143 
Our Lakes and their Uses. 
By Frepx. B. Grpps, C.E. 
[Read before the Royal Society of N.S.W., 1 September, 1886.] 
THE influence of lakes in all parts of the globe on the river systems 
in which they are included or with which they are nearly connected, 
and through their channels, on the wealth and commerce of diff. 
erent nations, can only be justly appreciated by an intimate 
knowledge of their physical features and geographical position, 
but their value in stimulating commerce and different industries 
is of such world wide recognized importance, that the investigation 
of the lake system of this Colony should commend itself to more 
than ordinary interest. But for the Nyanza lakes, more than 3,000 
been unknown. But for those huge ties bbe instead of the 
mighty cities which covered its valley with a dense population, 
which were the centres of the arts and sciences, the very cradles 
indeed of civilization, there would have been for all ages a silent 
desolate wilderness, as dreaded by the traveller as the Great Arabian 
D nclouded sun would have blazed day after day on arid 
sands on a treeless waste, over which the scorching winds would have 
blown as a furnace blast. Human life in that dreary domain 
would have been insupportable ; but it was otherwise ordained. 
Chiefly through the instrumentality of the Nyanza lakes, the valley 
of the Nile was ordained from remote ages and through countless 
generations to hold pre-eminence for its great fertility. Year after 
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pour torrents of water into these lakes and increase their depth. 
This increment is gradually distributed through the channel of the 
White Nile, keeping up a constant stream, m, whilst its ts tributaries, the 
Atbara and Blue Nile from the Abyssinian highlands, so swell its 
volume with their muddy streams when in flood, that it gradually 
sar the lower valley. Thus in this rainless region the seed is 
nated and nourishment is given to the crops, whilst the yearly 
senoatt of silt accounts for the pg pcan fertility of the soil. 
Just as the Nyanza lakes serve as the cisterns of the Nile, so the 
Ttalian lakes act as balance reservoirs ty i Be Adda, Oglio, 
