EQUIPMENT. 27 



bly, obviating all fouling, and doing away with the frequent 

 delays so annoying when the ordinary single-beam trawl is used 

 in deep water. It was practically a double trawl, bearing the 

 same relation to the old beam-trawl which the ordinary dredges 

 bear to the old oyster dredge, and sure to do its duty, on what- 

 ever side it might happen to fall ; the runners were made ellip- 

 tical, high enough to give fair scope to the lead line of the 

 trawl, and thus it became a matter of indifference on which 

 side of the runners the trawl landed. Under these conditions 

 the hauls were always successful. 



At great depths, where a Hght ooze covers the bottom, the 

 trawl soon becomes completely filled with the mass of sticky 

 mud which finds its way into it ; and when brought to the 

 surface it is found that but little has been washed out throuo^h 

 the meshes of the trawl-bag. The labor of sifting this large 

 mass of mud (often as much as a ton) is very considerable. 

 It is done by washing off the mud in sieves provided with 

 handles, and shaken in tubs of water. The United States 

 Fish Commission use a table-sieve upon which plays a hose; 

 this quickly disposes of a large amount of mud. It became im- 

 portant to do the sifting as far as practicable while trawling. 

 To accomplish this, the bag of the trawl was greatly shortened 

 (reduced to fifteen feet), and the meshes of the outer net made 

 coarse, while only a very small part of the bag was fine enough 

 to allow the accumulation of mud. The result proved the wis- 

 dom of this change. We were now rarely overwhelmed with the 

 masses of mud which had rendered so much additional work of 

 sifting necessary during the first cruises. After this change it 

 also became possible to drag the trawl with considerable rapidity 

 over the bottom (sometimes as fast as three and one-half miles 

 an hour), and thus to catch the more active fishes and Crus- 

 tacea, which keep out of the way of the trawl when it moves 

 slowly. We also tried dragging a heavy tow-net rapidly over 

 the ground at great depths, in hopes of accomplishing the same 

 object ; but we found that, after all, no deep-sea machine worked 



yeare of dredging and sounding o£E the count of the apparatus will be found in 

 coast of the United States in the " Fish the Annual Reports of the United States 

 Hawk" and "Albatross." A full ac- Fish Commission. 



