10 
Geology and Physical Geography : 
considerable length of the Main Divide, extending from north of 
Ballarat to the Grampians. The Glenelg River, rising in and 
skirting the northern slopes, flows round the western extremity 
of the Grampians, and after being joined by the Wan non, which 
receives their southern drainage, enters the sen at the 141 at 
meridian, or western boundary line of the colony. Several unim- 
portant streams empty themselves at various points along the 
coast, between the mouths of the Glenelg and the Hopkins. 
North of the Cape Otway Ranges, and between the water-sheds 
of Curdie’s River, the Gellibrand, the Hopkins, and the Leigh 
Rivers, is a district containing numerous Jakes, salt and fresh. 
The largest of these, and also the most extensive in Victoria, 
is Lake Korangamite, a salt lake situated in a large central depres- 
sion, about 350 feet above sen-level. Lake Korangamite receives 
the drainage of nearly 1,200 square miles, but has no outlet save 
by evaporation. It lias been remarked of the lakes in this district 
that those with no outlets are salt, while those having outlets are 
fresh. The explanation is that in the former the salt brought by 
rain-waters from the soil of the surrounding country has no means 
of escape, while in the latter it is carried away in solution, and thus 
does not collect in sufficient quantity to affect the taste of the water 
Many of these lakes are the craters of now extinct volcanoes. 
Briefly recapitulating, we have, as the leading mountain features 
of Victoria:— 1st. The Main Divide, and its branch systems of 
ranges. 2nd. The South Gippsland and Western Port Ranges, of 
which portion of the Southern Spur constitutes the leading ridge, 
and which are only slightly connected with the Main Divide by 
means of the low u saddle ” to which the Southern Spur descends, 
near Drouin. 3rd. The Cape Otway Ranges, totally unconnected 
by any leading ridge with the Main Divide, and occupying a great 
southern projection of the land westward of the meridian of Port 
Phillip, as t lie South Gippsland and Western Port Ranges occupy 
a similar projection eastward thereof. As the principal groups of 
drainage systems we have — 1st, that of the Murray, north of the 
Main Divide ; 2nd, the South-eastern or Gippsland systems, south 
of the Main Divide, and east of the Southern Spur : 3rd, the 
South-western systems, or those south of the Main Divide and 
west of the Southern Spur. 
The foregoing description of the principal mountain and river 
systems has been given somewhat minutely, as I wish hereafter to 
show how the present physical structure of Victoria is due to a 
complication of causes, in the form of geological changes, which 
have been incessantly at work since the remotest epochs. An 
attempt will also be made to indicate the comparative relations of 
the sea and land surfaces, and the positions and courses of the 
principal drainage channels, during various eras in the geological, 
history of this country. 
