List of contents. 



CHAPTER I. 



Historical Introduction 5 



Catalogue of observations of the velocities of the stars in the line of sight 9 



CHAPTER II. 



The different systems of coordinates to wich the velocities are referred 12 



Determination of the direction and the magnitude of the relative motion of the sun from radial 



velocity observations 13 



i he constant K % 21 



The mean errors in the solar velocity determinations 26 



CHAPTER in. 



The mean velocities of stars from observations in the line of sight 27 



The ellipsoidal hypothesis in its generalized form 30 



Examination of the velocity distribution of stars of different spectral classes in relation to the 



galactic system 40 



The mean errors in the moments of the second order 44 



The moments of higher order 45 



CHAPTER IV. 



A treatment of proper motion and radial velocity in common 49 



General formulae for determining the apex direction and related constants 50 



CHAPTER V. 



The moments of the second order from proper motion and radial velocity observations 60 



