of the Surface of the Earth. 107 



been found of an enormous ostrich-like bird (Owen's Dinor- 

 nis), which is nearly related to the Apteryx of the present 

 day' and is but little connected with the Dodo of the island 

 of Rodriguez, so lately become extinct. 



The present configuration of the continents probably owes 

 its elevation above the surrounding seas chiefly to the erup- 

 tion of quai-tziferous porphyries ; an eruption which affected 

 so powerfully the first great terrestrial flora,— that flora which 

 afi'orded the material for coal. What we term the plains of 

 continents, are only the broad ridges of hills and mountains, 

 whose bases are situated at the bottom of the sea. Every 

 plain is, according to its submarine relations, a table-land, 

 whose inequalities are concealed by new sedimentary for- 

 mations deposited in a horizontal position, and by alluvial 

 matter. 



Among the general considerations belonging to the extended 

 view we are now taking of our globe, the first rank is to be 

 assigned to the quantity of elevated solid land which projects 

 above the sea ; and to this determination of the amount, there 

 then succeeds the consideration of the individual configuration 

 with reference to the horizontal extension (the relations of the 

 division of parts: Gliederungs-Verhaltnisse), ov with reference 

 to the perpe7idicular elevation (the hypsometrical relations of 

 mountain-chains.) Our planet has two envelopes, a general 

 one, the atmosphere, an elastic fitiid ; and a particular one, 

 only locally distributed, which bounds the solid land and 

 thus aff'ects its form, viz., the sea. Both envelopes of our 

 planet, the air and the sea, form a natural whole, which gives 

 rise to the diversity of climate of the earth's surface : accord- 

 ing to the amount of the relative extent of sea and land, the 

 horizontal division {Gliederung) and position of the solid land, 

 and the direction and height of the mountain chains. It re- 

 sults from this knowledge of the mutual action of the air, 

 the sea, and the land, that great meteorological phenomena 

 cannot be understood, if separated from geognostical consi- 

 derations. Meteorology, like the geography of plants and 

 animals, has only begun to make progress since observers 

 became convinced of the mutual dependence of the funda- 

 mental phenomena. The word climate no doubt means, in 



