Abstract: In this paper the ICW and the FICN are studied retaining the super rotation rate of the inner core relative to the mantle and the obliquity of the inner core axis relative to the mantle axis for a simple earth model of which both the mantle and the inner core are axially symmetrical and rigid.Although the adoption of such a simple earth model does not permit to obtain more accurate results,this permits to treat the problem entirely analytically,and thus to have more insight to the nature of the problem.