18 



disse Omstændigheder var det desvaTre. at jeg ikke kunde 

 faa nogen brugbar Bestemmelse af Indexfejlen. Denne 

 har jeg senere sogt at finde saaledes : 



be dispensed with. As a consequence of* tliese atmosplieric 

 conditions. I failed to obtain a trustwbrthy determination 

 of the index-error. This I souglit subsequently to tind in 

 the following manner: — 



I Hammerfest den 9de Juli 1878 ved en Temperatur af + 8° 0. var Indexfejlen (Index-error) -\- 2' 1" 

 , 10de „ .. .. .. + 10 „■„. — • + 23 



.. Christiania ,, Ilte Decb. — „ „ ,, — 3 .. — -f 2 27 



Under Observationerne i Advent Baj var Luftens 

 Temperatur -f- 3°, hvortil, efter grafisk Interpolation. svarer 

 en Indexfejl af -j- 2' 16", der er benyttet til Beregningen 

 af Hojderne. 



Den benyttede Solradius er den, som er utlledet af 

 Sammenligning mellem Observationerne af ovre og nedre 

 Solrand. ■ 



Observatiousuhr var mit Lommechronometer. der før 

 og efter sammenliknedes med Hovedchronometret Reid 

 ombord. 



Reid 19* 4 m 0.*0 0" 55 m 0.'0 



Lommechron. 19 53 58.6 1 44 57.2 

 ' Corr. t. Reid — 49 58.6 — 49 57.2 

 Efter de timevise meteorologiske Iagttagelser ombord var 



ved Morgenobs. Kl. 9 a. ni. Baroni. = 755. """1 Temp. = 3.°0 

 „ Efterm.obs. .. ' 1 p. m. — 755. — 2. 6 



During the observations tåken at Advent Bay. the 

 temperature of the atmosphere was -|- 3". to which, as 

 found from diagrammatic interpolation, corresponds an 

 index-error of + 2' 16". that assumed for computing the 

 altitudes. 



The apparent semidiameter of the sun tåken for the 

 computation, is that determined from a comparison of the 

 observations of the lipper and lower limbs. 



On this occasion, I observed with mv pocket-chrono- 

 meter, which, before and after the observations, was com- 

 pared on board with- the chief timekeeper (Reid). 

 Reid 19* 4"' 0.'0 0* 55'" 0/0 



Pocket-chrou. 19 53 58.6 1 44 57.2 

 Corr. to Reid - 49 58.6 — 49 57.2 

 According to the hourly meteorological observations 

 on board. the temperature and barometric pressure were 

 as follows: — 



9 a. m. Barometer 755."""! Temp. 5.°0 

 1 d. m. 755. 2. 6. 



1878. August (August) 19 — 20. 



Lommechron 



(Pocket-Chronometcr) 



h' 



20' 



J. 



Lommechron. 



■ ' 'kronomi ter) 



Ved de mindste Kvadraters Methode har Hr. Åstrand 

 fundet, idet der sættes «/ = 78°' 14' 48". l„ = 1'' 2"' 

 15/9, og Reids Correction til Greenwich Middeltid ved 

 Pormiddagsohservationerne + 16"* 0/0, 



By the method of the least squares, putting </„ = 

 78° 14' 48". /.,, = l* 2" 15/9, and the Reid correction 

 to Greenwich inean time for the a. m. observations = - 

 KV» 0/0, Mr. Å.strand found 



å = + 3."3 



/ q> = -f 0."4 + l."l. / /. = '+ ( -»."3 ± 7. '-'8 = + D/02 ± 0/52. 



