i9o6] SEE— THE CAUSE OF EARTHQUAKES. 359 



explanation of such phenomena as the coal measures, gives us a 

 simple and natural way of explaining leading phenomena of the 

 strand. We have elsewhere explained why the movements of faults 

 must be attributed primarily to the formation of steam-saturated 

 lava at the depths whence earthquakes originate. 



The steam which induces this movement naturally remains hidden 

 in the earth, and as the process goes on uninterruptedly from one 

 geological age to another, there is a gradual secular desiccation of 

 the waters of the sea, and a correspondingly slow lowering of the 

 strand line. 



To determine the average rate of this lowering of the strand we 

 would have to take a figure somewhat smaller than that found in the 

 different countries since a given geological epoch, and even then, 

 the result would be partly vitiated by the effects of secular elevation 

 of the land. In any case, the movement depending on secular desic- 

 cation of the oceans is extremely slow. 



This view that there is a secular desiccation of the waters of the 

 sea is not new, but was entertained in different forms by Benoist de 

 Maillet (1692), Celsius (1743), Von Hoff (1822), Goethe and 

 others (cf. Suess, " Face of the Earth," Vol. II, Ch. I). 



Professor Suess' exhaustive discussion of the movements of the 

 strand line will be found chiefly in chapters XII-XIV of Volume 

 II of the " Face of the Earth." He considers the lowering of the 

 sea level to the extent of hundreds of meters within recent geo- 

 logical time to be proved. The cause here suggested gives the only 

 explanation of the phenomenon which seems at all probable or 

 consistent with known facts. 



§ 37. On the gentle movements of the land. 



In many parts of the world, the rocks are comparatively un- 

 broken, and leakage is very slow and gradual. This may corre- 

 spond to the beds of shallow seas or to the land when level and 

 unbroken by mountains. In all such regions the water which may 

 seep down would give rise to a very evenly diffused subterranean 

 steam pressure and the chances are that any movement which might 

 take place would prove to be very slow and gradual. The strain 

 being nearly equalized at all points, there would be no heaving re- 

 quired to adjust the nearly even balance of the forces, and conse- 



PROC. AMER. PHIL. SOC., XLV. 184 W, PRINTED FEBRUARY 23, I907. 



