48 
PACIFIC SCIENCE, VoL XII, January, 1958 
Figs. 1-3. (1) General diagram of catcher, rigged as for vertical towing. 
(2) Nosepiece, mouth chamber, and valve chamber showing the relationships of the parts to each other, to the 
forward end of the body and the net. Note that the valve is closed. 
(3) Tailpiece showing the after end of the net, its frame, the depth-flow meter and the vertical-wire bracket. 
Note: Figures 2 and 3 are to same scale and are X 2, Figure 1; for legends, see Table 1. 
tail is removable and the net then can be 
freely withdrawn towards the rear. 
Nose, body, and tail (including the fins) 
are manufactured from Crystic 191, an epoxy 
resin, with fibreglass reinforcement. These 
materials have important advantages. To- 
gether, they are tough, light in weight (spec- 
ific gravity 1.3 approx.) and non-corrodible 
in seawater. Absorption of water is very low 
and they have proven dimensionally stable in 
the catcher under diverse conditions of towing 
and handling. They have been subjected to 
pressure at 1500 m. without any indication of 
delaminating or pulverizing in spite of small 
entrapped bubbles of air. 
The opening of the mouth is 9 in. in 
diameter and leads into the mouth chamber 
(Figs. 1, 2, 4, b). Behind, and partly con- 
tained by the nosepiece, is a separate valve 
chamber (2, e). Castings forming the mouth 
and valve chambers are mounted on a cast 
bronze ring (Figs. 1, 2, 4, a"). The internal 
surfaces of the chambers and ring are con- 
tinuous, and they curve inwardly towards the 
rear, where they form a circular opening of 
IVi in. diameter. The inner surface of this acts 
as a bearer to the outer face of the valve 
(2, 4, S). 
The valve (Figs. 2, 4, c) is a short, open- 
ended cylinder, of 714 in. internal diameter. 
