvements have been suggested from 

 time to time by members of the Commission, and changes are continu- 

 ally being made. Perhaps the most important addition to the appa- 

 ratus this season was in the " trawl-wings." A large net-trawl is used 

 more than anything else for obtaining bottom animals, and it has long 

 been supposed that many of the more active ones escaped capture by 

 swimming to one side after being aroused by the on-coming trawl. To 

 capture these the trawl- wings were contrived. These are light nets 

 which are attached to rods which run out on each side from the top 

 of the trawl. The nets are fitted within with a transverse partition, 

 perforated in the center, which prevents the escape of the animals after 

 they are once confined. This arrangement was a complete success, 

 many new species being taken by it. 



But not all the energies of the Commission are devoted to the collec- 

 tion of specimens. Careful soundings are made by which the existing 

 charts are often corrected. The temperature of the water is taken at 

 all depths, particularly at the surface and bottom; and the specific 

 gravity of the bottom water is determined. In fact a complete record 

 is made of everything which can be supposed to have a bearing upon the 

 subjects before tlie Commission. 



Upon the prospect of pleasant weather the party would go aboard of 

 the Fish Hawk and proceed directly to the southward, remaining off 

 shore for from two to four days. Nine such trips were made during the 

 past season. The Gulf Stream off" the coast of Southern New England 

 is situated about 100 miles from land. Its distinctness as a stream is 

 well indicated by the soundings. The depth of the water from Gay 

 Head outward is very uniform for nearly 90 miles, not more than 50 

 fathoms often occurring. Then comes the beginning of the slope. 

 Within 10 or 15 miles 1,000 fathoms and probably greater depths can 

 be reached. The work of the Commission was done in depths of less 

 than 800 fathoms. 



Upon reaching suitable ground, as indicated by the soundings, the 

 trawl or dredge would be put over and allowed to drag on the bottom 

 for perhaps twenty minutes. Or, if fish were desired particularly, the 

 line-trawl, similar to that used by cod-fiShermen, would be set. Upon 



From a paper read before the Portland Society of Natural History January 16, 1882. 



