146 E. C. ANDREWS. 



taries are illustrated by the model, but the gulleys and 

 gorges innumerable which break up the continuity of the 

 great canon and mountain walls are not shown. Similarly, 

 only the larger hills and mountains are represented, the 

 legions of smaller elevations being merely indicated by a 

 generalised type of mildly roughened topography. Accuracy 

 of representation can only be obtained after the completion 

 of detailed topographic surveys. 



The general appearance of the New England surface, as 

 gained from a commanding eminence, has, however, been 

 illustrated, as also the general appearance of the wild 

 eastern topography afforded to the traveller as he surmounts 

 the ridges which swell out from the ravines. In the model 

 the canons and ravines are represented as limited in number, 

 whereas, in reality, the traveller is overwhelmed by the 

 wealth of branching ravines and overlapping spurs as 

 he views the jungle-laden depths from some forest-clad 

 spur or eminence. 



2. Geographical Notes. — The main topographic divisions 

 illustrated by the model are the great Plateau of New 

 England, the Ooastal Region and the Inland Plains. 



(a) The Plateau. — It is evident that the plateau must 

 formerly have had a much greater extension than it 

 possesses at present. The portion untrenched by canons and 

 ravines consists mainly of a gently warped and a maturely- 

 dissected surface, above which, in various localities, rise 

 other small plateaus. At the heads of the Namoi, the 

 Macleay and the Manning Rivers, the general plateau 

 surface is almost 4,000 feet in height, thence towards 

 Armidale it possesses a very gentle dip. At the latter 

 locality the plateau has a general height of about 3,500 feet, 

 while the average height of the broad mature valley bases, 

 which mildly roughen this level, is about 3,250 to 3,300 * 



1 All heights unless otherwise specified are referred to mean sea level 

 at Sydney. 



