Some of the more important results which were arrived at by Mallet from 5,879 observations made in the northern hemisphere, and 223 in the southern hemisphere, may be expressed as follows:—
| Maxima | Minima | |
|---|---|---|
| Northern Hemisphere | January, also a slight rise in August and October | May, June, and July |
| Southern Hemisphere | November, also May and June | March, extending over one month, also August |
Julius Schmidt, of Athens, who so carefully examined the earthquakes of eastern Europe, came to the following conclusions:—
For the earthquakes between 1200 and 1873, a maximum on September 26 and January 17; a minimum on December 3 and June 13.
For the earthquakes between 1873 and 1874, a maximum on March 1 and October 1; a minimum on July 7 and December 15.
For all the earthquakes of eastern Europe, a maximum on January 3; a minimum on July 8, or there was a maximum at perihelion and aphelion.
When the months are grouped together according to the seasons, spring, summer, autumn, and winter, we find that in the northern hemisphere the minimum is in summer and the maximum in winter, whilst in the southern hemisphere (giving the proper months corresponding to its seasons) we find two maxima, one at the commencement of winter, and the other at midsummer, whilst the minima are in spring and autumn.
Fig. 36.—Curves of Monthly Seismic Intensity (Mallet).
In the following table the difference in the number of earthquakes felt at different seasons is given more in detail.