  We study the ground state phase diagram and the critical properties of
interacting Bosons in one dimension by means of a quantum Monte Carlo
technique. The direct experimental realization is a chain of Josephson
junctions. For finite-range interactions we find a novel intermediate phase
which shows neither solid order nor superfluidity. We determine the location of
this phase and study the critical behaviour of the various transitions. For
on-site interaction only, we map out the phase diagram as a function of the
hopping strength and the chemical potential.
