Factors controlling the atmospheric conductivity at the Huancayo Magnetic Observatory

Some of the results of four months, recordings of atmospheric‐electric elements at Huancayo are presented. Positive small‐ion mobility appears to be constant, whereas negative small‐ion mobility has a regular diurnal variation. Positive small‐ion density is found to follow the normal equation of small‐ion balance. Values of combination‐coefficients are deduced. A mechanism for the origin of variations in conductivity has been suggested by Gish. In general the results in this paper are in agreement with this suggestion. In the case of intermediate ions, a daily variation in mobility‐distribution is found, which suggests a source of intermediate ions close to the place of measurement.