Physical Features of the Australian Alps. 101 



distant from the most southern prolongation of the Dividing 

 Range, at the head of the Livingstone Creek, and probably 

 to the degrading and eroding influence of southerly and 

 south-westerly moisture-laden winds, the southern slopes 

 are steeper than those within the northern basins. This is 

 more especially the case with the Mitchell and Mitta Mitta 

 basins, the former having a more rugged and serrated surface 

 configuration than the latter, which is more undulating and 

 rounded. 



Recent observations made by me at Omeo for Mr. Ellery, 

 when compared with records of rainfall at Grant, which is in 

 the centre of the Mitchell basin, give interesting results, at 

 Omeo that for 1880 being 29'92 inches during 114 days, and 

 for same period at Grant 58*59 inches during 154 days. This 

 difference of 38*67 inches, although slightly affected by 

 elevation (Grant being 3700 feet above sea level, and Omeo 

 2108 feet), is, I think, still due to the following causes: — 

 That as the principal rainfall at Omeo is brought by 

 southerly and south-westerly winds from the Southern 

 Ocean, these moisture-laden winds are deprived of their 

 aqueous matter by condensation south of and along the crest 

 of the Dividing Range, and are then raised into the higher 

 regions of the atmosphere, from which they are attracted by 

 the higher peaks and plateaux ; there, by the action of colder 

 currents of air or electric forces, re-condensed, and deposited 

 in the form of snow. Were the surface within the Mitta Mitta 

 basin as much subjected to the action of heavy deluges of 

 rain as that of the Mitchell appears to be, it is probable that 

 the river valleys of the former would be more deeply cut 

 into gorges by erosion, and the peaks present a more splin- 

 tery outline than they do at present, owing, in a great mea- 

 sure, to the petrological characteristics of the area — crystal- 

 line schists, which, as I understand, have a tendency to 

 weather into sharper outlines than their unaltered congeners, 

 the Silurian rock masses occurring in the Mitchell basin. If 

 this view be correct, the undulating and rounded outlines of 

 the ranges within the Mitta Mitta basin would probably 

 result from the more gradual disintegration of the rock 

 masses by frosts and snows. The more important charac- 

 teristics of the source basins comprised within the area 

 indicated at the commencement of this paper are as follows: 

 — The Indi, although unimportant commercially, is still inte- 

 resting from a topographical and geological point of view. 

 Forming the head waters of the Murray River, some of its 



