[91] U. S. FISH COMMISSION STEAMER ALBATROSS. 93 



TRAWL WEIGHTS. 



It is customary with us to attach one or more trawl weights to the 

 tail of the trawl net, and, in shoal water, one to each runner. Two or 

 three are also used with the dredge and tangles. 



DIMENSIONS. 



Length, 11 inches. 



Diameter of base, square, 4 inches. 



Diameter &J inches above base, 3 inches. 



Size of hole, 1 inch by If inches. 



Thickness of metal around hole, three-fourths of an inch. 



Material, cast iron. 



Weight, 27 pounds. 



THE TANGLE BAR (PLATE L). 



The form of tangle bar used was devised by Prof. A. E. Verrill in 

 1873, and consists of an iron bar supported at each end by a fixed wheel, 

 or iron Loop. Six chains about 12 feet in length are attached to the bar 

 at intervals of 1 foot. To these chains are secured deck swabs, or bun- 

 dles of rope yarns, at intervals of about 18 inches. 



It is very useful on rocky bottoms where it will capture specimens 

 when no other device could be made available. 



DIMENSIONS. 



Wheels : 



Diameter, 1 foot 2 inches. 



Width, 1\ inches. 



Thickness of iron, one-half inch. 



Width of cross-bars, 2J inches. 



Thickness of cross-bars, three-fourths of an inch. 

 Chain bar: 



Length, 6 feet. 



Width, 21 inches. 



Thickness, 1 inch. 



Rings for drag rope, diameter, 4 inches. 



Rings for drag rope, diameter of iron, five-eighths of an inch. 

 Tangle chains : 



Diameter of iron, three-eighths of an inch. 



Length, 12 feet. 

 Tangles, hemp, length, 3 feet. 



THE TANGLES. 



The tangles, Plate LI, were devised by the writer in 1884 as an im- 

 provement on the tangle bar, being less liable to foul on the rough 

 rocky bottoms where it is generally used. 



NOMENCLATURE. 



a. Bow. 



I. Tangle bars. 



c. Tangles. 



d. Eyebolts. 



e. Bolts and nuts. 



