  Conventional explanations for observations of anomalous behaviour of
mechanical systems during solar eclipses are critically reviewed. These
observations include the work of Allais with paraconical pendula, those of Saxl
and Allen with a torsion pendulum and measurements with gravimeters. Attempts
of replications of these experiments and recent gravimeter results are
discussed and unpublished data by Latham and by Saxl et al. is presented. Some
of the data are summarized and re-analyzed. Especially, attention is paid to
observations of tilt of the vertical, which seems to play an important role in
this matter and recommendations for future research are given. It is concluded
that all the proposed conventional explanations either qualitatively or
quantitatively fail to explain the observations.
