Many are the attempts that have been made to discern some law in the occurrence of earthquakes, and to trace the influence of the sun, the moon, or even of the planets as a cause, if partial, of their origin. Many patient investigators have discovered, or thought they have discovered, periods of fluctuating seismic activity, varying in length from semi-diurnal to annual or even longer, but so conflicting have been their conclusions that little weight can be, or has been, attached to the results of their calculations; and one of the most industrious of all these investigators, the Commandante de Montessus de Ballore, has declared his conviction that no periodicity can be detected, and that the causes of earthquakes are purely terrestrial and in no way affected by any celestial body. Yet, in spite of this, the attempts and the calculations go on, and one of the most recent of these is a discussion by Herr M. Becke of some three hundred earthquakes recorded in the region round Karlsbad between 24th October and 25th November, 1897.