. Fig. I. Plan of 4I m. net showing principal measurements and main structural features (after Kemp and Hardy). A, cylindrical non-catching part of i| in. mesh netting, 50 ft. in circumference. BCD, conical catching part tapering to a circumference of 3 ft. at e, with meshing as follows: B, | in., C, 7 mm., D, 7 mm., Hned at the cod-end with finer 4 mm. material, e, canvas cylinder to slip over bucket; /, canvas band; g, longitudinal webbing supports; /;, bridles; r, net ring, 450 mm. in diameter, 50 ft. in circumference. The curious poverty of material in the closing net gave rise to the some
. Fig. I. Plan of 4I m. net showing principal measurements and main structural features (after Kemp and Hardy). A, cylindrical non-catching part of i| in. mesh netting, 50 ft. in circumference. BCD, conical catching part tapering to a circumference of 3 ft. at e, with meshing as follows: B, | in., C, 7 mm., D, 7 mm., Hned at the cod-end with finer 4 mm. material, e, canvas cylinder to slip over bucket; /, canvas band; g, longitudinal webbing supports; /;, bridles; r, net ring, 450 mm. in diameter, 50 ft. in circumference. The curious poverty of material in the closing net gave rise to the somewhat dis- turbing view that a large proportion, perhaps the majority, of the animals captured in a big open net fished horizontally might be taken not from the restricted horizon at which the net was fishing, but during its ascent towards the surface when the speed of towing as a rule is augmented by hauling. In other words it began to be suspected that the N 450, big as it was, was not being towed fast enough to capture the strong and actively-moving species for which it was designed—it seemed exceedingly likely in fact that during the horizontal tow all but the weakest were contriving to make their escape from the net, if they were not indeed eluding it altogether. It was for this reason that in later experiments the old method of slow horizontal fishing was abandoned and the faster method of the oblique tow, which for some time had been employed to advantage with smaller nets, took its place. The poor condition of the material is not surprising, for so large an apparatus when closed on the Nansen principle would appear to behave as Kemp has put it " like an ill- 1 At a speed which is stated to have been about 2 knots. See, however, p. 115.
Size: 4787px × 1044px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
