254 THE DEPTHS OF THE SEA. [CHAP. VI. 
fathoms from the dredge, and the dredge itself. The 
vessel now steams slowly to windward, occupying 
successively the positions £, F, G, and H. The weight, 
to which the water offers but little resistance, sinks 
from w to w’, and the dredge and bag more slowly 
from D to B. The vessel is now allowed to drift back 
before the wind from H towards c. The tension of 
the motion of the vessel, instead of acting immediately 
on the dredge, now drags forward the weight w’, 
so that the dredging is carried on from the weight 
and not directly from the vessel. The dredge is 
thus quietly pulled along with its lip scraping the 
bottom in the attitude which it assumes from the 
centre of weight of its iron frame and arms. If, 
on the other hand, the weights were hung close 
to the dredge, and the dredge were dragged directly 
from the vessel, owing to the great weight and 
spring of the rope the arms would be continually 
lifted up and the lip of the dredge prevented from 
scraping. In very deep dredging this operation 
of steaming up to windward until the dredge-rope 
is nearly perpendicular, after drifting for half an 
hour or so to leeward, is usually repeated three or 
four times. 
At 8.50 p.m. we began to haul in, and the ‘ Aunt 
Sallies’ to fill again. The donkey-engine delivered 
the rope at the rate of rather more than a foot per 
second, without a single check. A few minutes 
before 1 a.m. the weights appeared, and a little after 
one in the morning, eight hours after it was cast 
over, the dredge was safely hauled on deck, having 
in the interval accomplished a journey of upwards 
of eight statute miles. The dredge contained 13 ewt. 
