afgrændser sig mod det indenfor flydcnde meget ferskere 
Vand. Forøvrigt holder Grændsen for det saltere Over- 
riadevand sig meget langt tilhavs med Undtagelse al, at 
den ved den 70de Breddegrad paa en ganske kort Stræk- 
ning kaster sig tæt ind under Kysten. 
Denne Fortynding af OverHadevandet, som overalt 
ytrer sig - ved den norske Kyst. er intetsteds ledsaget af 
nogen væsentlig Forrykkelse af Overfladetemperatureu. Salt- 
gehaltens Formindskelse skyldes her aabenbart detfraKys- 
terne udstrommende Flodvand, der om Sommeren besidder 
en ikke ringe Varmegrad, saaledes at man i den mest 
fremtredende Kyststrøm langs Norges Vestkyst endog lin- 
der en noget høiere Overlladetemperatur end paa nærlig- 
gende Puncter. Ganske anderledes stiller Sagen sig paa 
den mod den østgrønlanskc Polarstrøm vendende Side, 
hvor OverHadevandet fortyndes ikke ved Flodvand men 
ved det ved Havisens Smeltning dannede, stærkt afkjølede 
Ferskvand, og det viser sig derfor, at en Synken i Saltge- 
halten her bestandig er ledsaget af en tilsvarende Formind- 
skelse af Overfladetemperaturen. Grændsen for det saltere 
Vand i Overfladen følger derfor paa denne Side ofte Po- 
larstrømméns Grændse, # og selv der. hvor den forlader 
denne, optræder der dog samtidig med Overgangen fra 
saltere til ferskere Vand altid meget tydelige Variationer 
i Temperaturen, der gaa i samme Retning som Saltgehal- 
tens. At Overfladetemperaturen synker, naar man enten 
nærmer sig eller overskrider Grændsen for 3.50 °/„ Salt, 
vise Observationerne No. 115 til 120 og No. 207 til 209. 
I selve Polarstrømmen er Saltgehalten i Overfladen i 
nogen Afstand fra Grændsen oftest fundet meget lav, kun 
paa et Sted optræder i saa Henseende en Undtagelse fra 
den almindelige Regel, idet der omtrent paa den 75de 
Breddegrad skvder sig en smal Tunge med Vand af høiere 
Saltstyrke ind over Polarstømmen, uden at der dog derved 
bevirkes nogen væsentlig Forhøielse af Overfladetempera- 
turen. En Mærkelighedj som fortjener at omtales, er den, 
at Professor Dr. G. O. Sars, som paa Expeditionens Tog- 
ter jevnlig undersøgte Dyrelivet i Overfladen, netop paa 
dette Punct langt inde i Polarstrømmen har gjenfundet de 
for det varmere Atlanterhavsvand eiendommelige Dy refor- 
mer. der forresten intetsteds ellers ere fundne i den øst- 
gi’onlandske Koldvandsstrøm. 
Med Hensyn paa Saltmængderne i de større Dyb 
henvises til Kartet No. 11. hvori paa samme Maade som 
ovenfor Andes indtegnet Saltgehalten ved Havbunden samt 
i de intermediate Dyb, forsaavidt Observationerne refererer 
sig til Puncter saa dybt under Overfladen, at Temperatu- 
ren der ligger under 0°. Hvor en Observation hidrører 
fra et intermediært Dyb, er Tallet i Kartet understrøget. 
Naar man bortser fra enkelte i Nærheden af Kys- 
tenie og paa grundt Vand optagne Vandprøver, varierer 
Saltgehalten paa de store Dyb mellem 3.59 og 3.45 %, 
of the salt ocean-water of the Atlantic, distant but a lew 
miles from land, its boundary being distinctly marked by 
the limits of the brackish water flowing along the shore. 
Except in this region, and a locality bordering the 70th 
parallel of latitude, where, tor a short distance, it runs 
close to the coast, the boundary of the salt surface-water 
lies far out at sea. 
This dilution of the surface-water on all parts of the 
Norwegian coast is not anywhere found to exert a material 
influence on the surface-temperature. The decrease in the 
amount of salt must be obviously ascribed to the influx ol 
river-water, the temperature of which during the summer 
months is relatively high, — so high indeed, that the 
principal coastal current, flowing along the western shores 
ol' Norway, has a, somewhat higher surface-temperature than 
that observed in its immediate vicinity. • Phenomena the 
reverse of these prevail in the tract of ocean exposed , to 
the influence of the Arctic, or East Greenland, current. 
There, the surface-water is not diluted by an influx of river- 
water, but with freshwater of a low temperature, produced 
by the melting of drift-ice; and hence a decrease in the 
percentage of salt is invariably attended with a correspond- 
ing reduction of the surface-temperature. The salt surface- 
water borders, therefore, not infrequently the Arctic current; 
and even where its boundary diverges from it. the transi- 
tion from salt to comparatively fresh water is always ac- 
companied by a • very considerable variation in temperature, 
proportionate to the variation in the amount of salt. That 
the surface -temperature becomes gradually lower on- ap- 
proaching the limits of the section in which the proportion 
of salt is 3.50 per cent, will be seen from the series of 
observations Nos. 115 — 120 and Nos. 207 — 209. 
In the Arctic current, some distance from its extreme 
boundary, the proportion of salt at the surface was found 
to he very small, except in one locality, near the 75th 
parallel of latitude, where a narrow strip of salter water 
flows into the current, without, however, causing an appreci- 
able rise in the surface-temperature. It is a remarkable 
fact, which must not be passed by unnoticed, that Profes- 
sor G. 0. Sars, naturalist to the Expedition, found here 
in the surface-water, which lie examined from day to day, 
forms of animal life peculiar to the warm area of the 
Atlantic water, which be never met with in any other part 
of the cold East Greenland current. 
As regards the amount of salt observed at great 
depths, the reader is referred to Pl. II, in which, as in 
Pl. 1. will be found the percentage both at the bottom 
and at intermediate depths, provided the observations were 
taken with samples of water the temperature of which in 
situ was below 0". Observations with water from interme- 
diate depths are denoted by underlining the figures ex- 
pressing their results. 
Disregarding a few samples of water collected .near 
the coast and in shallow spots, the proportion of salt, 
where the depth is great, ranges from 3.59 to 3.45 per 
