282 REPORT OP COMMISSIONER OF FISH AND FISHERIES. 



mediate net sometimes brought up forms not taken at all in the surface 

 net. The towings, 18 in all, were made along the border of the sub- 

 marine bank south of the Pribilof Islands during the month of August, 

 from lat. 54° to 5G° N. and long. 107° to 172° W. Soundings were from 

 75 fathoms, on the bank, to 1,901 fathoms beyond it. There can be no 

 doubt that there is an abundance of pelagic life at 200 fathoms in this 

 part of Bering Sea. 



After some experience with the single tripping-arm described in the 

 preceding pages, I designed a machine for opening as well as closing 

 the jaws of the tow-net, which worked satisfactorily (plate 10). It is 

 a combination of two tripping arms, for operating which two messengers 

 are employed on the same tow-line, the second striking a separate 

 detacher from the first. A rough experimental machine, constructed 

 on board the Albatross, was used successfully in port, but did not have 

 strength to withstand the strain of towing at sea. Experiments indi- 

 cate, however, that a properly constructed machine of the same pattern 

 would accomplish the desired result. Its use in place of the single 

 tripping-arm permits of the folding-ring tow-net being lowered in a 

 closed position, the closing-slings being attached to the right arm, the 

 opening-slings to the left. The arms are bolted to a bar of brass about 

 2 feet long, suspended from the towline, and in position for use are 

 hooked upright to detachers released by messengers. The first mes- 

 senger tripping the right arm, the jaws of the net fall apart for towing. 

 The second messenger, in turn, tripping the left arm, the weight is 

 thrown back on the slings of the right arm, closing the jaws. A ring- 

 shaped weight around the right slings, and suspended from a hook on 

 the left arm, holds the jaws together for lowering. It is released upon 

 the tripping of the left arm, and slips again to its position upon the 

 right slings, holding the jaws together for heaving in. 



The net being closed tightly in going down, it is not necessary to 

 stop the vessel and lower it vertically. 



