  Multi-decade observing campaigns of the globular clusters 47 Tucanae and M15
have led to an outstanding number of discoveries. Here, we report on the latest
results of the long-term observations of the pulsars in these two clusters. For
most of the pulsars in 47 Tucanae we have measured, among other things, their
higher-order spin period derivatives, which have in turn provided stringent
constraints on the physical parameters of the cluster, such as its distance and
gravitational potential. For M15, we have studied the relativistic spin
precession effect in PSR B2127+11C. We have used full-Stokes observations to
model the precession effect, and to constrain the system geometry. We find that
the visible beam of the pulsar is swiftly moving away from our line of sight
and may very soon become undetectable. On the other hand, we expect to see the
opposite emission beam sometime between 2041 and 2053.
