Table of Contents. 



Page 



Introduction. Historical Summary 3 



The Periodicity of the Sun-spots 3 



Tlio Motions of the Sun-spots 9 



The Distribution of the Sun-spots 13 



Chapter I. The Material of Observation and its first Treatment 16 



Chapter II. The Longitude Motions of the Sun-spots 21 



A. The Classification of the Observations 21 



B. Characteristics of the Motions in Longitude 23 



Summary of the Method employed .. 23 



Mean and Dispersion 27 



Skewness and Excess 28 



C. The Rotation Period of the Sun, computed from the Longitude MotiOHS of 



the Spots 32 



D. The Motions in Longitude of Spots of different Sizes 42 



Chapter III. The Latitude Motions of the Sun-spots 16 



A. Characteristics of the Motions in Latitude 46 



B. On the Position of the Sun's Axis 52 



Chapter IV. The Dispersion of the Motions for different Spot-sizes 61 



Chapter V. Correlation between the Longitude and Latitude Motions of the Sun-spots 65 



Chapter VI. The Distribution of Sun-spots on the Sun's Surface 77 



A. The Distribution of Spots in the two Hemispheres 77 



B. The Distribution of Spots on both Halves of the Sun 79 



C. The Place of Origin of the Sun-spots. Discussion of the Opinion of Stephani 81 



Chapter VII. The Effect of a Refraction in the Solar Atmosphere 89 



A. The Longitude Motions of the Spots at different Distances from the Central 



Meridian 89 



B. On the Possibility of two Drifts in the Motions of the Sun-spots 91 



Summary 93 



Lunds Universitets Årsskrift. N. F. Afd. 2. Bd 10. 13 



