  We prove formulas for the number of Jordan blocks of the maximal size for
local monodromies of one-parameter degenerations of complex algebraic varieties
where the bound of the size comes from the monodromy theorem. In case the
general fibers are smooth and compact, the proof calculates some part of the
weight spectral sequence of the limit mixed Hodge structure of Steenbrink. In
the singular case, we can prove a similar formula for the monodromy on the
cohomology with compact supports, but not on the usual cohomology. We also show
that the number can really depend on the position of singular points in the
embedded resolution even in the isolated singularity case, and hence there are
no simple combinatorial formulas using the embedded resolution in general.
