A transfer function F between a measure of the solar activity S and the 11-year cosmic ray intensity modulation I0--I is determined for the two sunspot cycles 19 and 20. For S we used the monthly occurrence of major flares, all flares, sunspots and ssc's. In agreement with D. J. Hatton [1980> and G. A. Bowe and D. J. Hatton [1982>, we find a well-behaved transfer function for both major flares and all flares. It is a damped pulse with duration of 16 and 13 months for the major flares and all flares, respectively. These figures are significantly longer than that of 10 months obtained by Bowe and Hatton.