CLYDE J. BOLLINGER, Unlversltr of Oklahoma, Norman It, as appears certain, terrestrial climatic fluctuations are infiuenced by variations in the solar energy reaching the earth; and, if also, the more or less accepted theory is accepted that sun-spot activity is influenced by planetary configuration, the conclusion that climatic fluctuations are influenced by planetary configuration. is inescapable. Configuration recurrences of Venus, Earth and Jupiter at intervals of 11.1928696 years, 22.385739 years, 4~ 771478 years,. 89.542966 years and 179, 086912 years are here described. These periods are derived from the siderial and mean synodic periods of the planets, which are astronomic constants.