64 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



Fig. 5. The dredge, as modified by Captain Sigsbee and Mr. Jacobi, in use 

 on the " Blake." The end of the dredge-bag was, as in the trawl, securely- 

 tied and fastened to the frame, to prevent its reversing. A trap, as in 

 an ordinary lobster pot, also prevented the washing out of many specimens 

 when the dredge came to the surface. The opening of this dredge was 

 4 ft. by 12 inches. 



Fig. 6. Section of Fig. 3. 



Fig. 7. In a sketch of the double trawl (10 ft. beam) used on board the 

 " Blake," the end of the trawl was securely tied so as to gain easy access to the 

 specimens accumulated at the end of the trawl. A set of cork floats suspended 

 in the middle of the trawl kept one side of the net well up from the bottom. 

 The trawl liad the usual trap. To the end of the trawl a common wooden 

 detacher, similar to that of a deep-sea sounding machine, was fastened for 

 detaching the shot with which it was usually weighted. At great depths 

 weights were attached to the runners. The trawl was strengthened by ropes 

 forming a large network to support it. 



I hope, in my next letter, to be able to give detailed drawings of 

 Captain Sigsbee's water-bottle and of his modifications of Sir William 

 Thomson's sounding-machine. 



