236 



subject, he stated some of the principal conclusions that the 

 discussion of the facts by the method of curves warranted. 



The records of earthquakes become more and more nume- 

 rous as navigation and travel have, in the course of time, be- 

 come extended, though it is not probable that the actual 

 number of earthquakes occurring at a remote antiquity was 

 less than now. 



Their extreme frequency, during the last two or three cen- 

 times, since the attention of mankind has been alive to the 

 record of such phenomena, and intercourse has been more per- 

 fect, is such as fully to warrant the position of the author's 

 first Report, that no day passes without one or more; and 

 that they are the indices of a constantly and pretty uniformly 

 present, cosmical force; "the re-action of the interior of the 

 planet upon its exterior " having, however, epochs of greater 

 disturbance and epochs of repose. 



The peculiar features of the curves exhibited to the Aca- 

 demy were shown, and of the secondary deduced curves of 

 maxima, &c, as also the deduced curves, showing the dis- 

 tribution of earthquakes with reference to seasons and months. 

 These seem to indicate a preponderance in the winter months ; 

 but the author is disposed to view this result as accidental, 

 although agreeing with the deduction of M. Perrey from his 

 much more limited base of induction. 



The author also exhibited and explained his large Chart of 

 the World, on Mercator's projection, on which the distribu- 

 tion of earthquakes in space is laid down from the Catalogue, 

 and, by a peculiar system of colouring, the relative intensity 

 and area of disturbance, and the number or reduplication of 

 shocks also indicated, for every locality over the whole explored 

 surface of the earth. 



He pointed out the results which this map indicated, and 

 the differences between it and the maps of Johnston and 

 Berghaus. 



The largest habitually convulsed area now on the earth's 



