VARIATION OF THE SOLAR DIAMETER FROM SOLAR ECLIPSE OBSERVATIONS, 1715-1991

The diameter of the Sun may be measured at the time of a solar eclipse . We have performed an exhaustive search of the astronomical literatur e to find all existing observations of solar eclipses suitable for thi s purpose. We have also taken new observations by new techniques. We h ave undertaken a project to reduce them systematically, and in an auto mated, self-consistent way. This will produce determinations of the so lar radius at the times of solar eclipses from 1715 to the present, Re -reduction, using newer ephemerides, of observations made in 1984 show s that the component of the residuals caused by the ephemeris is subst antially reduced. This paper summarizes the research plan, outlines th e detailed astronomical features included in the calculations, and pre sents the results available.