A purely combinatorial compactification of the configuration space of n(gre
ater than or equal to 5) distinct points with equal weights in the real pro
jective line was introduced by M. Yoshida. We geometrize it so that it will
be a real hyperbolic cone-manifold of finite volume with dimension n - 3.
Then, we vary weights for points. The geometrization still makes sense and
yields a deformation. The effectivity of deformations arisen in this manner
will be locally described in the existing deformation theory of hyperbolic
structures when n - 3 = 2, 3. (C) 1999 Elsevier Science Ltd. All rights re
served.