Revision of the tidal acceleration of the Moon and the tidal deceleration of the Earth's rotation from historical optical observations of planets

The tidal acceleration of the Moon was first estimated by Clemence (1948) who used Spencer Jones (1939) results on the apparent accelerations of longitudes of the Sun, Mercury and Venus observed with respect to Universal time. Clemence proposed to introduce an empirical term into a purely gravitational lunar theory to account for the tidal acceleration and to conform the origin of longitudes and the time-like argument of ephemerides of planets to the ephemeris of the Moon. Morrison (1979) amended the Jones-Clemence empirical correction, and this was applied to the ILE j=2 to form the ET-UT differences by Stephenson & Morrison (1984) which are now accepted by all astronomical almanacs. Since Spencer-Jones study a large amount of optical observations of the Sun and planets have been accumulated, the non-rotating Hipparcos reference frame and the more precise integrated ephemerides of the planets have become available. With these achievements it is reasonable to revise Jones-Clemence result to compare it with the respective estimates supplied by modern techniques.