442 TRANSACTIONS OF SECTION E. 
along the southern portion of the Commonwealth is clearly marked by the 
elevations indicating the good rains received over the south-west corner of 
Australia, and, further eastward, how the ranges east of Adelaide cause good 
rainfall there and prevent the rain from that direction reaching the inland 
parts of Victoria. 
In Tasmania also is seen the effect of the frequency of the moist westerly 
winds, causing high rainfall along the mountain ranges of the west coast, with 
resulting comparative dryness in the eastern parts of that State. 
It may be of interest to note in closing that there exists apparently an 
oscillatory movement of the seasonal rains throughout Australia about a centre 
in the vicinity of Forbes, in New South Wales. It is perhaps a natural 
coincidence that this apparent centre of oscillation is approximately the centre 
of gravity of the Commonwealth’s population, and is not far from the Federal 
capital site. 
This peculiar oscillatory character of the monthly march of rainfall suggested 
the construction of a ‘ Rain Clock.’ In the centre of a piece of cardboard a map 
of Australia is cut out with a die. At the back of this another piece of card- 
board, indicating the rain area, is manipulated on a swivel. By moving the 
second piece of cardboard backwards and forwards with an amplitude of oscilla- 
tion of one-fifth of a circle, the land area of the continent affected by dry or 
wet conditions at any time of the year is approximately indicated. 
The immediate lessons to be learned from a study of the ‘ Clock’ are that the 
seasonal rains are more regular than was generally believed, and that the 
alternating dry and wet seasons are definitely defined. That being so, when in 
obedience to physical law there is an absence of rain during the normally dry 
period in any part of Australia, such dryness should not be regarded as 
drought, and an evil, but rather as Nature’s wise provision for resting the soil. 
2. The ‘ Mallee’ Country of North-Western Victoria. 
By A. 8. Kenyon, C.E. 
The term ‘ Mallee,’ applied to the scrubby forms of Eucalypt characteristic 
of the area to be described, is of aboriginal origin. 
The Mallee country embraces over 11,000,000 acres and includes the greater 
part of the north-western portion of the State, over one-fifth of its total area. 
lt is sharply differentiated from other districts by its soils, plants, and general 
surface configuration. 
Surface Formation.—The prevailing feature is the regular occurrence of sand- 
vidges—of no great height, generally less than 30 feet. They are more or less 
parallel, running from W.S.W. to E.N.E. With an increase in their height, the 
scil becomes noticeably poorer; at times they are over 100 feet above the sur- 
rounding surface, when the parallelism is almost completely masked and they 
form a jumble of sand-hills, locally known as ‘ desert.’ More or less extensive 
expanses of level land with low irregular undulating rises are termed ‘ broken ’ 
country. 
Soil. —The soil varies from rich red clayey loams in the ‘ broken’ country 
to pure white sand in the ‘sandhills,’ and, except in the latter class, is all 
suitable for agriculture. Limestone nodules occur almost everywhere, in places 
becoming almost massive; outcrops of tertiary agglomerated ferruginous sand- 
. stone are plentiful. Salt lakes, generally in the vicinity of the more extensive 
limestone beds, accompanied with ‘copi’ or gypsum earth deposits, are 
numerous. These have rarely any inflow of water, and their saltness in every 
case may be put down to upward filtration. Swamps and terminal lakes without 
any outflow are, however, generally fresh. The ‘ broken’ country occupies 
about 20 per cent., the sand-ridges cover 50 per cent., while the sand-hills 
account for less than 30 per cent. 
Plants.—The sand-ridge country is densely covered with H. Dumosa and 
its varieties. Broom-bush (Beckea) marks the transition stage into sand-hills 
with their desert types of Casuarina, Callitris, Grevillia, Hakea, Melaleuca, and 
Epacris. The ‘broken’ country has large mallee, big pines (Callitris robusta), 
buloke, and belar (Casuarina luehmanni and lepidophloia), sandalwood (M/yo- 
