...and Oppolzer. The most urgent want which the present volume supplies is that of improved methods for deriving and reducing the positions and proper motions of the fixed stars made necessary by the period of 150 years through which these positions now have to be reduced. In...

...handbook of convenient reference for the use of the working astronomer in applying methods and formulae. The most urgent want which the work is intended to...older methods are made necessary by the long period through which positions of the stars have to be reduced, and by the extension of astronomical and statistical...