In this paper a classification of
the manifolds obtained by a (p,q) surgery along an (r,s) lorus knot is given. If
|σ| = |rsp + q|≠0, then the manifold is a Seifert manifold, singularly fibered by simple
closed curves over the 2-sphere with singularities of types α1= s,α2= r, and
α8= |σ|. If |σ| = 1, then there are only two singular fibers of types α1= s,α2= r,
and the manifold is a lens space L(|q|,ps2). If |σ| = 0, then the manifold is not
singularly fibered but is the connected sum of two lens spaces L(r,s)#L(s,r). It is
also shown that the torus knots are the only knots whose complements can be
singularly fibered.
