ii8 DISCOVERY REPORTS 



with the stop and heavy closing mechanism attached inboard, is now Hfted out of the 

 fair-lead with a snatch-block and tackle from the poop derrick plumbed directly over- 

 head, and the gear is passed clear over the side and held fast about a foot abaft the rail. 

 The wire is then slacked back into the fair-lead. In passing the gear over the rail the 

 snatch-block is placed in front of the large mechanism, from which it must be backed 

 well clear by means of a whip to the rigging, otherwise by riding down the warp it will 

 come in contact with the apparatus and bring about a premature release. The derrick is 

 now swung amidships and the frame, suspended from a slip-hook provided with a 

 tripping line, is hoisted until it clears the rail when the bucket and net are put over 

 and allowed to drift astern. When all is clear the frame is lowered to the water's edge 

 and tripped, preferably when about three parts submerged to avoid an unnecessary jerk 

 on the release. It helps greatly when shooting if the throttling wire and all six bridles 

 be gathered together into a single bundle and the whole stopped off with a few turns of 

 sail twine. This procedure is a safeguard against mishap as the bridles and wire, if 

 flying about loose, are apt to foul the release while the frame is being lowered into the 

 water. The stops, of course, part readily as soon as the strain comes on the bridles. 



Throughout this operation the ship is kept moving very slowly ahead, at little more 

 than half a knot, but as soon as the net has entered the water and is streaming well away 

 speed is increased considerably and the warp allowed to run out as rapidly as possible. 

 In a deep haul requiring 4000 or 5000 m. of wire the first 2000 m. as a rule is paid away 

 at from 60 to 80 m. per min., the ship making from 2 to 3 knots. The remainder, 

 however, is run out at an ever decreasing rate as the increasing load over the stern 

 automatically retards the forward speed of the ship. Particular care must be taken in 

 paying out the last 1000 and the last 500 m., for if then allowed to run out too fast, the 

 wire, by virtue of its greatly increased total weight, may over-run the net, and, becoming 

 slack, may kink or fly into a bight round the release. In shallow water work, when the 

 time occupied in paying out is merely a matter of minutes, nets shot open catch next to 

 nothing on the way down. Deep nets on the other hand, taking anything from an hour 

 to an hour and a half to reach their required level, are naturally far more liable to error 

 through fishing on the way out. It is therefore of the greatest importance that in 

 practice they be paid away at a rate which as nearly as possible is just a fraction under 

 that at which the ship is travelling. 



When the wire is all out and the necessary reduction in the ship's forward speed has 

 been made, hauling begins and is continued without a break to the surface, the mes- 

 senger, as in vertical hauling, being despatched in time to meet and close the ascending 

 net at the moment when the metre-recording dial shows that the required amount of 

 warp has come in. The winch may be stopped for a few seconds while the messenger is 

 being attached to the wire, but it is better not to do so, for even a momentary slackening 

 of the fishing speed might be enough to allow the more active individuals in the catch 

 to escape. In timing the despatch of the messenger allowance is made for its own speed 

 and for the rate at which the net is approaching from below. At the steep warp angles 

 employed in rapid oblique fishing the 22 lb. messenger in use travels about 2000 m. 



