. Discovery reports. Discovery (Ship); Scientific expeditions. 186 DISCOVERY REPORTS. Fig. II. Fine-meshed netting used in tow-net construction. Nat. size, a, 7 mm. mesh; b, 4 mm. mesh. a circumference of 22 ft. to 2 ft. 3 in., where it joins the canvas cyHnder, 2 ft. long, for attachment to the bucket. The front section, B, 61 ft. long, is of 7 mm. mesh (knot to knot) netting^ (Fig. 11 a), and C is 13 ft. long, of 4 mm. mesh netting^ (Fig. II b). As in the N 100 there are three longitudinal ropes, and in addition transverse ropes passing round the net, one between the sec- tions B and C and o
. Discovery reports. Discovery (Ship); Scientific expeditions. 186 DISCOVERY REPORTS. Fig. II. Fine-meshed netting used in tow-net construction. Nat. size, a, 7 mm. mesh; b, 4 mm. mesh. a circumference of 22 ft. to 2 ft. 3 in., where it joins the canvas cyHnder, 2 ft. long, for attachment to the bucket. The front section, B, 61 ft. long, is of 7 mm. mesh (knot to knot) netting^ (Fig. 11 a), and C is 13 ft. long, of 4 mm. mesh netting^ (Fig. II b). As in the N 100 there are three longitudinal ropes, and in addition transverse ropes passing round the net, one between the sec- tions B and C and one in the middle of C These were originally made of log line to prevent any tendency to twist and so bunch up the net; but it was found not to be strong enough and was replaced by ordinary manila rope of 2 in. circumference. The bucket, like the others, is described on page 191. The closing rope is similar to that of the N 100, but 40 ft. long, 2| in. in circumference and fitted with a large lignum-vitae bull's-eye. In practice this net was not used a great deal. When the larger, rarer and more active pelagic organisms were required the N 450, next to be described, which has an opening over five times in area that of the N 200, was used whenever possible. For collecting large quantities of the smaller forms the TYF was found to be more efficient. N 450. This net, with an opening of 4I m. diameter, is, we believe, the largest tow- net yet fished. Its function, as already indicated, is to capture the larger and more active pelagic animals, particularly the deep-sea forms such as medusae, Crustacea, cephalopods and fish. It was feared by some that the difficulties in handling so large a net, especially from a vessel encumbered with much rigging, might prevent its frequent use. These fears, however, proved to be groundless. That the resistance in towing so large a frame, and one stout enough to retain its shape out of water, should be reduced to a minimum was here a matter of great
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