THE SHIP AND ITS EQUIPMENT 



35 



the investigation of the animal Hfe of the sea. The appHances Closing nets 

 for capturing animals at the bottom have undergone only slight aJewSrr'^' 

 alterations, whereas many different kinds of contrivances for 

 capturing the pelagic animals have been tried from time to 

 time, some of them being of real practical value. 



Chun has done more perhaps than any other naturalist in Chun and 

 the way of studying the vertical distribution of organisms. Jios^ngnet. 

 Together with Petersen he constructed a vertical net that could 



Fig. 15. — Nansen's Closing Net. 



16. — Chun's Net. (From Chun.) 



be let down closed, then opened, and finally closed again, so 

 as to catch the smaller organisms existing in a specified layer 

 of water, say between 400 and 200 metres beneath the surface. 

 Subsequently other closing nets were constructed on the 

 principle of this invention. Fig. 15 shows Nansen's closing Nansen 

 net open (a), and shut (d), the construction of the net itself ^^i^^^^g 

 and the closing mechanism being easily understood from the 

 illustrations. It is extremely simple and reliable, and we have 

 tested it in various ways during the cruises of the " Michael 



