DEEP-SEA EXPLORATION. 
355 
one. The long tails are nsed on the runners in order that they may be released from 
their weight as soon as the trawl frame reaches bottom, where its tendency is to sink 
into the mud or ooze, and the short lashing at the end of the net is to prevent the 
weigiit from interfering with the mud bag. The float q is seized to the back of the 
net a little forward of the lead rope, and its purpose is to enlarge its entrance. 
The bridle is of 3-inch manila rope, 14 fathoms in length, and is Htted by turning a 
thimble into the bight, taking an overhand knot in both legs about 8 feet from the 
thimble, and splicing eyes in the ends, longer or shorter, as retpiired to make the legs 
hang a little slack when the net is loaded. 
The bridle stoq)s are of marline; they are used to seize the bridle legs to the eyebolts 
in the forward end of the runners; the number of turns is determined by experiment, 
the intention being that they shall break before a dangerous strain is put upon the 
dredge rope. A Duckham weighing machine is used on board the Albatross for 
determining the strength of the stops, and with the ordinary (piality of marline nine 
turns break with a load of 5,000 to 0,000 pounds, the limit allowed with new roiie. 
The bridle and bridle stops are practically the same for all of the trawls described 
except the Tanner No. 3, the only dift'erence being in the length of the legs; those for 
the beam trawl and the Tanner No. 1 are the same; the Blake trawl requires them 
about 3 feet longer, and the Tanner No. 2 as much shorter. 
Traud weights are attached to frame and net in sufflcient numbers to insure the 
prompt sinking of the trawl. They are square in cross section, 11 inches in length, 4 
inches in diameter at the base, and 3 at the upper end, which is flattened and iiierced 
with a hole for the tail. Manila rope, 15-thread, and 1 fathom in length, is used for 
the purpose. The apparently awkward shape was adopted to prevent the weights 
from rolling about the decks in heavy weather. They will stand upright ordinarily, 
and will not roll under any circumstances. They weigh from 28 to 30 pounds. 
Tail lashings for trawl nets are of 15-thread manila rope, about 3 fathoms in 
length. Soft, pliable rope is preferred. 
Floats for trawl nets were formerly made of cork, which answered the purpose 
in moderate depths, but became water-logged and worthless under the pressures 
encountered in deep-sea work; hence Norwegian glass floats were introduced. They 
are spherical in form, 6 to 7 inches in diameter, thickness of glass to f inch, and they 
are inclosed within hand-made netting, having small eyes worked on opposite sides, 
through which their lashings are secured. Floats are attached to the upper part of 
the trawl net in rear of the beam, and it is their function to keeii it elevated as 
much as possible, thus increasing the area of the opening or mouth. They have, with 
few exceptions, withstood the pressure even in depths approaching 3,000 fathoms, 
and they are seldom broken, owing to their secure position on the trawl net and the 
protection given them by their covering of netting. 
Wing nets were introduced by Capt. H. 0. Chester and first used on board the 
Fish Hawk in 1880. Nets of various forms have been used for intermediate collecting, 
but they were attached to the dredge rope. The present form is a modification of the 
Chester net, and was devised by the writer in 1884, since when they have been in 
constant use on board the Albatross. They are made of cheese-cloth in the following 
manner : The material is laid on deck and folded once, a jiattern placed upon it, and 
the two halves cut from the piece at the same time; the side seams are then sewed 
uj), the ends hemmed, and one extremity turned inward over a galvanized iron ring. 
