48 
Ekman 1 og Thorpe og Riicker 8 . har givet meget fuldstæn- 
dige Tabeller over Søvandets Volumina ved forskjellige 
Temperaturer, hvorhos tillige ogsaa Dr. Karsten» bar op- 
stillet en Correctionstabel. hvoretter man kan reducere de 
ved vilkaarlige Temperaturer aflæste Bgenvægter til 17 .° 5 . 
Sammenstiller man de Correctioner. som efter disse Iagt- 
tagelser kunne beregnes, erholder man imidlertid især for 
de lavere Temperaturer meget daarligt overensstemmende 
Yærdier. idet der kan optræde Difterenter, der endog kan 
overskride 0 . 0004 , mellem <le af Ekmann's og Hubbard’s 
Observationer beregnede Correctioner. hersker der den 
største Overensstemmelse, men ogsaa her gaar Different- 
serne paa enkelte Puncter op til meget nær 0 . 0001 . I 
Betragtning af disse tildels temmelig betydelige Uoverens- 
stemmelser mellem de liidtil publicerede Undersøgelser af 
denne Art kunde det ikke findes ubeføiet endnu engang 
at gjenoptage Bestemmelserne af Søvandets Volumina ved 
forskjellige Temperaturer, og jeg besluttede mig derfor til 
gjenuem egne Undersøgelser at forvisse mig om. hvilken af 
de opstillede Tabeller der bedst svarede til Udvidelsen af 
det i det norske Nordhav flydende Vand. Dels i dette 
Øjeined dels for at bestemme de benyttede Aræometres 
Correctioner og de Constanter, hvormed Chlorprocenterne 
og Decimalerne i Egenvægten maatte multipliceres for at 
give Saltmængden. har jeg anstillet Undersøgelser med føl- 
gende Vaudprøver, 
Bredde. 
Længde 
Dybde 
Station. 
fra Greenwich. 
Eng. Fra. 
Meter. 
245 
68° 2 1 ' 
2° 5 ' v. 
O 
O 
247 
O' 
00 
Cn 
Cn 
2 24 0. 
500 
941 
253 
Skjærstadfjord. 
0 
0 
254 
67" 27' 
13" 25' 
0 
0 
284 
73 1 
12 58 
0 
0 
300 
73 10 
3 22 V. 
0 
0 
349 
76 30 
2 57 0 - 
1487 
27 x 9 
362 
79 59 
5 40 
0 
0 
hvilke jeg for Kortheds Skyld i den Orden, hvori de her 
findes opforte. vil betegne med I. II o. s. v. indtil A III. 
Til Bestemmelse af Søvandets Udvidelse benyttede jeg et 
Sprengels Pyknometer 4 , forarbeidet af to Stykker meget 
tynde Glasrør af et og samme Rør med en indvendig Dia- 
meter af omtyent 13 mra . 'Rørene vare nedentil sammenlod- 
dede ved Hjælp af et snævert kort u-formig bøiet Glasrør 
og oventil paaloddede knæformig bøiede solide Oapillarrør 
med meget fin Aabning. Ved Paalodn ingen at disse Glas- 
rør blev der saa meget som muligt draget Omsorg lor. at 
kun en liden Del af de videre Rør udsattes for Opvarm- 
ning over Blæselampen, fornt ikke Apparatet derved [skulde 
1 Kongl. Svenska Vétenskapsak. Handlingar 1870 — 1. 
2 Proc. Roy. Soc., ‘24 — 159. 
a Tafeln zur Berechnung der Beobachtungen aii den Kiistensta- 
lionen u. -s. w. Kivi 1874. 
4 Pogg. Ann. 150 — 459. 
Ekman 1 , and Thorpe and Rucker 2 * having prepared com- 
prehensive Tables to show the volume of sea-water at diffe- 
rent temperatures; Dr. Karsten 8 , too. has published a Table 
of Corrections by which specific gravities read at any tem- 
perature may be reduced to 17 .° 5 . Meanwhile, on comparing 
together the corrections computed from these observations, 
the values obtained, more especially lor low temperatures, 
are found to agree but very indifferently, the difference in 
some cases exceeding even 0 . 0004 . The agreement is 
closest between the corrections computed from Ekman s 
and Hubbard's observations; but here, too. the difference for 
some temperatures amounts to very nearly 0.000 1. ( ou- 
sidering. therefore, the want of uniformity, in some cases 
very considerable, exhibited by such observations of this 
kind as had till then been made public, it could not be 
deemed superfluous to investigate anew by a further series 
of experiments the variation in volume which sea-water 
is found to undergo at different temperatures; and hente I 
determined on ascertaining from the results of my own ob- 
servations which of the aforesaid Tables corresponded best 
with the expansion of the water in the Norwegian Sea. 
Partly with this object in view, and partly in order to 
determine the corrections for the areometers and the con- 
stants by which the percentages of chlorine and the deci- 
mals of specific gravity had to be multiplied when com- 
puting the amount of salt. I examined the following sam- 
ples of water: — 
Latitude. 
• 
Longitude 
Depth 
Station. 
from 
Greenw. 
Eng.Fath. 
Metres. 
245 
68" 2? 
2 0 
5 'W. 
O 
0 
247 
68 5.5 
2 
24 E. 
500 
941 
253 
The Skjærstad Fjord. 
0 
0 
254 
67° 27' 
J 3 ° 
25' 
0 
0 
284 
73 1 
12 
58 
0 
0 
300 
73 Jo 
3 
22 W. 
0 
. 0 
349 
76 30 
2 
57 E. 
1487 
2719 
362 
79 59 
5 
40 
0 
0 
which I will indicate, for the sake of brevity, by the Roman 
numbers from I to VIII. and in the order in which they 
are given here. For determining the expansion of the sea- 
water. I made use of Sprengels pycnometer; 4 the instru- 
ment was constructed of two pieces of glass tubing, cut oft 
from the same length, with an inner diameter of about 13 ”"". 
These tubes were sealed together at their lower ends 
by means of a short, narrow glass tube, bent into the form 
of the letter U. and had strong knee-shaped capillary tubes 
sealed on to their upper extremities. AVhen sealing on 
these glass tubes, the greatest care was taken to confine 
the heat from the glass-blower’s lamp to as small a portion 
1 Kongl. Svenska Vetenekapsak. Handlingar 1870, 1. 
2 Proc. Roy. Soc., 24; p. 159. 
Tafeln zur Berechnung der Beobadijungen an den Kiistensta- 
tionen u. s. w. Kiel 1874. 
4 Pogg. Ann. 150, p. 459. 
