Cycles in Natural Phenomena

Abstract

IN December 1922, Dr. Merriam, president of the Carnegie Institution of Washington, called a conference to discuss the question of ‘cycles’. The report of this, and of a second conference held in December 1928, have now been published by the Carnegie Institution,¹ and the two reports form a stimulating contribution to the subject. The members took a very broad view, which was set out by F. E. Clements in an introductory paper as follows: “It seems desirable to use cycle as the inclusive term for all recurrences that lend themselves to measurement, and period or periodicity for those with a definite time interval, recognising, however, that there is no fixed line between the two. On this basis there can be no question of the existence of climatic and other cycles, though there may be the gravest doubt of the reality of periodicities in climate beyond that of the year.”