AGE OF COAL. 227 



much as it is at the present time. Here, then, there was 

 in the air a large surplus of one of the three materials 

 of which plants are chiefly composed, and it was appro- 

 priated in producing the profuse vegetation. And as 

 this vegetation was for the purpose of making coal, we 

 may say that the material for the coal was kept in the 

 atmosphere in a gaseous state, by being combined with 

 oxygen, until the earth, during a lapse of long ages, was 

 put into a fit condition to bring forth an exuberant veg- 

 etation. When this was effected the Creator introduced 

 the requisite plants, and the transfer was made from the 

 atmosphere through them to the coal-measures. Such 

 a transfer from the gaseous to the solid state of such a 

 quantity of matter seems at first thought strange, but it 

 is no more so than the transformation which we see con- 

 tinually in the case of water. This rises in the vaporous 

 or gaseous state into the atmosphere by evaporation, 

 and anon we see some of it again in the shape of solid 

 ice on the surface of the earth. 



327. Climate of the Carboniferous Age. The climate 

 of the earth was very different in that age from what it 

 is now. It was warm in all quarters, and very equally 

 so. We know this because we find very widely distrib- 

 uted the remains of plants and animals similar to those 

 which now flourish in warm climates. The climate was 

 so warm in the arctic regions that rank vegetation was 

 present there, and coal was laid down. With such prev- 

 alent warmth there must have been great moisture in 

 the air, and this favored rank growth, notwithstanding 

 there probably was from this moisture less of clear sun- 

 shine than there is now. 



328. Carboniferous Scenery. Though the vegetation 

 of that age was so rich, the scenery was tame and mo- 

 notonous. Forests, with their tangled undergrowth, 

 mostly swampy, spread over vast platforms, in some 

 cases almost continental in extent. There were no such 

 elevations as we see at the present day to relieve the 



