570 FISHERIES OF THE UNITED STATES. [58] 



of the net have a one-fourth-inch square mesh. The lower edge is fur- 

 nished with a lead line and the upper edge with a line of wooden floats. 

 A pole is fastened at each end as a means of handling it. This style 

 of seine has proved very convenient for exploring parties on account of 

 its small size, and is in constant use in the exploring work of the United 

 States Fish Commission. Only two persons are required to manage it. 

 It was designed some years ago by Prof. S. F. Baird, United States 

 Fish Commissioner, whose name it bears. 



Dip Net for scraping the piles of wharves, bridges, &c. 

 United States Fish Commission. 

 This is similar in construction to an ordinary dip-net, but is made of 

 thicker iron, and has the outer side straight and broad, with a sharp 

 edge for scraping. It is attached to a long pole and furnished with a 

 coarse linen net. The common styles of dip-nets are shown in the sec- 

 tion of fishery appliances. For natural history purposes they are gen- 

 erally fitted with bags of fine netting or coarse cloth. 



ACCESSORY APPLIANCES USED IN CONNECTION WITH 

 DEEP-SEA DREDGING AND TRAWLING. 



Steel Wire Dredge Eope, showing the methods of splicing two pieces to- 

 gether, of attaching the dredge, &c. 



United States Coast and Geodetic Survey and United States Fish Com- 

 mission. 



The wire rope used by the United States Coast Survey and United 

 States Fish Commission for dredging purposes is made at Trenton, 

 N. J., by the John A. Roebling's Sons Company. It is one and one- 

 eighth inches in circumference, and is composed of six strands, laid 

 around a tarred hemp heart. Each of the six strands consists of seven 

 galvanized steel wires, of No. 19 American gauge (No. 20 Birmingham 

 gauge). The ultimate strength of the rope is 8,750 pounds. It weighs 

 1.14 pounds to -the fathom, in air, and about 1 pound to the fathom in 

 sea-water. ♦ 



Wire rope for dredging purposes was recommended by Prof. Alex- 

 ander Agassiz in 1877, and was first put to trial on board the United 

 States Coast Survey steamer Blake, in the winter of 1877-'78, during her 

 first dredging cruise, Commander Charles D. Sigsbee, United States 

 Navy, being in command, and Professor Agassiz in charge of the dredg- 

 ing operations. 



Commander Sigsbee describes his experience with the wire rope as 

 follows: "The adoption of steel-wire rope, although presenting to our 

 minds at the outset a few difficulties which we confidently expected to 

 overcome after a short experience, simplified matters as compared with 

 what had previously been thought proper in a dredging outfit. Before 



