In an attempt to elucidate the daily fluctuations seen in the 1980 drift time data (August 30-September 13) and to monitor the solar diameter for an interval as long as possible, visual drift timing observations were made on 46 consecutive days, from May 16 to June 30, 1981. A total of 2091 visual drift times (including 11 doubtful ones) was obtained. From the observations, R(vis) is found to be 960.2 + or - 0.1 arcsec, that is, the standard value of 961.18 arcsec derived from Greenwich transits is much too large. With due weight assigned to the photoelectric observations, it is concluded that the correct value of R is 960.0 + or - 0.1 arcsec.