RINGBARKING AND ITS EFFECTS. 101 
growing trees and evaporated from their leaves is allowed to find 
its way to the creeks and rivers. The fact that the Eucalyptus is 
— the most vigorous growing tree known, and that it has 
to a possible explanation of the anomaly presented by most of our 
Australian rivers. If we compare such a river as the Thames in 
ge with the Hunter in New South Wales, we shall find that, 
ough the area of drainage is not very unequal, the Hunter having 
. er area and the heavier rainfall, the outflow of the Thames 
ad 
not seen any record of the annual outflow of the Thames, and none 
has been kept of that of the Hunter, but I take the fact that ae 
es is navigable for a great part of its course, even to a hei 
of 250 feet above sea-level, and the Hunter scarcely at all, as 
proof that the former must have very much the larger quantity of 
\ water. There must be a reason for this, and though an under- 
‘o our rainfall is, as I suppose, peculiar to Australia, then in look- 
| ard the cause sweat find one that is also peculiar to Aus- 
; y 
“upposing that the evaporation here is greater than in other 
countries situated in the same latitude either north or south of the 
Our forest growth is certainly exceptional, whether the two 
re connected in the way of cause and effect or not. I do 
not know that we have sufficient data to determine the question 
