The use of solar eclipse timings to compare the reference systems of Newcomb's Tables of the Sun and of the Improved Lunar Ephemeris

Photoelectric, photographic, and visual observations of second and third contacts of the total solar eclipses of 12 November, 1966 and 7 March, 1970 are analyzed. The observations indicate a difference in the reference system of Newcomb's Tables of the Sun as compared to the reference system of the Improved Lunar Ephemeris (J = 2) of 0^s.911 ± 0^s.034 m.e. The correction is to be applied in the sense of reducing the value of T as tabulated in the American Ephemeris when interpolating the position of the Moon.