Remarks on the Investigation of Climates

Abstract

TO Prof. Balfour Stewart we are indebted for the separation of meteorology into its two great divisions of physical and climatic. The latter I have proposed to separate into two sub-divisions, viz., normal and abnormal. The first of these subordinate branches includes the investigation of the usual states of the atmosphere in different parts of the earth's surface, as ascertained by periodic data derived from the averages of observations continued for a series of years. The second subordinate branch has for its object the investigation of unusual temporary disturbances of the equilibrium of the atmosphere—such, for example, as storms of wind, by means of the comparison of individual observations, extending over only a few hours or a few days.