A REVISED LISTING OF THE NUMBER OF SUNSPOT GROUPS MADE BY PASTORFF, 1819 TO 1833

J. W. Pastorff of Drossen, Germany, made about 1477 observations of su nspots between 1819 and 1833. These observations were erroneously inte rpreted by A. C. Ranyard in 1874 and then used by Rudolf Wolf in his c alculations of the Wolf Sunspot Numbers. The result is a noisier daily time series and overestimation of the monthly and yearly means for th ese years. Pastorff was actually a very good observer. In this paper, Pastorff's original observations are reexamined and more nearly correc t values for the number of sunspot groups are tabulated. We show some examples of the problems created by Ranyard's interpretation and the c onsequences for the history of solar activity that a correct interpret ation of Pastorff's observations will have. Pastorff's observations pr ovide valuable information on the first strong cycle after the Dalton Minimum (1795-1823).