15 
sea, while many of the spurs, ridges, and isolated peaks would 
appear as chains of islands, and very abrupt islands separated 
from the main by narrow and deep channels. The peaks and 
higher mountains would be small precipitous islands, and there 
would be groups of them where a cluster of hills formerly 
existed. Now, this, in brief, is a precise description of the 
north-eastern coast. The islands are just as described — ridges 
and spurs from the Main Eange, which were formerly its 
precipitous peaks and crests, the deep valleys now represented 
by ocean channels of bold water. 
If we examine the nature of the rocks we shall find the 
evidence still stronger. The rocks are those of the Main 
Eange in every particular. Granite is the most abundant, as it 
is more common in the northern islands than in the south. 
The nearer the islands are to the shore the more granitic they 
are, while the outliers are often composed of highly-inclined 
metamorphic schists and slates. There are exceptions to this, 
however ; just as we find on the Main Eange the grauitic or 
metamorphic portions as much exposed on the coast as in the 
centre of the axis. Finally, if we take a glance at the whole 
aspect of the north-eastern coast line we shall be forcibly 
struck by its resemblance to a range of mountains round which 
the sea has arisen. Any one who has witnessed the effect of a 
high tide on a very rocky coast, especially in places where the 
rise and fall is considerable (Jersey, for instance) will be struck 
by the resemblance it presents to the island coast line of 
north-east Australia. 
From this, therefore, we may conclude that the coast range 
of Northern Australia, or the northern portion at least of the 
great divide, was formerly much higher than it is now. AVhat 
the amount of subsidence has been, there is not knowledge 
enough of its character to form an opinion. There is no part of 
the channel between the main land and the Barrier Eeef which is 
over 200 feet deep. An upheaval to this extent would lay bare dry 
land between all the islands and the main, as far as the Barrier. 
To raise all the reef itself, an elevation of 2,000 feet would at 
least be required, and probably even more. On the other hand, a 
subsidence of 3,000 feet or more would be required to submerge 
all the islands. Mount Stafforth and other mountains on 
Ilinchinbrook Island are over 3,000 feet high, Cape Gloucester, 
2,000, &c. Such a subsidence would submerge the whole of the 
Dividing Eange, with the exception of a few mountains, such as 
the Bellenden Ker Eange, Mount Feter Botte, and a few 
others. If the subsidence has been equal, and the depth of the 
Barrier Eeef be any indication of its extent, then the Dividing 
Eange must have been over 7,000 feet high in some places, and 
we might expect to find in extremely high portions of the range 
some evidence of glacier action. The river channels may also be 
expected to furnish evidence of their greater elevation. The 
large proportion of Asiatic species of plants in the flora of the 
northern divide certainly points to some more intimate con- 
