EQUIPMENT. 



25 



While using, especially on muddy bottom, the dredge as for- 

 merly made, with a frame having a bevelled edge, we experi- 

 enced great annoyance at first from the amount of mud brought 

 up by it. When the dredge was dropped in soft ooze, it evi- 

 dently sank deeply in it and filled at once ; and since the viscid 

 mud did not wash out easily, it was even difiicult to sift it on 

 deck. To obviate this defect, we stopped a piece of two-and-a- 

 half -inch rope below the dredge-frame to raise the lips and pre- 

 vent it from cutting into the mud. This worked admirably, 

 and after that our dredges always came up bringing less mud 

 and a larger supply of specimens. We subsequently made our 

 dredges with a flat frame, obviating completely the defects in 

 the old-fashioned dredges.^ 



Attached to the end of the dredge-frame is a long iron bar 



to which are fastened 

 large swabs. These 

 huge rope tails trail be- 

 hind the dredge, and in 

 them become entangled 

 all sorts of starfish, sea- 

 urchins, crabs, corals, 

 sea-fans, sponges, and 

 even fishes w hich d o 

 not readily find their 

 way into the dredge. 

 When the bottom is 

 very rough or rocky, 

 or it is of uneven coral, 

 the bar and tangles 

 alone are frequently 

 used. (Fig. 24.) For this 

 sort of bottom, where 

 there is always danger 

 that either a dredge or 

 Fig. 24. — Bar and Tangles. a trawl maybe Carried 



1 A dredge is used among natives of in action in one of his lectures on Deep- 

 the Philippines and Japan. Mr. Mose- Sea Dredging, 

 ley has given a sketch of such a dredge 



