174 ALEXANDER AGASSIZ 



vessel like the Blake (350 tons), I could have under- 

 taken deep-sea work continuously, and been able to 

 stow away the length of 2§ and 3 inch rope needed for 

 my work. In place of having decks entirely choked with 

 rope, we had only two reels of steel rope 1J inches in 

 circumference, each of 3000 fathoms, the whole space 

 occupied being less than 5x5x4 feet for cast reel; 

 the reels themselves were used by means of friction 

 brake to lower the dredge and trawls with, and we 

 hoisted up by an intermediate donkey engine. Now in 

 dredging, we gained immensely again in time, the speed 

 of lowering the dredge and trawls and bringing them 

 up again being fully as great as that attained in hoist- 

 ing from stopes in mines. In fact it was my experience 

 with mining and use of steel ropes which first suggested 

 to me the idea of using it for dredging. We have thus 

 far made no less than over 50 casts of dredge and trawl 

 from 300 fathoms to 1920 fathoms, and have expe- 

 rienced no trouble of any kind and thus far have lost 

 only 200 fathoms 1 of steel rope ! although we have lost 

 plenty of dredges and trawls. The strength of this steel 

 rope was 8600 pounds breaking strain. The greater 

 weight gave us the great advantage of not being obliged 

 to send weights down to act as fulcrums 2 — a great sav- 

 ing of time. Now in Challenger in deep water the best 

 part of a day was usually occupied in making one haul 

 in over 1500 fathoms. 



1 This was done at the first cast, and was the only rope lost on this 

 cruise. The amount of rope lost on the other cruises was trifling, and at 

 the end of three years most of the rope was still perfectly serviceable. 

 On the cruise of the Challenger over fifty-eight miles of hemp rope was 

 lost or worn out. 



2 With hemp rope, in order to sink the dredge, not only did it have to 

 be weighted, but it was also necessary to attach heavy weights on the rope 

 some distance ahead of the dredge. 



