120 Baron Alexander von Humboldt on the Physiogno y 



the submersion of a considerable portion of the north-west 

 of Europe, and for the outlines of its coast presenting an 

 entirely different configuration from their present one. The 

 sinking and rising of the solid and liquid portions of the 

 surface of the earth, which are so opposed to each other in 

 their individual operations, that the rising of the one pro- 

 duces the apparent sinking of the other, are the cause of 

 all the changes of the form of continents. In a general 

 view of physical facts, and in an unbiassed and not one- 

 sided statement of natural phenomena, the possibility at 

 least of a diminution of water, or of an actual sinking of 

 the level of the sea, must be mentioned. It cannot be 

 doubted, that, during the former elevated temperature of the 

 surface of the earth ; during the existence of the power of 

 engulphing water, which must have been the consequence of 

 the occurrence of a larger amount of open fissures ; and dur- 

 ing the continuance of an entii'ely different constitution of 

 the atmosphere ; great changes must at one time have taken 

 place in the level of the sea, — changes which were dependent 

 on the increase or diminution of the liquid on the earth. In 

 the present state of our planet, however, there has hitherto 

 been an entire absence of direct proofs of a real continued 

 diminution or increase of the sea ; and there is also an ab- 

 sence of evidence of gradual changes in the mean height of 

 the barometer, at the level of the sea, at the same points of 

 obsei'vation. According to the observations of Daussy and 

 Antonio Nobile, an increase of the height of the barometer 

 would of itself produce a lowering of the level of the water. 

 As, however, the mean pressure of the atmosphere at the 

 level of the ocean is not the same in all latitudes, owing to 

 meteorological causes arising from the direction of the wind 

 and from moisture, the barometer alone would not afford 

 sure evidence of an alteration of the level of the sea. The 

 important observations, according to which some sea ports 

 in the Mediterranean were, at the beginning of this century 

 repeatedly laid dry for periods of many hours, seem to prove 

 that a local retirement of the sea, and a permanent drying 

 up of a small portion of the coast, can be produced by a 



