366 PROCEEDINGS OF SECTION E. 



and water circulation, the higher regions of Australia offer a 

 splendid area for investigating many meterological changes. The 

 movements of circo-felum* in advance of cyclonic disturbances, 

 could be observed with greater clearness from the Alpine stations 

 free from the influence of smoke and other obstructions incidental 

 to large cities in the lowlands. The causes which predominate in 

 the deflection of extensive aerial currents, and the consequent 

 condensation and precipitation of rain, snow, &c., over the alps — 

 whether such be due to ascensional movements of moisture-laden 

 air,t to other thermal influences, or to the complex actions arising 

 from the irregular barometric depressions and nulic cyclones, which 

 are constantly moving over the earth's surface in the temperate 

 zones, J the protrusion of areas of high and low pressures, &c., 

 or other causes of like nature — would doubtless be more satisfac- 

 torily determined by establishing a chain of high-level observations 

 on the Western Australian ranges, across South Australia and 

 the summits of the Australian Alps, to the Blue Mountains in 

 New i?outh Wales. These might be expected to furnish data 

 of sufiicient scientific importance to enable our able Australian 

 astronomers to establish some valuable weather laws, or in addition 

 to determining more fully the laws of Meteorology prevailing 

 overour Australian continent, and enable them to reduce thealready 

 formulated theories of Europe and America to general laws.§ 



That the primary condition of earth sculpture is to be found in 

 the intensity of the denuding agencies is, I think, obvious : but 

 in areas where the sub-aerial denuding agencies are equal in 

 intensity, then the diflerent waste resisting powers of the diflerent 

 rock masses gradually evolve these surface contours, which after- 

 wards modify the action over certain areas of the . original 

 climatic conditions. Thus, where the hard crystalline rock-masses 

 resisting sub-aerial decay, form ridges, while the softer rock-masses 

 are degraded. The circulation of vapour and the influences of 

 such ridges in the vertical protrusion of moisture-laden winds 

 causing secondary influences which produce inequalities of rainfall 

 and other hygrometric and thermal conditions. The latter 

 again exert a modifying effect on the vegetation, so that from the 

 time when a vast table-land existed in South-east Australia, 

 until the present contours were formed by the erosion of the 

 existing valleys, the gradually changing climatic conditions would 

 slowly evolve corresponding changes in the physiogonomy of 

 the native vegetation, and tend to constant, yet imperceptable, 

 variation in specific forms. 



* Rev. Clement Ley. Quart. Journ. Met. Soe. 1883, IX. 



t Rainfall at Charrapenyi. Quart. Journ. Met. Soc. 1882, VII. 



X Scott's Meteorology, p. 332. 



§ Stirling. Notes on the Meteorology of the AustraUan Alps. Trans. R. Soc. Victoria 



