  We study the three-dimensional quantum Ising spin glass in a transverse
magnetic field following the evolution of the bond probability distribution
under Renormalisation Group transformations. The phase diagram (critical
temperature $T_c$ {\em vs} transverse field $\Gamma$) we obtain shows a finite
slope near $T=0$, in contrast with the infinite slope for the pure case. Our
results compare very well with the experimental data recently obtained for the
dipolar Ising spin glass LiHo$_{0.167}$Y$_{0.833}$F$_4$, in a transverse field.
This indicates that this system is more apropriately described by a model with
short range interactions than by an equivalent Sherrington-Kirkpatrick model in
a transverse field.
