115 
proceeding from infiltration through the wooded soil, long after the other, contiguous to the open ground, 
has performed its office of drainage and become dry. The ditch on the left will have discharged in a few 
hours a quantity of water which the ditch oh the right requires several days to receive and carry down 
to the valley, and, but for this drainage into the ditch, the water might have remained there for an 
indefinitely longer time. 
Speaking of the forest floor, irrespective of a leaf-mulch surface, Professor 
Harrington quotes Fesca to the effect that the downward movement proceeds 
quickest in a dry dust, only slowly in clay soils, the same amount of water being 
drained through the former in one hour which took two days to drain through the 
latter, and emphasises the point that the service conditions of the soil of a watershed 
are the only controllable factors in the problem. 
The necessity of preserving the dead leaves to form humus should be strongly 
insisted on. It has been proved by Grandeau and Henry, two of the Nancy 
professors, that besides serving as food for earth-worms and other organisms, the 
activity of which keeps the soil porous, friable, and superficially rich in nutritive 
mineral matter, dead leaves fix atmospheric nitrogen to the extent of 12-20 Ib. per 
acre annually. To deprive a forest of its dead leaves is like robbing a farm of its 
dung. 
It may be argued that evaporation from open ground is much more intense than from soil cqyered 
by forests. No doubt this is the case, and Ebermayer, in his " Die Physikalishen Eiiiwirkungen des 
Waldes auf Luft und Boden," gives the following data : 
The forest alone, without the cover of dead leaves, diminishes the evaporation by 62 per cent., as 
compared with that in the open. Evaporation is, consequently, 2'6 times less in the forests, A covering 
of dead leaves and vegetable mould diminishes evaporation by a further 22 per cent. 
Forests with an undisturbed covering of dead leaves and vegetable mould lessen the evaporation as 
compared with that in the open by 84 per cent. 
These data are based on observations made in Bavaria during the summer months. In the Indian 
climate the difference, which increases in proportion to the heat and dryness of the atmosphere, would 
be even more considerable.* 
I now submit the whole subject for consideration of my readers. The 
matter of forest meteorology, and the questions that crop out of it, present many 
puzzling problems to us in Australia, and some of them have as yet baffled the 
meteorologists of long-settled countries. A proper understanding of the principles 
which underlie the relations of forests and moisture is of interest to us in two special 
ways : first, as regards the water supply of a large city (Sydney) ; and, secondly, 
as regards the distribution and conservation of moisture over the whole of the State. 
~ 
Reasonable expenditure for research would be justifiable, if we could be thereby 
placed in a position to deal less empirically with the rainfall we receive, and to know 
how to conserve it more wisely than we do at present. A certain amount of rain 
falls upon New South Wales. Do we take care that it will do us most good, and 
remain with us, benefiting us as long as possible ? Many public questions that loom 
large in the public eye should really claim less of our attention than this. 
i 
* Eibbentrop, op, cit., page 43, 
