[97] U. S. FISH COMMISSION STEAMER ALBATROSS. 99 



tically instead of horizontally, as formerly, there would be as much cer- 

 tainty with regard to depths as in the old method, and that simple 

 mechanical devices could be invented to satisfy the conditions of the 

 work. The scheme has been stated in my volume on Deep sea Sound- 

 ing and Dredging (p. 145, foot-note) as follows : 



"'Our plan is to trap the specimens by giving to a cylinder, covered 

 with gauze at the upper end and having a flat valve at the lower end, 

 a rapid vertical descent between any two depths as may be desired, 

 the valve during such descent to keep open, but to remain closed dur- 

 ing the process of lowering and hauling back with the rope. An idea 

 of what it is intended to effect may be stated briefly thus : Specimens 

 are to be obtained between the intermediate depths a and 6, the former 

 being the uppermost. With the apparatus in position, there is at a 

 the cyliuder suspended from a friction clamp in such a way that the 

 weight of the cylinder and its frame keeps the valve closed; at ft, there 

 is a friction buffer. 



'"Everything being ready, a small weight or messenger is sent down, 

 which on striking the clamp disengages the latter and also the cyliuder, 

 when messenger, clamp, and cyliuder descend by their own weight to 

 ft, with the valve open during the passage. When the cylinder frame 

 strikes the buffer at b, the valve is therefore closed, and it is kept closed 

 thereafter by the weight of the messenger, clamp, and cylinder. The 

 frictiou buffer, which is 4 inches long, may be regulated on board to give 

 as many feet of cushioning as desired.'" 



The following is a detailed description of the apparatus : 



NOMENCLATURE. 



A. Cylinder, copper. 



B. Frame, wrought iron. 



C. Flap or clapper valve. 

 D D. Levers. 



E. Pivot. 



F. Wire sieve (60 wires to the inch). 



G. Wire sieve (27 wires to the inch). 



H. Wire funnel or trap (27 wires to the inch). 

 I I. Loops on fairleaders. 

 J J. Rollers. 



K. Frame of friction clamp. 



L. Sliding chock. 

 M. Sliding chock. 



N. Adjusting screw. 



O. Sling. 



P. Eccentric tumhler. 



Q. Frame of friction buffer. 



R. Sliding chock. 



S. Sliding chock. 



T. Adjusting screw. 



U. Compression spring. 



V. Regulating screw. 



W. Key. 



X. Messenger, cast-iron. 



