356 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
tliiis forming- the ]>ocket. The double bridle is seized to the ring through the net and 
serves to hold it in place. The tail lashing is sewed to the end of the net to prevent 
its being- lost when cast adrift. There is a drawsti'ing in the end of the pocket and 
a cord, with a knot in its lower end, is secured to the pocket and allowed to hang 
down far enough to be gathered in with the end of the net, and secured with the 
lashing to prevent its turning inside out when the trawl first takes the water. The 
arms are of wood, with deep scores for the reception of the bridles. 
The mud hag is simiily a boat dredge minus its net; the lower end of its canvas 
shield is closed for the purpose of bringing up an unwashed specimen of bottom soil. 
A detailed description will be found under the title of “boat dredge.” 
THE TANNER BEAM TRAWL NO. 2. 
This trawl is a duplicate of No. 1, except that it is smaller and lighter, being 
esjiecially designed for use in heavy weather when No. 1 can not be safely operated, 
or on doubtful or foul ground where the apparatus is liable to be sacrificed. It is 
much used also for rapid towing in shallow water in the examination of fishing banks. 
Its dimensions are as follows: 
Beam ; Iron pipe, length, 7 feet 6 inches ; ontside diameter, 2^ inches ; thickness of metal, inch. 
Collars, brass; width, 2 inches; thickness, i inch; length of llanges, 7 inches; diameter of bolts, 
f inch. 
Runners: Length, 4 feet; height, 2 feet 3 inches + 3 inches for height of beam; total, 2 feet P 
inches; width, 2 inches; thickness of metal, finch. 
Weight of trawl frame, 140 pounds. 
Rojie for bridle, 24 inches ; manila. 
Rope for lead rope, 2 inches; manila. 
Rope for head rope, If inches; manila. 
Trawl net: Length, 17 feet; size of mesh, square, 1 inch; material, cotton, barked, 30-thread; 
pocket, length, 6 feet; pocket, size of mesh, square, 1 inch; pocket material, cotton, barked, 
21-thread; jacket, length, G feet; jacket, size of mesh, square, 4 inch; jacket material, cotton, 
barked, 16-thread. 
Float : Norwegian glass globe, diameter, 6 inches. 
THE TANNER BEAM TRAWL NO. 3. 
This handy little trawl has the same general form as Nos. 1 and 2, and is espe- 
cially designed for boat service. It was first used in March, 1804, for the scientific 
exploration of San Diego Bay, California, when it was so highly appreciated that it 
was at once adopted as a part of the dredging outfit of the vessel. Its dimensions are 
as follows : 
Beam: Iron pipe, length, 3 feet 6 inches; diameter outside, If inch. 
Bolts: Iron, square; diameter, 4 inch. 
Runners: Iron, Hat bar, If by f inch; length, 2 feet 7 inches; height, 1 foot 1 inch. 
Weight of frame, 16 pounds. 
Net: Material, cotton, barked, 21-thread; size of mesh, 1 inch square; length of net, 7 feet; 
jacket material, cotton; thread, 24-6 stow, barked; size of mesh of jacket, f inch square; 
length of jacket, 2 feet 6 inches. 
Rope: Head, leech, lead roiies, and bridle, 9-thread manila; tow rope 15-thread manila. 
The several parts of the frame are secured by close-fitting square bolts through 
holes in the runners and flattened ends of the beam, set up with nuts. The legs of 
the bridle are secured to the runners with light seizings, and the ends extended to 
the tail lashing, as in Nos. 1 and 2, for the purpose of recovering the net tail first, in 
case the trawl is caught on the bottom and the bridle stops part. 
