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CHAPTER XXIV. 



ON THE ANCIENT TEMPERATURE OF THE EARTH. ON CENTRAL 



HEAT, AND ON ASTRONOMICAL PHENOMENA ILLUSTRATIVE OF 

 GEOLOGICAL THEORIES. CONCLUSION. 



It is now generally admitted by geologists, that the temperature 

 of the earth was, at a former epoch, at least in northern latitudes, 

 much higher than at present. The facts on which this opinion is 

 founded are very numerous, but they are dependent chiefly on the 

 organic remains found in a fossil state. The animal remains of the 

 large mammalia, such as the elephant, the rhinoceros, and hippopo- 

 tamus, are abundant in some of the tertiary and diluvial beds. The 

 bones and teeth of elephants in Siberia, and the borders of the Icy 

 Sea, are so numerous, that it is evident the animals must once have 

 existed in immense multitudes in these high latitudes. On the Oys- 

 ter Bank, ofF Hasburgh, on the Norfolk coast, many hundred grind- 

 ers of elephants have been found, and a vast quantity of their bones. 

 (S. Woodward's Syn, Tab.) Teeth of the elephant have also been 

 found in almost every county in England, and in all the northern 

 kingdoms of Europe. Remains of lizards of enormous size occur 

 in many of the English strata : these animals, in a peculiar manner, 

 seem to require a high temperature for their full development. 



The fossil remains of vegetables prove the high temperature of 

 the countries in which they flourished, more decidedly than animal 

 remains. ^ Fossil trunks and leaves of the palm tree, the tree-fern, 

 and of gigantic reeds, analogous to what are now growing in equa- 

 torial climates, abound in the coal strata of northern latitudes. It 

 may be objected, that the large mammalia, (such as the elephant or 

 hippopotamus,) belong to the order of Pachydermata, or thick-skinned 

 animals, and like the pig, which belongs to that order, might be con- 

 stituted for living both in polar and equatorial regions. Indeed, it is 

 known, that some of the fossil elephants had a covering of hair or 

 wool, which must have been intermixed as a defence against cold. 

 A race of elephants with shaggy hair, (according to Bishop Heber,) 

 inhabit the cool regions of the Himmalaya Mountains. From the 

 remains of these large mammalia alone, we could not therefore prov© 

 the high former temperature of northern laitudes. But these ani- 

 mals would require a constant supply of food throughout the year 

 which they could scarcely obtain in a frozen climate ; and when we 

 farther observe, that the vegetation of the ancient world was analo- 

 gous to the vegetation of the warm regions which the elephant and 

 the rhmoceros now chiefly inhabit, we can scarcely refuse our assent 

 to the position, that the temperature of the earth at a former period 



