370 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
in place. The half of the ring opposite the union is filled with lead, which gives it 
a preponderance of about 10 pounds. 
The arms h are of brass pipe of the same diameter as that of the ring; the lower 
ends are screwed into tees which move freely on the ring between those above 
mentioned, the upper ends having a hinge joint held in place by the shackle pin. 
The legs c, four in number, are also of brass pipe, ^ of an inch outside diameter 
and 5 feet 5^ inches total length, with net length (from lower side of ring to apron) of 
5 feet. The lap of legs over the apron is inches, and the upper ends screw 1 inch 
into their respective tees. 
The apron d is of sheet brass J inch thick, 18 inches in length; straight on the 
upper edge, the lower i>art semicircular with a radius of 10 inches. It is secured to 
the flattened extremities of the legs by two screwbolts e in each end, inch in 
diameter and inches in length. An oblong hole in the central upper part of the 
apron is for the purpose of securing the tail of the net, in order to prevent its floating 
up or becoming entangled while being lowered. 
The functions of the apron are threefold : First, to afford rigid and secure fastenings 
for the lower ends of the legs; second, by its form to aid in guiding the net down 
vertically when lowering, and. Anally, to give the apparatus a tendency to take a 
horizontal ijosition when towing, thus increasing the area of collecting surface within 
the ring. The heavy weights are all at or near the ring while the net is being lowered 
and towed, and there is a preponderance of 70 pounds on one side of it, so placed as 
to cause the apron to expose its flat surface to the water and greatly increase the 
tendency of the light rear end to seek the level of the more ponderous weighted ring 
whenever it is moving forward. 
Bloelcs f, four in number, for operating the drawstring, are of brass, inches in 
length. Two of them are secured to a pair of legs by through bolts, riveted 2 feet 4 
inches above the apron; the others are seized with wire to the tees holding the upper 
ends of the other j)air of legs, upon which the movable weights traverse. 
The movable weights g, of lead, two in number and weighing 30 pounds each, are 
provided to put the recprired tension on the drawstring when it is desired to close the 
net. They are egg-shaped, 4 inches in diameter by 9 inches long, and have an inch 
hole through the center; |-inch holes in lugs at their upper extremities furnish a 
convenient method of attaching the drawstring and tripping lines. 
The sinker h is of cast iron, 130 pounds weight, oblong in form, with projecting 
links of wrought iron at each end, through which shackles for attaching tow net and 
dredge rope pass. The sinker is used to facilitate lowering the net, and to i>revent 
kinking the steel dredge rope or tow line. 
The friction clamp i is composed of brass and steel, the barrel of the former metal, 
the eccentric tumbler k, sliding chocks, striking face, and adjusting screw of the latter. 
A small steel wrench m is provided to work the adjusting screw. 
The messenger I is of cast iron, 9 pounds in weight, made in halves, with two 
scores on the external surface for convenience in passing lashings. To use it, pass 
the halves over the rope and take a few turns of a lashing. The hole in the messenger 
is sufficiently large to allow it -to pass freely over splices in the dredge rope. 
The net n is ^-inch square mesh; thread 24-6 stow, barked; it is seized to the 
ring with seine twine, and hangs 5 feet 6 inches in length, the same size throughout. 
It is lined with mosquito netting the whole length, and there is an inner lining of silk 
gauze extending up 3 feet 6 inches from the lower end. The outer net is intended to 
