1906 J 



SEE— THE CAUSE OF EARTHQUAKES. 

 Fig. I. 



279 



Mt. Pelee. The burning cloud of December 16, 1902, seen from the sea. 

 (From the Belgian Astronomical Society, tenth year. Plate V.) 



heated rocks quite near the surface, zvhile the crust is fractured 

 and leaky everyzvhere, and especially zvhere the depth of the sea is 

 greatest. The sea covers three-fourths of the earth's surface, and 

 earthquakes are found to he most violent zvhere the sea is deepest, 



PROC. AMER. PHIL. SOC., XLV. 184 R, PRINTED FEBRUARY 1 9, I907. 



