may be found in such books as ' Three Cruises of the Blake,' by Alexan- 

 der Agassiz, and 'The Depths of the Sea/ by Sir Wyville Thompson. 

 These books may be consulted in almost any library. 



"One can hardly realize the difficulty attending the gathering of 

 these animals from such depths. Let us imagine that a dredge is dropped 

 from the top of the Masonic Temple in Chicago, a height of about two 

 hundred and seventy feet, and drawn along the street to catch such insects, 

 mollusks, and other invertebrate life as might be there. It is manifest 

 that only a small percentage of the fauna would be represented by such 

 a method. The depth mentioned is only forty-five fathoms, and if there 

 is difficulty in securing a representative collection for this moderate dis- 

 tance, what must be the almost insurmountable difficulties when that 

 distance is magnified fifty times ! Yet with all these difficulties the 

 animals of the abysses of the sea are being collected and classified. 



" These animals are being obtained by means of 

 a large dredge, of which you will find a description in 

 the books mentioned above. This work is, of course, 

 beyond the reach of any save a government or a very 

 wealthy person. A little dredging may be done by 

 even a novice, along the shore in waters ranging 

 from two or three to ten fathoms. The dredge 

 should be about two feet wide at the mouth, and 

 of the shape indicated by this drawing which I have 

 roughly made. The netting should be stout, and 

 protected by canvas flaps on each side to prevent 

 it from being torn. A stout manila rope about ten 

 feet long and three-fourths of an inch in diameter 

 should be permanently attached to the ring of one 

 arm of the dredge. The ring of the other arm 

 should be fastened to the ring of this arm by ordinary 

 twine. This may seem somewhat ridiculous at first, 

 but it is really quite important, for should the dredge 

 become caught by a large boulder or other obstruc- 

 tion, a strong pull will break the twine, and the two arms will swing 

 apart, allowing the dredge to be brought to the surface. If both arms 

 were securely fastened by the heavy rope, the dredge could not be freed 

 from the obstruction, and would be lost. The end of the ten-foot rope is 

 made into a stout loop, to which the long dredge rope is knotted. 



" If a rowboat is used, it should be large and heavy and rowed 

 by two men, each pulling a single oar. The person controlling the 

 dredge should sit in the stern, and between him and the rowers there should 



89 



A marine dredge 

 ready for use. Note the 

 manner of fastening 

 the two arms together 

 at A, so that they will 

 fall apart when an extra 

 strain is brought upon 

 them. 



