ABSTRACT
Solar Faculae: yearly average values in millionths of the area of the visible surface of the sun, corrected for foreshortening
years and decimals. Thus, 1745·0 means the beginning of 1745. BAUR (1964) has published tables of successive monthly values from 1749 to 1962 of
the 9-and 17-month average sunspot numbers derived from the Ziirich data. These are very nearly averages over 10 and 19 rotations of the sun respectively; they correspond more nearly to whole rotations than the conventional smoothings (e.g. 5-and 13-month averages). The dates of the various sunspot maxima and minima since 1749 appear slightly shifted by this calculation, but differ on average only by 0·1 year from those given here in Table App. 1.3. B A U R gives (loc. cit.) a table of the dates derived of sunspot maxima and minima and of the divisions of each cycle since 1749 into septiles of the rising and falling phases, for convenience in relation to significant associations noted with the behaviour of the large-scale circulation of the atmosphere.
