  The tachyon-free nonsupersymmetric string theories in ten dimensions have
dilaton tadpoles which forbid a Minkowski vacuum. We determine the maximally
symmetric backgrounds for the $USp(32)$ Type I string and the $SO(16)\times
SO(16)$ heterotic string. The static solutions exhibit nine dimensional
Poincar\'e symmetry and have finite 9D Planck and Yang-Mills constants. The low
energy geometry is given by a ten dimensional manifold with two boundaries
separated by a finite distance which suggests a spontaneous compactification of
the ten dimensional string theory.
