THE PHYSICAL GEOGRAPHY OF AUSTRALIA. 265 



tion in their carrying capacity. Viewed in this light, it seems to me 

 improbable that any system of subterranean channels could always 

 remain effective along comparatively low levels. Against this opinion 

 it may be stated that the flood waters filter through the upper strata 

 and are thus freed from sediment before the lower levels are reached. 

 But this is not by any means conclusive, for the efficiency of filter beds 

 is liable to become impaired or altogether ineffective by heavy deposi- 

 tion of sediment and superincumbent or internal pressure. As previ- 

 ously remarked, the central basin of our continent is characterized by 

 an almost uniformly low depression, in places actually below sea level, 

 over which the flood waters of our inland rivers spread out in immense 

 shallow sheets, but through which it is scarcely possible they can 

 gravitate to the sea in opposition to the local hydrographical conditions. 

 Throughout these central catchment areas an absolute deposition of 

 sediment occurs, and most of the waters rapidly disappear by the simple 

 process of evaporation. On higher levels, where the waters pass over 

 or are collected on highly absorbent cretaceous beds, some are retained, 

 from which our artesian supplies are probably derived ; but even here 

 a very large percentage is lost by evaporation, which, in my opinion, is 

 of itself sufficient to compensate for the speedy drying up of shallow 

 water holes and river beds. 



Along the eastern seaboard there are several natural reservoirs of 

 fresh water, such as Lakes George and Bathurst and other smaller 

 basins, inappropriately called lakes, but which in reality are merely 

 lagoons. These are, however, comparatively shallow; even the largest 

 has been known to be quite dry in times of severe and protracted 

 droughts. The most remarkable and at the same time unique of all 

 the Australian lakes is that which occurs in the alpine regions of 

 Gippsland. Situated in one of the recesses of a lofty range culmi- 

 nating in Mount Wellington, 5,000 feet above sea level, is a beautiful 

 lakelet known by the native name of Tali-karng, whose height above 

 sea level is about 3,000 feet. Mr. A. W . Howitt, who examined it in 

 1890, concluded that the basin of the lakelet has been formed by an 

 accumulation of rock fragments that fills the valley of Kigothoruk 

 Creek, and thus dams up the water, which does not overflow the 

 embankment even in times of flood, it is about 100 feet in depth in 

 the deepest part; the surface is pear-shaped, and it covers an area 

 estimated at about twenty-six acres. 



Climate. — The potent influence of climate upon the inhabitants of a 

 country as well as upon its natural and artificial resources renders its 

 consideration essential in dealing with the subject of physical geogra- 

 phy. Notwithstanding the rapid development of Australian meteor- 

 ology during recent years, resulting chiefly from the widely scattered 

 ramifications of the Queensland weather office, under the enthusiastic 

 direction of Mr. Clement Wragge,the climate of our country as a whole 

 has not yet been satisfactorily elucidated, although the older estab- 



