DEEP-SEA EXPLOKATION. 
395 
an attempt to land it, cat a slit in the net and allow a portion of its contents to 
escape. The small trawl net swings over the rail without the aid of strap and tackle. 
To empty the trawl net, suspend it by the boom tackle, remove the mud bag, cast 
off the tail lashing, and allow the contents to run easily into the table sieve; Avash the 
mud from the net with a hose, still holding it over the sieve that the specimens may 
fall into it, then lower it on deck; secure the contents of the Aving nets by turning 
them inside out and rinsing them in a bucket of Avater; examine the trawl net, remove 
specimens that may adhere to it, re])air rents, and prepare it for the next cast. 
The mud in Avhich the specimens are imbedded is washed from the table sieve 
with a steam hose, Avithout nozzle, Avhich affords an ample tlow of water Avithont force 
enough to Injure the specimens. After they have been secured, the sieve should be 
thoroughly cleaned and the mud and water rinsed from the deck, in order to avoid 
the possibilty of mixing the hanls. A single specimen, even, out of place may throAv 
discredit on the operations of a day. 
The Blake deep-sea traAvl is designed for use in great depths. It is operated 
l)ractically the same as a beam traAvl, over which it has the following advantages: 
1. It lias a lead rope on each side, and is right side np whichever way it lands. It may turn 
on its way down or while it is dragging without affecting the haul. 
2. It may he lowered vertically until near the hottom, providing the pocket is properly lashed 
down and sufficient weight attached to tail of net to carry it down as rapidly as the frame will sink. 
3. The course may he changed to any extent while lowering or dragging, providing the rope is 
not slackened. 
The disadvantages compared with the beam trawl are: 
1. The small sweep of lead rope. 
2. A large volume of water rushes into the widely distended mouth iluring its ascent and injures 
the delicate specimens whenever they <are unprotected I>y a covering of hottom soil in the hag. The 
facility with which it is operated and its certainty of action commend it for deep-water work, how- 
ever, in spite of its faults. 
The recorder keeps a full record of the haul, making the following entries: 
1. The kind of trawl used. 
2. Time of paying out each 100 fathoms of dredge 
rope. 
3. Total length of dredge rope paid out. 
4. Course and distance trawl is dragged on hottom. 
5. Time the trawl is dragged. 
6. Time re<iuired to heave up each 100 fathoms of 
dredge rope. 
7. Load ill trawl net — heavy, ordinary, or light. 
8. General contents of the trawl net from his own 
observation, and such information as he can 
obtain from the naturalists. 
9. Any matter of intere.st connected with the 
haul, as striking an obstruction, trawl bury- 
ing in the hottom; loss or iujury to rope, 
trawl, or other apparatus. 
A haul of the dredge follows in case the trawl eucounters foul ground or it is 
desired to collect mollusca or annelids that burrow in the bottom soil. It is operated 
in the same general manner as the Blake deep-sea traAAd, and Avas formerly used 
instead of trawls for deep-sea work, but its scope is now confined to shoal Avater or 
moderate depths. The recorder keeps the same record as for a haul of the trawl. 
A haul of the tangles follows if the bottom is too foul for the successful operation 
of trawl or dredge. The tangles are the simplest and most easily manipulated of all 
the various forms of apparatus for submarine collecting; they can be lowered verti- 
cally, if desired, more rapidly eA^en than the dredge, and are expected to take their 
chances on the roughest bottom except they become locked under iirojecting rocks in 
such a manner that a reversal of direction is required to release them. A variety of 
forms are taken Avith the tangles, including starfish, sea-urchins, crinoids, corals, and 
even fishes of considerable size. The same record is kej)t as in trawling and dredging. 
