I de øverste Vandlag hender det undertiden, at Tem- 
peraturen snart er aftagende, snart voxende med Dybden. 
I saadanne Tilfælder er det vanskeligt, ja tildels umuligt, 
at finde de rigtige Temperaturer med Indexthermometret. 
I Danmarkstrædet er Lieutenant Caroc kommet til gode 
Resultater ved Anvendelse af saavel Maximums- som Mini- 
mums-Indexen og en kritisk Anordning og Discussion af 
Tagttagelserne. ! 
En noget anden Fremgangsmaade har flere Gange 
oivet mig ganske vel brugbare Resultater i saadanne Til- 
fælder, i hvilke Temperaturen først synker med Dybden og 
derpaa voxer. Den bestaar i at fire Thermometret ud saa 
varmt, at det naar de dybere Lag med et Temperaturover- 
skud over det omgivende Vand. Efter at have ladet Instru- 
mentet accommodere sig, hvorved Minimumsindexen vil re- 
gistrere den stedfindende Temperatur, haler man det op 
saa hurtigt som muligt. Instrumentets Træghed beskytter 
det mod en merkelig yderligere Afkjoling, medens det pas- 
serer mellemliggende koldere Lag. Aftager Temperaturen 
atter i en større Dybde, faar man de dybere Lags Tem- 
peratur meget godt registreret med Minimumsindexen. Saa- 
danne Tilfælder forekomme jevnlig om Sommeren i den 
grønlandske Polarstrøm, paa de ydre Strøg, hvor den ikke 
fører Drivis. Temperaturen aftager fra Overfladen til en 
vis Dybde, f. Ex. 50 Fayne, hvor den naar et Minimum, 
stiger derpaa til et secundært Maximum, f. Ex. i omtrent 
100 Favnes Dybde, og aftager tilsidst stadig indtil Bunden. 
Det første Temperaturminimum faar man naturligvis nøj- 
agtigt bestemt ved Minimumsindexen; det andet Maximum 
kan muligens blive noget afstumpet under Thermometrets 
Dvælen i de ovenforliggende koldere Lag, naar man, som 
sædvanligt, tager Temperaturrækken i en Sats med flere Ther- 
mometre paa forskjellige Steder af Lodlinen, der kræve 
lidt Tid for at løses fra denne; de dybere Lags Tempera- 
tur faar man derimod desto sikkrere bestemt, jo lavere Tem- 
peraturen selv er. Blive saaledes de mellemliggende rela- 
tiv varmere Lags Temperatur muligens noget for lavt regi- 
strerede, saa faar man dog ved Temperaturrækken udtrykt 
den rigtige Karakter af Temperaturens Fordeling. Man 
sammenligne Temperaturrækkerne No. 297 og 298. (Pl. VI). 
Den første er taget udelukkende med Indexthermometre og 
giver følgende Maxima og Minima: Overfladen + 49.4, 60 
Fayne: — 09.8, 150 Favne: omtrent — 0°.2, 1280 Favne ved 
Bunden: — 1°.4. Den anden Række er taget udelukkende 
med Vendethermometret Negretti & Zambra No. 91, og giver: 
Overfladen: + 4°.0, 50 Favne: — 10.2, 120 Favne: +- 00.04, 
1500 Favne ved Bunden: — 12.5. 
I Fjordene paa Norges Vestkyst finder man under- 
tiden om Sommeren, at Temperaturen først aftager fra 
" Geografisk Tidskrift, udgivet af Bestyrelsen for det kongelige 
danske geografiske Selskab, 1878, S. 98. ' 
Den norske Nordhavsexpedition. H. Mohn: 
In the uppermost strata it will sometimes happen 
that the temperature is now found to diminish, now to 
increase with the depth. In such cases it is difficult, nay 
well-nigh impossible, to find the right temperature with the 
index-thermometer. In Denmark Strait, Lieutenant Caroc 
attained excellent results by using both the maximum and 
minimum index, together with a critical arrangement and 
discussion of the observations. ! 
A somewhat different method has on 
sions procured me very fair results, viz, when the tempe- 
rature first diminishes with the depth and then increases. 
It consists of lowering the thermometer sufficiently warm 
to admit of its reaching the lower strata with a tempera- 
ture exceeding that of the surrounding water. After giving 
the instrument time to accomodate, when the minimum- 
index will register the existing temperature, the line is 
hauled in as quickly as possible. The sluggishness of the 
several occa- 
instrument guards against any further sensible cooling 
whilst passing through the intermediate colder strata. 
Should the temperature again decrease at a greater 
depth, you get the temperature of the deeper strata well 
registered by the minimum-index. Such cases are of fre- 
quent occurrence throughout the summer in the Greenland 
Polar current, viz., its outer tracts, where there is no drift- 
ice. The temperature diminishes from the surface to a 
certain depth, e. g. 50 fathoms, where it reaches a mini- 
mum, then increases to a secondary maximum, e. g. at a 
depth of about 100 fathoms, after which it steadily dimi- 
nishes down to the bottom. The first minimum of tempe- 
rature will of course be accurately determined by the mi- 
nimum-index; the second maximum may possibly be some- 
what reduced during the stoppage of the thermometer in 
the superincumbent colder strata, when, as is generally the 
case, serial temperatures are taken one operation 
with several thermometers attached to different parts of 
the line, because a little time is required to detach 
the instruments; the temperature of the deeper strata 
on the other hand is determined with the greater accuracy 
Now, should, perhaps, the 
relatively warmer 
in 
the lower the temperature. 
temperature of the intermediate and 
strata be registered a little too low, the whole series will 
nevertheless express the true character of the distribution 
of temperature. Compare the serial temperatures Nos. 297 
and 298. (Pl. VI). The first was taken exclusively with the 
index-thermometers and gives the following Maxima and Mi- 
nima: Surface + 4°.4; 60 fathoms — 09.8; 150 fathoms about 
—o?.2; 1280 fathoms (at the bottom) — 1°.4. The other 
series was taken exclusively with the inverting-thermometer, 
Negretti & Zambra No. 91, and gives: Surface + 40.0; 
50 fathoms — 1°.2; 120 fathoms + 09.04; 1500 fathoms 
(at the bottom) — 12.5. 
In the fjords on the West Coast of Norway the tem- 
perature is sometimes found in summer first to diminish 
' Geografisk Tidskrift, udgivet af Bestyrelsen for det kongelige 
danske geografiske Selskab, 1878, p. 98. 
Nordhavets Dybder, Temperatur og Strømninger. 6 
