THE SHIP AND ITS EQUIPMENT 



47 



fish almost as well as the trawl itself. The cylindrical fore part 

 is largely responsible for this, as it retains within its walls the 

 animals that do not pass immediately into the after part, which, 

 owing to its great length, lets the water filter easily through. 

 One great advantage of these tow-nets is that they can be 

 lowered very rapidly when used as vertical nets. They then 



Fig. 30. — Large Vertical Closing Net. 



assume the shape depicted on the left in Fig. 29. The net in 

 the foremost portion of the cylinder is the only part that offers 

 any resistance, and it too is wide meshed, so that the water 

 easily passes through it ; the rest descends like a thick rope. 

 They can also be used as closing nets, and we have actually 

 employed in that capacity nets J, f , and i metre in diameter at 

 the entrance. 



We further constructed two large closing nets, 3 metres in 



