Vestenfor Linien mellem Tromsø og Spidsbergen og 

 ■vestenfor samt nordenfor denne styrter derimod Bunden 

 sig ned til et stort Dyb, der midt imellem Spidsbergen* og 

 Grønland maaler 2650 Favne, en Dybde, der rivaliserer 

 med selve Atlanterhavets. Fra den nordlige Side af Bas- 

 sinet haves ingen Ledninger; kun ved man, at den vul- 

 kanske Jan Mayen styrter sig meget brat ned i Havet. 

 Heller ikke ved man. hverken hvorledes Bankerne paa 

 Islands Vestkyst eller Flakket mellem Island og Færøerne 

 gaa over til Ishavsdybet. Forholdene mellem Færøerne og 

 Skotland ere derimod nøie undersøgte af •'Porcupine"-Ex- 

 peditionen i 1869. Her gaar fra Ishavet en smal Bende 

 paa 600 Favnes Dyb ned i Atlanterhavet. Denne Bende 

 sn mt den formodentlig dybe Bende mellem Island og Grøn- 

 land synes at være de eneste Communications veje i Dybet 

 mellem Atlanterhavet og vort Ishav. Paa den norske Side 

 stnekker Kundskaben om Havbuudens Form sig saagodtsom 

 ikke udenfor de af .Fiskerne besøgte og af -HansteenVEx- 

 peditionerne oploddede Banker. Kun paa et eneste Sted. 

 ved Storeggen, have disse Lodninger antruffet en rask 

 Heldning af Bunden ud mod det store Hav-Bassin. Ellers 

 ere vi totalt uvidende om, paa hvilken Maade vor Kysts 

 Banker gaa over i Ishavsdybet. om det sker brat, eller 

 langsomt, om det sker nær Kysten eller om det først tinder 

 Sted langt ude i Søen. Kundskaben ■ om dette Punkt ei- 

 det netop, som vi maa anse det for et Hovedpunkt at 

 vinde. 



Med Hensyn til Temperaturen i det her omtalte Strøg 

 af Havet er vor Kundskab iudskrænket omtrent til de 

 samme Localiteter, som de hvor Dybdeforboldene ere under- 

 søgte. Temperaturniaalingerne fra vor Kyst vise, at vore 

 Banker og vore F jordes tildels store Dyb dækkes af Vand, 

 hvis forholdsvis høje Varmegrad viser ben til Atlanterhavet 

 som dets Udspring. Intetsteds langs Norges Kyst er der 

 paa Bankerne eller Fjordenes Bund fundet Kuldegrader. 

 Saadanne ere derimod fundne ikke alene saavel i Overfladen 

 som i Dybet ude i Havbassinets centrale Del og henimod 

 dets vestlige Band. men ogsaa i den dybe Bende mellem 

 Færøerne og Shetland allerede i 300 Favnes Dyb. 



Hvor langt vi maa gaa ud i Havet vestenfor Norge foråt 

 trette paa iskoldt Vand paa Bunden, derom staa vi aldeles 

 blottet tov Kundskab. Her staa vi atter ved et Hovedpunkt, 

 thi denne Græhdse mellem det vanne Atlanterhavsvand og 

 det iskolde Polarvand maa, efter det hvad der kan sluttes 

 af lignende Forhold, betegne ( Oandsen for de i Havet 

 levende Væseners forskjellige (Jdbredelse til den ene eller 

 til den anden Side. End ringere end vor Kundskab om 



'Dybde- og Var forhold er vor Kundskab om Strømforhold. 



der spiller en sa a stor Kolle i Dyrelivet, om Havvandets 

 Bestanddele. der er af lige Vigtighed, og om de jordmag- 

 netiske Forhold, der for Theorien som for Skibsfarten er 

 at sær Betydning. 



West of a line extending between Tromsø and Spitz- 

 bergen, as also west and north of the latter locality. the 

 bottom sinks to a great depth, reaching between Spitz- 

 bergeri and Greenland 2650 fathoms. and accordingly rival- 

 ling that of the Atlantic itself. Along the northern boun- 

 dary of the basin no soundings have as yet been tåken ; 

 all we know is. that the volcanic island ot Jan Mayen 

 plunges precipitately into the ocean. Nor is it yet known 

 how or where the banks on the west coast .of Iceland and 

 the flat between Iceland and the Færoe Islands, pass into 

 the depths of the Arctic Ocean. The section stretching be- 

 tween the Færoe Islands and Scotland, was, on the other 

 hand, carefully explored on the "Porcupine" Expeditibn, 

 in 1869. In this tract, a narrow channel, 600 fathoms 

 deep, extends from the Arctic Ocean to the Atlantic. This 

 channel, and probably too the deep channel between Ice- 

 land and Greenland. would appear to be the only highways 

 by which the depths of the Atlantic are connected with 

 those of the Arctic Ocean. Along the Norwegian coast. 

 what we know of the nature and contour of the bottom is 

 almost ^exclusively confined to that of the banks periodically 

 visited by Hshermen. and which of late years have been in- 

 vestigated on the Coast Survey expeditions with the "Han- 

 steen.'" In but one locality — off the Storeggen hank — 

 was the bottom found to sink rapidly down to the great 

 ocean-basin. With this exception. we are totally ignorant 

 as to how and where the hanks lving off the coast of this 

 country pass into the depths of the Atlantic, whether 

 gradually or precipitately. whether in close proximity to 

 the coast or possibly in mid-ocean. Now, the solution of 

 this problem appears to us of the greatest importance. 



As regards the temperature throughout the aforesaid 

 ocean-tract. it is known only for most of the localities in 

 which the depth has been measured. The comparatively 

 high temperature distinguishing the water on our. coastal 

 banks and in our fjords, many of which are of great depth. 

 points to the Atlantic Ocean as the source whence it is 

 derived. Nowhere along the coast of Norway, whether on 

 the banks or at the bottom of the deepest fjords, has 0° 

 been observed; but in the central . part of the ocean-basin, 

 and at its western margin, the temperature has been fouud 

 to be below zero. botb ,at the surface and in the depths: 

 nav. in the deep channel between the Shetlands and the 

 Færoe Islands 0° is reached at a depth of 300 fathoms. 



At what distance from the western shores of Norway 

 the glacial bottom-area commences. we are unnble to inter 

 from the data as yet obtained. Here, tben. we stand in face 

 of another highly important question; for the limit at which 

 the warm water of the Atlantic meets the cold indraught 

 from the Polar Sea. must. reasoning from analogy, mark 

 the limit of distribution for the animals inhabiting the 

 warm and cold areas. But. trifling as is our knowledge 

 of depth and temperature in that ocean-region, we know 

 still less concerning the nature of its currents. -- a phy- 

 sical condition which everywhere exerts such great influence 

 on the character of the marine fauna. -- concerning the 

 chemical constituents of its water, no less important in 



