SCIENCE AND INDUSTRY. 
the choicest ‘sites occupied (though not necessarily half of those avail- 
able), only about one part in a thousand of the lands needing irrigation 
has been benefited. 
One other aspect of the topography merits some attention. All our 
important highlands are collected along the eastern and south-eastern 
coasts. They are probably largely due to wrinkles in the earth’s crust, 
formed by pressure directed against the Western: Australian massif. 
(We see certain drowned “wrinkles” of similar origin in the festoons 
of islands—Solomons, New Hebrides, Tonga, New Zealand, &e.—which 
border our eastern seas.) 
Hence our main mountain valleys are usually disposed along a 
north-south axis, and they obviously lie in just the wrong direction for 
facilitating access to the east coast. The rivers have a tendency to flow 
in meridional lines, as in the Snowy, upper Murrumbidgee, Tumut, 
upper Lachlan, Shoalhaven, Nepean, upper Clarence, Dawson, Burdekin, 
&e., and this disposition of the “grain” of the country has necessitated 
very difficult railway grades just in the most populous part of our 
country. or years it absolutely prevented the construction of coastal 
railways, which are only now creeping slowly from port to port. 
From the Darling Downs, in Queensland, to Kilmore, in Victoria, 
there is only one natural gap in the highlands below 2,000 feet (at 
Cassilis, behind Neweastle). This is a distance of 800 miles, and it is 
extraordinary that no railway has yet taken advantage of this low grade, 
eee. leads directly from our chief coalfield to the interior. (See 
Fig. B.) 
__ Per contra, the coral polyp has taken advantage of the warping 
shore line of Queensland, and has built up a battlement of coral reefs 
for 1,000 miles in the same north and south direction. ‘This insures one 
of the calmest sea routes in the world, though possibly the sea-captaius 
could dispense with the placid seas if they were free from the dan- 
gerous and ever-growing reefs! 
Let us now glance briefly at the climatic controls which affeet the 
development of Australia. We are concerned primarily with tempera- 
ture and rainfall, but we shall find that the humidity is of great import- 
unce in connexion with tropical settlement. 
Since the southern hemisphere consists so largely of water, it is 
natural that on the whole it should haye a cooler temperature than the 
northern. But where large masses of land are involved this difference 
practically vanishes. Tropical seas have a temperature of 80 degrees I’. 
fairly generally, and the effect of a large ocean does not extend indefi- 
nitely inland. If we consider-actual temperature records we find that 
four regions in the world exceed an annual average temperature of 
84 degrees F. These are around Timbuktu, Massowah (on the Red 
Sea), Tinnevelli (at the southern tip of India), and Wyndham, in 
north-west Australia. The two former are arid. The two latter are 
very wet in the hot months. Hence Wyndham (with 84.6 degrees F:) 
‘is undoubtedly one of the least favoured regions in the world go far as 
temperature is concerned. 
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