138 



for each Earthquake on record, and even for each shock of which 

 Earthquakes may consist — a work of vast labor. 



" M. Perrey has tabulated all the Earthquakes recorded since 

 1801, and 'by discussing the catalogues which he has formed, 

 shows by three ways, independent of one another, the influence 

 of the course of the moon on the production of Earthquakes,' 

 viz : — 



1st. " That the frequency augments on the syzygies." 



2d. " That the frequency augments in the vicinity of the 

 moon's perigee, and diminishes towards the apogee." 



3d. " That the shocks of Earthquakes are more numerous 

 when the moon is near the meridian, than when 90 degrees 

 from it." 



But in each of these results, he finds some " minor " and some 

 " large anomalies." 



Some years since, Mr. Stodder read before this Society a paper 

 on the Changes of the Surface of the Earth, In this paper he 

 proposed the hypothesis, that the centrifugal force of the diurnal 

 rotation of the earth, acting on the fluid interior mass (if such is 

 the condition of the interior) of the earth, was the cause of Earth- 

 quakes, and that if there has been any change in the position of 

 the poles of the earth, that the centrifugal force, which gives the 

 earth its spheroidal form, in changing the form of the earth to 

 correspond with the new position of the poles, is sufficient to 

 account for all the geological phenomena of the fracturing of 

 strata, elevation of mountain chains, &c. ; and that no other cause 

 has yet been assigned, that is adequate to such effects. This 

 paper, he supposed, has failed to convince any geologist of the 

 soundness of the arguments it presented, and had probably been 

 forgotten by those who heard it. For himself, he had, as yet, 

 seen no reason to change his views, as then set forth ; the pro- 

 gress of geological science, investigation, and discovery, had 

 produced no new arguments against the hypothesis, and he had 

 met with nothing of essential importance in its favor, to be added 

 to the original reasoning, until he saw the article from which he 

 read the above extracts. The fundamental idea of the hypothesis 

 of Mr. Stodder and that of M. Perrey is the same, viz : that the 

 mobility of the internal mass of the globe plays a part in the 



