28 
THREE CRUISES OF THE “ BLAKE.” 
better than a trawl, which, when moved rapidly over the ground, 
at the rate sometimes of two to two and a half miles an hour, 
invariably brought up a fine harvest of fishes and crustacea, in 
addition to the usual contents of the sedentary and more slug- 
gish forms. Although the deep-sea tow-net was used several 
times, we never brought up any of the so-called deep-sea sipho- 
nophores of Studer, even in localities where they came up on 
the wire rope. 
All dredging expeditions previous to the first cruise of the 
“Blake” had used best selected hemp rope for dredging. 
The objections, already mentioned, to the use of hemp rope, 
speaking of sounding, apply with even greater force to its use 
in dredging. The necessity of loading down the trawl with 
weights, or of making the trawl itself enormously heavy, in 
"i 
H ni) 
Fig. 27. — Comparative Size of Dredging-Ropes. · ( Sigsbee.) 
order to sink a heavy rope strong enough to bring back not 
only its own weight, but that of the trawl and its contents and 
of the weights usually sent down with the dredge, — all this 
increased the danger that the rope might part at great depths. 
The rope also, after short use in deep water, becomes very brit- 
tle from the great pressure to which 1t has been subjected, and 
unfit to bear any considerable strain. My familiarity with the 
successful use of very long steel ropes for mining purposes nat- 
urally suggested their adaptation to the new purpose of deep- 
sea work. The results anticipated have been fully realized, 
and the gains in space (Fig. 27), in time,” in safety and facility 
! 'The rope used for deep dredging is made by the * Blake," in fifteen hun- 
usually two and one half inches in cir- 
cumference. It weighs two pounds to 
the fathom, breaking strain about two 
tons; so that the weight of rope, trawl, 
and. contents is often more than half the 
breaking strain. 
2 A haul of the trawl was frequently 
dred fathoms, in less than two hours 
and three quarters, dragging on the bot- 
tom twenty-five minutes, The trawl can 
safely be lowered at the rate of one hun- 
dred fathoms in four minutes, and be 
reeled in at the same or even a more 
rapid rate. 
