AbstractThe mean radiant of the Geminid meteor stream and its diurnal motion are determined from 118 visual radiants. The visual radiant at maximum (⊙ = 260°.6, 1950.0) lies at right ascension 112°.02, declination + 32°.00. The total daily motion is 47′ eastward. The visual radiant and motion agree well with the photographic data, but not with the radar.An activity curve is derived from 124 nights' observations. A rise to a sharp maximum and a rapid decline are shown. The stream is detectable over a 10‐day interval: the minimum visual stream‐width is about 2.3 × 107km. Some physical characteristics of the meteors also ar