DEEP-SEA EXPLORATION. 357 
A float of cork is vised ujion the top of the net to extend its moutli. The pocket 
is omitted to save weight. 
THE BLAKE DEEP-SEA TRAWL. 
The Blake Trawl (cut G4) is designed for deep-sea work, as its name implies, 
and is not well adapted for use on the hard, sandy bottom usually encounterevl in 
shoal water, owing to the limited height of the beam and restricted sweep of the lead 
roive. It is practically a double beam trawl with central beams, and lead ropes on both 
sides, so that it is a matter of indilference how it lands. 
This is a. great advantage which all deep-sea explorers will appreciate after operat- 
ing the beam trawl, the successful use of which depends upon its being landed on the 
bottom right side up, a feat which the expert will accomplish with rare exceptions, 
even in the greatest depths; but the inexperienced explorer will frequently discover, to 
his chagrin, that it has been dragging bottom side up and the haul is a practical failure 
in consequence. The Blake trawl admits of a change of course in any direction and 
to any extent while it is dragging on the bottom, ivroviding the dredge rope is not 
slackened sufficiently to allow it to kink. 
The disadvantage in the use of this trawl is the greater wash through its widely 
distended mouth during the ascent, which is injurious to the more delicate forms, but 
this evil is largely compensated by the cheese-cloth lining and the protecting folds of 
the net. Its dimensions are as follows : 
Beams, front ami rear: Material, iron pipe; length, 10 feet; iliameter outside, 2i- inches ; thickness 
of metal, inch ; holes in ends, f inch square. 
Runners: Material, fiat har iron; width, 3 inches; tliiclvne.ss, I- inch; length, 4 feet d inches; 
height, 2 feet; holes for beams, f inch square; holes for lead rope, 1 inch diameter. 
Bolts: Material, iron; size, f inch square, with thread and nut; length, 31 inches; rear with flat 
heads ; front with eyes for bridle. 
Weight of frame, 200 pounds. 
Net; Material, cotton, barked, 30-thread; size of me.sh, square, 11 inch; length, 20 feet. 
Pocket: Material, cotton, barked, 21-thread; size of mesh, square, 1 inch; length, G feet. 
.Jacket: Material, cotton, barked, 16-thread; size of mesh, squ.are, finch; length, G feet; lining, 
cheese-cloth. 
Rope, manila; lead and leech ro]>es; circumference, 2 in( hes; bridle, 3 inches. 
Float, Norwegian glass globe; diameter, 6 inches. 
Tlie space between the front and rear beams, avid sometimes tlie inner surfaces 
of the ruuiiers, are filled with netting tiglitly laced from side to side to increase the 
lead into the mouth of the net; the former is of undoubted utility, as the upper lead 
rope sags nearly to the level of the rear beam, thus reducing the area of the opening 
nearly one-half. 
