34 THREE CRUISES OF THE “ BLAKE.” 
dredge was over the side, and everything ready for lowering, 
the reeling-engine was reversed slowly until the trawl was well 
started, when the lowering could be done somewhat more rap- 
idly; and as soon as sufficient wire had been payed out, so 
that its weight and that of the trawl were great enough to 
overcome the resistance to the descent of the rope, then stain 
was shut off and the wire was managed entirely by the fric- 
tion-brake. During the lowering, iid steamer was very slowly 
backed, and as soon as the trawl was well planted she was 
backed more rapidly, until, according to the soundings, an ad- 
ditional amount of rope equal to from a third to twice the 
depth had been payed out. Then, when the wire rope was 
well fast, the steamer was backed at the rate of a mile and a 
half to three miles an hour, according to the nature of the 
bottom, dragging the trawl for a length of time varying from 
ten to twenty minutes. In hauling up, the winding-engine was 
again brought into requisition, great care being taken, when 
the trawl or dredge broke ground, that the movement should 
be slow at first when the strain of the trawl and its load came 
upon the wire rope. 
A new crew requires a little practice to become familiar with 
the working of the machinery, and in our first attempt off Ha- 
vana we came to grief by paying out the dredge-rope too fast. 
This produced a tangle of about two hundred fathoms of steel 
wire, the cause of which was easily explained when we saw the 
hopeless result; but it also taught us the speed at which we 
should lower and the proper manner of handling the vessel dur- 
ing the operation, so that the accident was altogether a most 
fortunate one for the future progress of the work. 
Intimately conneeted with the fauna of great depths is the 
pelagic fauna. The innumerable marine animals which always 
live at or near the surface, either during their whole life or 
merely during their earlier stages of existence, play an impor- 
tant part in the economy of the deep-water fauna. The surface 
of the ocean on calm days swarms with pelagic mollusks, crus- 
tacea, echinoderms, jelly-fish, and the like, either adults or em- 
bryos, associated with foraminifera and sponges. The surface 
animals are collected by means of a hand-net (Fig. 31) made of 
