CHAP, vi.] DEEP-SEA DREDGING. 249 



CAvts. an approximation at all events to the strain 

 on the rope. 



A second derrick, nearly equally strong, was rigged 

 over the stern, and we dredged sometimes from one 

 and sometimes from the other. The stern derrick was, 

 however, principally used for sounding ; the letting- 

 go board, &c., being fitted up in connection with it. 

 We had an excellent arrangement for stowing the 

 dredge-rope in the ' Porcupine ;' an arrangement 

 which made its manipulation singularly easy, not- 

 withstanding its great weight about 5,500 Ibs. A row 

 of about twenty great iron pins, about two and a half 

 feet in length, projected over one side of the quarter- 

 deck, rising obliquely from the top of the bulwark. 

 Each of these held a coil of from two to three hun- 

 dred fathoms, and the rope was coiled continuously 

 along the whole row (Fig. 46). When the dredge 

 was going down, the rope was taken rapidly by the 

 men from these pins ' Aunt Sallies' we called them, 

 from their ending over the deck in smooth white 

 balls in succession, beginning with the one nearest 

 the dredging derrick ; and in hauling up, a relay of 

 men carried the rope along from the surging drum 

 of the donkey-engine and laid it in coils on the pins 

 in inverse order. Thus, in letting go, the rope 

 passed to the block of the derrick directly from the 

 'Aunt Sallies;' in hauling up, it passed from the 

 block to the surging drum of the donkey-engine, 

 from which it was taken by the men and coiled on 

 the ' Aunt Sallies.' 



The length of the dredge-rope was 3,000 fathoms, 

 nearly three and a half statute miles. Of this, 2,000 

 fathoms were 'hawser-laid,' of the best Russian 



