BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 



39 



disc fourteen inches in diameter, and we likewise used a four candle- 

 power electric light with storage battery, in a water-tight brass case 

 with glass window at the top. 

 The following nets were used: — 



1. Four foot open net for horizontal towing, of the Albatross 

 pattern; ten ft. long, the upper five ft. with i in. mesh, the lower five 

 ft. lined with silk, 38 meshes to an inch. A glass bucket was some- 

 times used with this net, and a 70 lb. weight attached to the wire rope. 



2. Quantitative nets of the Hensen type, the opening of the net 

 36 cm. in diameter, with glass collecting-bucket, and a 70 lb. weight 

 attached to the latter. Nets of two grades were used, the silk of one 

 being 74 meshes to the inch, the other 144 to the inch. 



3. Ordinary open net of no. 20 bolting silk, 18 inches in diameter. 



4. Open net 12 inches in diameter, silk 38 meshes to the inch. 



5. A scrim net 18 inches in diameter. 



6. A closing net for horizontal towing. 



This net, described in Int. rev. hydriob., 1913, 5, p. 576, is a com- 

 bination of the Chun-Petersen-Nansen principles, i. e., it has a hinged 

 ring which is sent down closed, to be opened by a spring released by 



Fig. 2. — Closing net in operation. 



a messenger; and it is closed by a draw-string about the net bag, 

 likewise operated by messenger (fig. 2). . i • 



Trawling and dredging were a minor part of our program; for this 

 work we carried ordinary dredges, and eight-ft. beam trawls. 



The four-ft. and closing nets were towed horizontally, sometimes 

 separately, sometimes simultaneously on the wire rope. In the latter 

 case, the former was necessarily used at the deepest, the latter at the 

 intermediate horizon. In the shallow waters in which we worked 

 the catenary of the rope is so small as to be practically negligible; 



