58 



rimeligst bliver at tilskrive Observatiansfeil. Som Chlor- 

 coefficient kan heraf opstilles 



1.809 + 0.00076 



med en sandsynlig Feil af en enkelt Bestemmelse af+ 0.002 

 og som Egenvægtscoefficient 



131.9 + 0.058 



med en sandsynlig Feil af en enkelt Bestemmelse af+ 0.15. 



Disse Værdier stemme især for Chlorcoefficientens 

 Vedkommende ganske vel overens med tidligere fundne 

 Værdier, saaledes har baade Forchhammer og Ekman i 

 Middel fundet 1.811. medens de af Andre opstillede Egen- 

 vægtscoefficienter overalt ere noget mindre end den af mig 

 fundne. 



Ved Hjælp af disse ( !oeffi,cienter har jeg af de paa 

 Expeditionens Togter udforte Chlor- og Egenvægtsbestem- 

 melser beregnet Vandprøvernes Saltgehalt og sammen med 

 Originalobservationerne opført dem i nedenstaaende Tabel. 



Egenvægteme ere i Regelen kun aflæste med 4 Deci- 

 maler. det 5te er kun opført, hvor det havde en Vferdi nær 

 ."i. saa at det kunde være Tvivl underkastet, om der ved 

 Airunding skulde formindskes eller foi-bøies. I de reduce- 

 rede Egenvægter tindes ligeledes kun opført 4 Decimaler, 

 hvor det uden Tvivl kunde afgjøres, til hvilken Side 

 Afrundingeu skulde tinde Sted, bvorimod der i modsat 

 Fald ogsaa der er tilføiet et 5te. De med :|: betegnede 

 Egenvægter ere aflæste paa Axæometre, hvis Correction 

 ikke er bleven bestemt. Til Optagelse af de til Qnder- 

 søgelse af Saltholdighedeh bestemte Vandprøver er foruden 

 det tidligere beskrevne, af Wille construerede, Apparat og- 

 saa paa grundere Vand ofte benyttet den af Ekman an- 

 givne fortrinlige Vandhenter. som imidlertid ifølge den Frem- 

 gangsmaade, hvoretter Dyblodninger paa. den norske Ex- 

 pedition foretoges, ikke egnede sig til Brug ved større Dyb. 



Ved Velvillie af Professor Mohn bar jeg faaet op- 

 givet de undersøgte Vandprøvers Temperatur i Havet, hvor- 

 ved det er bleven muligt ogsaa at tilfoie en Rubrik for 

 tieres Egenva'gter ved denne Temperatur i Forhold til 

 rent Vand af 4°. 1 Af.de i Tabellen gjengivne Observa- 

 tioner ere alle indtil No. 149 udforte paa Iste Togt af 

 Svendsen, alle fra 14'.l til 225 paa 2det Togt- af mig. de 

 ovrige ere udforte paa sidste Togt af Scluuelck og mig i 

 Fællesskab, saaledes at det største Anta] skyldes Schinelck, 

 der dette Aar medfulgte Expeditionen. 



1 f t < ■ 1 1 1 Vand af r er ved denne Reduction valgt som Enhed, 

 fordi 'len allerede tidligere er anvendt af J. Y. Buchanan (Proo. 

 I!ev. See. •_• i —597). Ved Beregning al' Egenvsegternes Værdi 

 ■ ■'I Havets Temperatur i Forhold til Vand al' r er Forhol- 

 det mellen, Volumet al' reni Vand ved I" og I7.°:>sat =0.998768. 



and hence the variation in the results should most prob- 

 ably be aseribed to errors of observation. The coefticient 

 of chlorine. may accordingly be tåken at — 



1.809 + 0.00076 



with a probable error in a single determination of + 0.002, 



and the coefticient of specitic gravity. at — 



131.9 + 0.058 



with a probable error in a single determination of +0.15. 



These valnes agree closely, in particular as regards 

 the coefticient of chlorine. with those previously f mnd. 

 Thus. for instance. the mean value found both by Forch- 

 hammer and Ekman was 1.811. whereas the coefficient of 

 specitic gravity given by former observers is somewhat 

 lower tban mine. 



By means of these coefticients I have computed from 

 the determinations of chlorine and specitic gravity the 

 amount of salt in the samples of water collected on the 

 Expedition. and have set down the observations and their 

 results in the accompanying Ta ble. which calls for a brief 

 explanation. 



The specitic gravities are as a rule not read to more 

 than 4 decimals. a tiftli being added only in the event of 

 its baving a value ut' 5, in which case it is otten doubtful 

 whether, when rounding off the tigures. there should be 

 increase or diminishment. Thereduced specitic gravities. too. 

 are expresed with 4 decimals only. wherever it was mani- 

 fest in- which direction the rounding off bad to be made: 

 when sucb is not the case. a fifth has been added. An 

 asterisk at the side of :i specitic gravity denotes that the 

 latter was determined with an areometer for which no 

 correction bad been found. Besides the instrument devised 

 by Wille. of which a description bas been given, Ekman's 

 excellent apparatus was likewise made use of. in compara- 

 tively shallow localities. for colleeting the samples of sea- 

 water in which to determine the amount of salt: the mode 

 of sounding practised on the Norwegian North-Atlantic 

 Expedition would not admit of its adoption lnr greater depths. 



Professor Mobn bas kindly furnished me with the 

 temperatures of the samples of water in s/tu. which lias 

 enabled me to give an aditional column for the specitic 

 gravities at those temperatures as compared with pure 

 water of 4". ' Df the observations given in the Table. 

 those extending from No. 1 to No. 149 were performed 

 on the first voyage, by Mr. Svendsen; those extending from 

 No. 14',i to No. 225, on the second voyage. by myself; the 

 remainder were tåken on the last voyage. by Mr. Schmelck 

 and myself conjointly. the greater number. however. by Mr. 

 Schmelck. who that year accompanied the Expedition. 



1 Pure «aler of 4" was choseD as the unit bf reduction, .1. Y. Bu- 



clianaii having previouslj adopted il as suc-h (Pt ol' Roy. 



Sne. 24, \>. r >97). When computing the specific gravities at the 

 temperature el' the sea, as compared with water et' I", the 

 ratio existing between the vol I' pure water at r and I7."."> 



was assiiiueil hi he 0.998768. 



