BY PROFESSOR STEPHENS. 529 



level, which therefore was year by year becoming more and 

 more depressed in relation to the river. The balance was from 

 time to time restored by a higher flood than usual, which found its 

 way in volume over the natural levees, formed broad sheets of 

 water in the lower grounds, and either changed the course of the 

 river as a whole, or at least put the lower grounds in the way of 

 reclamation by subsidence of mud. 



Since the shores have been denuded of their forest, the flood- 

 waters naturally flow more rapidly outwards to right and left of 

 the channel, and carry the sediment with which they are loaded 

 into the lower grounds, where it is now chiefly deposited. Hence 

 we may expect an increase of relative elevation, which, though small 

 for each year, is continuous, and may perhaps be of considerable 

 importance in another half century. The process described above 

 may be seen in every stage ; the wide and deep lake which has 

 never received its proportionate share of alluvium ; the " broad 

 water " or huge expansion of the river over a formerly separated 

 swamp, where the process of deposition is going on continuously 

 during every hour of every tide ; the dismal grey Casuarina 

 marsh, where the ground has not yet been raised above the 

 influence of the salt water ; the green freshwater swamps, with 

 their innumerable creeks and lagoons ; the low moist rich 

 meadows ; and finally the fertile and well drained sugar or corn 

 land. Thus on a small scale, and with a different flora, the 

 Clarence is even now repeating the grand natural processes to 

 which modern civilisation owes the fuel which is its power. And, 

 as we have seen, a similar chain of circumstances led ages ago in 

 the same district, to the deposit of sands and muds, and of the 

 waste and decomposing matter of ferns, palms, pandanus, and pine 

 trees which we recognise as the Clarence River Coal measures. 



Again, the hills, whether isolated or as spurs from the main 

 range, rise abruptly every where from the level ; showing that the 

 subaerial erosion, the debris produced by which tends to fill in and 

 obliterate the angle between the horizontal ground and the hill 

 slope, is more than counterbalanced by the accumulations of 

 sediment from flood waters. These are all proofs of increasing 



