24 



THREE CRUISES OF THE " BLAE:E. 



had undergone but slight modifications. It consists of a rec- 

 tangidar frame with flattened sides, to which a bag of net- 

 ting is attached, this again being protected by a canvas bag. 



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Fig. 22.— "Blake" 

 Dredge Frame. 



Fig. 21. — Miiller's Dredge. (Thomson.) 



The dredging-rope is attached 

 to one of the wire arms fas- 

 tened to the short side of the 

 dredge-frame ; the other arm 

 is made fast to the first by 

 a stout marline, so that in case 

 the dredge fouls, the marline will give way, trip 

 the dredge, and not part the rope, which would 

 involve the loss of the dredge. The dredges 

 used in deep water are generally much larger and 

 heavier than those used from small sail-boats. 

 To prevent the crushing of delicate specimens 

 by the dragging of the bag over rough bottoms, a frame-work 

 (Fig. 22) has been added to the ordinary dredge ; this is cov- 

 ered with heavy canvas (Fig. 23), so that the bag with its con- 

 tents is relieved of the wear and tear which comes of draacino^ 

 it over the bottom ; the most delicate specimens are thus secured 

 uninjured. 



Fig. 2:1 

 Blake " Dredge. 



