hy the Precession of the Equinoxes, 311 



usual circles of the sphere in red inJc, to distinguish the system 

 of the ecliptic from that of the equator. It is from these few 

 circles that I propose to explain the principal phenomena of 

 geology and physical geography. 



If we now look at our globe, we shall find that the solstitial 

 colures divide the two great continents ; all is ocean in their 

 lines from pole to pole, if we except a small portion in the 

 vicinity of Kamtschatka ; and this, we may observe, is the 

 natural effect of the earth's motion in its orbit on those 

 poles. 



We next discover that the magnetic needle points to the 

 pole of l5ie ecliptic, and also that its dip corresponds with the 

 altitude of that pole ; and we can hence explain why the dip 

 varies in different places situated in the same parallel of lati- 

 tude. We shall see in the sequel why the magnetic pole is in 

 the immediate vicinity of that of the ecliptic. 



As the pole of the equator performs half its revolution in 

 12,960 years, the present place of the pole will in that time 

 be in the latitude of 43° 4-^, or that of the south of France; 

 and we find from the globe that at one period — 



Kamtschatka is in lat. 56° 30'; at another in lat. 9° 34' 



We perceive that the Ural Moimtains, in which such 

 precious mines have been discovered, were formerly in the 

 latitude of Mexico ; and it is a curious coincidence that the 

 Baron de Humboldt, on his visit to the Ural Mountains, was 

 so struck with the similarity of their physical structure to 

 those of Mexico, that he suggested a search for diamonds, 

 which was crowned with the success he anticipated. 

 . We can now satisfactorily account for the I'emains of 

 tropical animals being found in the polar regions, and why the 

 same fossils are found in the higher latitudes of the two con- 

 tinents *, and not in the equatorial regions. 



The next subject to which I shall solicit your attention is 

 the deluge. As nearly all within the polar circle is ocean, on 

 whatever point the pole of the equator may be, a circle round 



* By the globe we find that all these countries are nearly in the same 

 degrees of ecliptical latitude. 



X 4 



