On Lunar and Solar Periodicities of Earthquakes

In a paper recently communicated to the Royal Society “On Lunar Periodicity in Earthquake Frequency,” Mr. C. G. Knott gave some results, from which he argued that a real connexion between tidal effects and earthquakes probably existed. These results are based on a method which has frequently been employed. The records of earthquakes are grouped together and expressed by means of a Fourier series, and conclusions are based on the greater or smaller values of the coefficients of this series.