  In this paper we study periodic variability of the magnetic field in the Ap
star 33 Lib. We found that its most probable period equals 83.5 years. There
exist also possible shorter periods: 11.036 days, 7.649 days and 4.690 days.
Analysis of the magnetic behavior of 33 Lib allows us to conclude, that the
star shows the second longest period the slow rotator gamma Equ, the latter
star with the period of 97 years.
