184 NEW SOUTH WALES. 



hundred feet in height. The Canobolus Mountains, further to the 

 westward, are four thousand four hundred and sixty-one feet high, 

 and of primitive rock; beyond these the extensive plains of the 

 interior, the valley of Millewa or Murray River, seem again to be 

 entirely composed of sedimentary rocks, similar to the sandstone of 

 the coast. 



The climate of Australia may be considered generally as very dry ; 

 the irregularity of the rains, and the nature of the soil, all prove that 

 it is so ; yet the aridity is not marked, as in other countries, by a 

 general tendency in the plants to produce thorns, although the 

 peculiarity of the vegetation makes the dryness apparent in other 

 ways. From all accounts, New South Wales is subject to as great 

 atmospheric vicissitudes, as the middle United States. For a series 

 of years, droughts will occur, which in turn give place to years of 

 successive floods, and these prevail to an extent that can hardly be 

 credited, were it not that the account has been received from good 

 authority. As a striking instance of it, Oxley, in his exploring 

 journeys into the interior, in 1817, found the country every where 

 overflowed, so as to prevent him from proceeding; while Mitchell, 

 in 1835, in the same districts, was continually in danger of perish- 

 ing from thirst. The latter states that he found unios (or fresh- 

 water mussels) sticking in the banks of rivers and ponds above 

 the level of the water ; and also dead trees and saplings in similar 

 situations. 



This alternate change must exert a great influence on the produc- 

 tions of the soil ; the rivers ceasing to flow, and their beds becoming 

 as it were dry, with the exception of the pools heretofore spoken of, 

 must likewise have an influence. The prevailing westerly winds 

 sweep with force over the whole country, blighting all they touch. 

 The effect of these hot winds is remarkable, for they will in a few 

 hours entirely destroy the crops, by extracting aU the moisture from 

 the grain, even after it is formed, and almost ready for harvest; and 

 the only portion that is left is that which has been sheltered by trees, 

 hedges, or fences. They thus destroy the prospect of the husband- 

 man when his crops are ready for the sickle. It is thought, and I 

 should imagine with reason, that were the Blue Mountains a more 

 lofty range, this would not be the case, as they would have a tendency 

 to continue the supplies to the streams throughout the year, by the 

 condensation of the vapour from the sea. 



