A graphical format has been adopted to depict some characteristic variations associated with the solar activity cycle up to 1988, for both the Zurich annual and monthly mean values over the respective periods from 1700 and 1750. Both low pass and band pass filtering techniques have been employed to smooth the data, the autocorrelation coefficients determined for a high number of lags to illustrate the secular modulation of the maximum values in each cycle and the spectral amplitudes computed to establish periodicities in the chronologies.