GENERAL INTRODUCTION TO THE ZOOLOGICAL REPORTS. 



13 



The iron framework of our largest dredge was 5 feet in length, and 1 foot 3 inches in 

 breadth — its weight being 137 lbs. ; the next size, which was made much stronger, was 

 4 feet in length, 9 inches in breadth, and weighed 259 lbs. ; and the smallest was 3 feet 

 iu length, 1 foot in breadth, and weighed 85 lbs. The smallest size was commonly used 

 for great depths ; with it we obtained a successful haul in 3875 fathoms. 



The ship was provided with thirty-four dredges, eleven of which were expended, 



Fia. 9.— The Deep-Sea TrawL 



The Deep-Sea Traiol. — Fig. 5 represents the deep-sea trawl, which we used almost 

 constantly during the latter part of the voyage. A conical bag, 20 feet in length, is 

 suspended by one side to a beam of hard wood, 16 to 20 feet long, by half a dozen straps. 

 The other side of the mouth of the net hangs loose, and is weighted with close-set rolls of 

 thick sheet lead to drag along the bottom. Two iron runners, like the runners of a 



