Mittlere Kurven der elfjährigen und achtzigjährigen Zyklen der Sonnentätigkeit

Curves showing the mean course of solar activity in 11‐year cycles with very low, low, high, and very high maxima and in 80‐year cycles with weak, moderate, and strong ascent or descent, respectively, are constructed. Their construction is based on the annual Wolf numbers from 1698 until 1964 and on the secularly smoothed values of Schove's auroral numbers for each decade from 331–340 until 1891–1900. The remarkable difference between the behaviour of the 11‐year cycles, on the one side, and the 80‐year cycles, on the other side, becomes quite evident from these curves. If Kopeck's interpretation of the 11‐year and 80‐year cycles is accepted, it follows that the rate of formation of the spot groups varies in an entirely other manner than their average life‐time.