CONTENTS. 



INTRODUCTION. Page 



Art. i. The first Expedition, 1897 - ' i 



2. The second Aurora Expedition, 1899 1900 5 



THE EXPEDITION OF 1902 1903 9 



4, 5. The Auroral Station in Kaafjord 10 



6, 7. The Auroral Station in Dyrafjord, Iceland 18 



8, 9. The Auroral Station in Spitsbergen - 24 



10, n. The Auroral Station in Novaja Semlja 31 



12. The Working-up of the Material 37 



PART I. 



MAGNETIC STORMS, 19021903. 

 INVESTIGATIONS BY MEANS OF DIURNAL REGISTERINGS FROM 25 OBSERVATORIES. 



CHAPTER I. 

 PRELIMINARY REMARKS CONCERNING OUR MAGNETIC RESEARCHES. 



13. Our Aim and our Method of Working 41 



14. On the Calculation of the Perturbing Force 44 



15. On the Separation of Simultaneous Perturbations 47 



CALCULATION OF THE SCALE-VALUES FOR THE REGISTERINGS AT THE NORWEGIAN STATIONS. 



1 6. Determination of the Scale-Values for the Declinometer 48 



17. Determination of the Sensibility of the Variometers for the Horizontal and Vertical Intensity 48 



18. Determinations of Sensibility for Kaafjord and Bossekop 5 



19. Determinations of Sensibility for Dyrafjord 51 



20. Determinations of Sensibility for Axeleen 53 



21. Determinations of Sensibility for Matotchkin Schar 54 



22. Temperature Coefficients for the Registerings 55 



23. Explanation of the Charts 56 



24. The Copies of the Magnetic Registerings, Explanation and General Remarks . . . 58 



CHAPTER II. 

 ELEMENTARY PERTURBATIONS. 



25. General Remarks 61 



2.6. The Equatorial Perturbations 62 



27. The Positive Equatorial Perturbation. The Perturbation of the 26th January 1903 . . 63 



28, 29. The Perturbations of the 9th December, 1902 7 



30. The Perturbation of the 23rd October, 1902 7^ 



