[57] FISHERIES OP THE UNITED STATES. 5G9 



Having secured the buffer to the" rope about 5 or 6 fathoms above 

 the lead (a very heavy lead to keep the steel rope straight) and paid 

 out the length of rope required to span the stratum to be explored by the 

 cylinder, the clamp and cylinder are attached, the latter being suspended 

 from the former as follows : The rope having been placed between the 

 two binding chocks of the clamp, the arm of the eccentric tumbler is 

 thrown up, which moves one of the chocks inwards ; then, by means of the 

 clamping screw, the other chock is pressed against the rope, securing 

 the clamp in position. The cylinder hangs 4 or 5 inches below the 

 clamp and is supported by a loop of soft wire which rests on the lip of 

 the tumbler; the ends of the wire, being rove through holes in the upper 

 part of the frame of the cylinder, are fastened permanently to the outer 

 arms of the lever to which the valve is screwed. It is seen that by this 

 method of suspension the weight of the cylinder and its frame is used to 

 keep the valve closed while paying out.* The cylinder should be filled 

 with water poured down through the upper sieve, to maintain the valve 

 on its seat while the cylinder is being immersed. Eope is then paid 

 out slowly until the cylinder is at the desired depth, when the rope is 

 stoppered and the messenger sent down. 



The messenger strikes the arm of the eccentric tumbler, throwing it 

 down and tripping the cylinder. The tumbler in falling relieves the 

 pressure on the binding chocks, which are then free to recede from the 

 rope. Messenger, clamp, and cylinder fall together, the valve being 

 held open by the resistance of the water. A current is established 

 through the cylinder, and specimens which enter are retained by the 

 upper sieve. When the buffer is reached, the valve is closed by the 

 pressure against the outer arms of the lever. 



A very slight pressure on the clamping screw of the friction clamp, 

 after the chocks are bearing against the rope, is enough to prevent the 

 clamp from slipping, but by an increased pressure on the screw a greater 

 force is required to trip the tumbler, and by this feature the arm of the 

 tumbler is utilized to break the force of the blow which the body of the 

 clamp receives from the falling messenger. A few rings of sheet-lead 

 may be laid on top of the clamp and the buffer respectively. 



Baird Seine for the use of naturalists in collecting along the margins of 

 the sea, lakes, and rivers. 



Boston Net and Twine Company. 



These seines are made of several sizes, from 9 to 16 feet iu length 

 and from 2£ to 4 feet in height. The center consists of a large and deep 

 pocket, about 3 feet long, with a one-eighth-inch square mesh; the sides 



* It is suggested that, in lieu of the soft wire sling, the friction clamp be constructed 

 to receive the end of a stiff wire rod, proceeding from the ends of the valve levers, and 

 that it be done in such a way that, when the valve is closed and the rod connected 

 with the clamp, the bottom of the latter will be in firm contact with the upper part 

 of the cylinder frame. Such an arrangement would effectually guard against the 

 opening of the valve with any rapidity of descent. . 



