37 



Al' Trawls haivde vi 2 Slags, begge leverede at' Dr. 

 .T. Hearder iV Smi i Plymouth, nemlig Otter-Trawl og 

 Bom-Trawl, 



< M' Trawls we had two kinds, viz. the Ottei'-trawl and 

 the Beam-trawl, both furnished by Dr. f. Hearder å Smi 

 of Plymouth. 



Fig. is. 



Otter-Trawlen (Fig. 18) er nærmest et Fiskeapparat 

 og ikke særdeles meget skikket til zoologisk Brug: Det 

 bestaar at' et Net, der er aabent foran og bagtil snevrer 

 sig sammen til en Spids. Til Netmundingen er fastgjort 

 2 Ottere eller firkantede . Træplader, 0. ra 63 (2 Fod) høje, 

 hvis Underkanter er belastede med Jernmejer. Enderne 

 af Hanefoden, der forbinder Skrabetouget med Trawlen, 

 er fastgjort til Stropper paa Indersiden af disse Ottere. 

 saaledes at de muler Farten ved Vandtrykket skjærer ud til 

 hver Side. Overkanten af Netmundingen holdes oppe ved 

 Korkstykker, medens Underkanten er belastet med Blystyk- 

 ker. Netmundingen er 7 m .o (24 Fod) bred mellem Otterne, 

 og Posens hele Længde er 6. m 3 (20 Fod). 



Naar Otterne skal komme i Stilling, maa dette Ap- 

 parat gives saa stor Fart gjennem Våndet, at det paa 

 Grand af Tougets Visning paa større Dybder er udsat for 

 at løftes fra Bunden. 



The Otter-trawl (Fig. 18) is properly a fishermans 

 apparatus, and not verywell adapted for scientific purposes. 

 It consists of a long conical bag of cord-netting. to the 

 mouth of which are attached two -otters." or quadrangular 

 pieces of wood, 2 feet square. each weighted on the lower 

 part with an iron runner. The ends of the crow-foot con- 

 necting the trawl with the dredge-rope are secured to straps 

 on the inner side of the otters, in such manner as will 

 cause the latter, when in motion, to sheer out. or diverge, 

 from the action of the water. The top side of the mouth 

 of the net is kept in position by pieces of cork. the under 

 side being weighted with rolls of sheet-lead. The lengtb. 

 of the trawl-bag is 20 feet, and its width at the mouth. 

 measured between the otters. 24 feet. 



To give the otters the right position. the trawl must 

 move through the water with a rapidity that. by reason 

 of the oblique direction of the dredge-rope. will easily 

 cause the apparatus to he lifted from the bottom. 



Fig. 19. 



