181 



IV. MAGNETIC OBSERVATIONS OF THE "SCOTIA," 1902-1904. 



CONTENTS. 



Pages 



Introductory remarks, by Dr. 0. CHBBE, F.B.S 181 



Notes, by Mr. B. C. MOSSMAN, F.R.S.E 181 



Discussion of the observations, by Dr. CH BEE 184 



1. Nature of observations 184 



2. Declination. Absolute observations 184 



3. Inclination. Absolute observations 184 



4. Horizontal force. Absolute observations 184 



5 and 6. Diurnal variation of declination 185 



7. Fourier series 186 



8. Comparison with Pawlowsk 186 



9. Absolute declination for epocli January 1, 1904 186 



INTRODUCTORY EEMARKS. 



AN account of the site where the magnetic observations were taken, and various historical details, will be 

 found in the following notes by the observer, Mr. R. C. MOSSMAN, F.R.S. E. 



Accompanying the note is a Map of Laurie Island, showing the position of the magnetic hut 

 (Copeland Observatory), also two Plates, of which Plate 20 shows the position of the hut in relation to the 

 central cairn and house; Plate 21, fig. 1, shows the taking of preliminary observations on the site of the 

 future hut, and, fig. 2, plan showing the positions of the magnetic instruments inside the hut when in use. 



The instruments were compared with the standard instruments at Kew before the expedition set sail, 

 and gave satisfactory results. 



C. C. 



NOTES ON THE MAGNETIC WORK OF THE EXPEDITION. 



BY 



R. C. MOSSMAN, F.R.S.E. 



The Scottish National Antarctic Expedition was equipped with the primary object of engaging in 

 Hydrographical, Biological and Meteorological investigation in the Antarctic area known as the Weddell 

 Sea. The expedition was not fitted out to prosecute magnetic work, but oceanographical research on the 

 lines of the " Challenger," " Valdivia " and other deep-sea expeditions, which work was to be carried on in 

 high southern latitudes within the limits of floating ice. The ship was in no way suited for the taking of 

 magnetic observations at sea, there being no specially constructed non-magnetic area, as in the case of the 

 " Gauss " and the " Discovery." Besides this, the heavy trawling and other gear made it almost impossible 

 that this should be the case. Further, it was foreseen at the outset that even if it had been possible to 

 have a non-maguetic area, to carry on deep-sea work and magnetism was incompatible. Our magnetic 



