48 



Ekman 1 og Thorpe og Riicker 2 hur givet meget fuldstæn- 

 dige Tabeller over Søvandets Volumina ved forskjellige 

 Temperaturer, hvorhos tillige ogsaa Dr. Karsten 3 har op- 

 stillet en Oorréctionstabel, hvoretter man kan reducere de 

 ved vilkaarlige Temperaturer arlæste Egenvægter 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 

 Værdier, idet der kan optræde Differenter, der endog kan 

 overskride 0.0004, niellem de af Ekmann's og Hubbard's 

 Observationer beregnede Correctioner. hersker der den 

 storste Overensstemmelse, men ogsaa her gaar Different- 

 serne pa a enkelte Puncter op til meget nær 0.0001. I 

 Betragtning af disse tildels temmelig betydelige Uoverens- 

 stemmelser mellem de hidtil publicerede 1'ndersoge.lser af 

 denne Art- kunde det ikke tindes uhefoiet endnu engang 

 at gjenoptage Bestemmelserne af Søvandets Volumina ved 

 forskjellige Temperaturer, og jeg besluttede mig derfor til 

 gjennem egne Undersøgelser at forvisse. mig om. hvilken af 

 dé opstillede Tabeller der bedst svarede til Udvidelsen af 

 det i det norske Nordhav Hydende Vand. Dels i dette 

 Øjemed dels for at bestemme de benyttede Aræometres 

 Correctioner og de Constanter. hvormed Clilorprocenterne 

 og Decimalerne i Egenvægtén maatte multipliceres for at 

 give Saltmængden. har jeg anstillet Fndersøgelser med føl- 

 gende Vandprover. 



hvilke jeg for Kortheds Skyld i den Orden, hvori de her 

 tindes opforte. vil betegne med I, II 0. s. v. indtil VIII. 

 Til Bestemmelse af So våndets Udvidelse benyttede jeg et 

 SprengeFs Pyknometer*, forarbeidet af to Stykker meget 

 tynde Grlasrør af et og samme Ror med en indvendig Dia- 

 meter af omtrent 13""". Horene vare nedentil sammenlod- 

 dede ved Hjælp ai' et snæyert kort u-formig bøiet Gkisrør 

 og oventil paaloddede knæformig bøiede solide Capillarror 

 med meget tin Aabning. Ved Paalodningen af disse Glas- 

 ror blev der saa meget som muligt draget Omsorg for. at 

 kun en liden Del af de videre Rør udsattes for Opvarm- 

 ning over Bkeselampen. foråt ikke Apparatet derved skulde 



1 Eongl. Svenska Vetenskapsak. Handlingar 1*70 — 1. 

 - Proc. Roy. Soc, J t 159. 



' Tafelii /nr Berechnung der Beobaohtungen an den Custensta- 

 tionen 11. s. w. Kiel 1*74. 

 ' Pogg. Ann. 150 459. 



Ekman 1 , and Thorpe and Pucker 2 liaving prepared com- 

 prehensi ve Tables to show the volume of sea-water at diffe- 

 rent temperatures; Dr. Karsten 1 , too. has published a Table 

 of Corrections by which speeific gravities read at any tem- 

 perature may be reduced to 17. °5. Meanwhile, on eomparing 

 together the corrections computed from these observations. 

 the values obtained. more especially for low temperatures. 

 are found to agree hut 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 0.0001. Con- 

 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 auew by a further series 

 of experiments the variation in volume which sea-water 

 is found to undérgo at different temperatures; and hence I 

 determined <>n 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 perceutages of chlorine and the deci- 

 mals of speeific gravity bad to be multiplied when com- 

 puting the amount of salt. I examined the following sam- 

 ples of water: — 



which I will indicate, for the sake of brevity. by the Roman 

 numbers from I to VIII, and in the order iu which they 

 are given here. For determining the expansion of the sea- 

 water. I made use of SprengeFs pyenometer; 4 the instru- 

 ment was constructed of two pieces of glass tubing. cut off 

 from the same length. with an inner éBameter of aboutlo""". 

 These tubes were sealed together at their lower euds 

 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. When sealing on 

 these glass tubes, the greatest care was tåken to confine 

 the heat from Ihe glass-blower's lamp to as small a' portion 



1 Kongl. Svenska Vetenskapsak. Eandlingar 1870, 1. 

 - Proo. Roy. Soc, 24, p. 159. 



* Tafeln zur Berechnung der Beobaohtungen an den Cvistensta- 

 tionen n. s. w. Kiel 187 1. 



