Discussion

Abstract

Hopmann: I wish to make a comment regarding the period of the libration phenomena. We have indications that the solution of the Euler equations may have terms of periods in the neighborhood of five to twenty years. This means that if we wish to establish the amplitudes of these terms it is necessary to cover with observations at least one period, or even better, a few periods. For this reason we have to make use of the old heliometric observations in the way professor Kozieł did. — Another thing that comes to my mind is the outcome of professor Kozieł’s work over more than three thousand observations made during the span of half a century. Since all this material has resulted in an error of 0″.25 for the height of Mösting A, I believe that we cannot expect much more for other points measured only a few times on photographs taken only recently.