modern rivers flow, with but a slight fall to the sea by way of the Murray River Valley.
During the past thirty years the Victorian Department of Mines has carried out an immense amount of boring with the diamond drill, by which the underground contours of the valleys, and also the trend of the deep leads extending north and south from Ballarat have been ascertained.
It seemed to me that a comparison of the data thus obtained might prove of interest, and for this purpose I have selected the statistics of bores put down furthest north on three main leads, where the hilly country subsides into the great levels of the plains through which the River Murray winds its course towards South Australia and the sea.
Each locality chosen is not far distant from the termination of the flow of basalt, by which the old valley had been levelled, and which itself is, at its termination, levelled off by the later alluviums of the plains.
The following are the data from which I have drawn certain conclusions:—
|No. 9 Bore at Bung Bong.|
|Height of surface above sea-level||714 feet|
|Depth of Deep Lead channel below the surface||300 „|
|Distance from the bore to Swan Hill on the River Murray, by way of Bet Bet Creek and the Loddon River||200 miles|
|'No. 8 Bore at Charlotte Plains.|
|Height of surface above sea-level||708 feet|
|Depth of Deep Lead channel below the surface||270 „|
|Distance from the bore to Swan Hill by way of Tallaroop Creek and the Loddon River||180 miles|
|No. 5 Bore of Second Line near Baringhup.|
|Height of surface above sea-level||600 feet|
|Depth of Deep Lead channel below the surface||226 „|
|Distance from Swan Hill by way of the Loddon River||191 miles|
- In each case, in order to approximate the conditions of the "lead" with those of the River Murray, I have deducted from the results of boring the depth of "wash," and have also allowed 5 feet for the possible depth of water.
- On the authority of Mr. A. Everett, chief draughtsman, Department of Mines and Water Supply, Victoria.
- I am indebted to Mr. Jas. Travis, Secretary for Mines in Victoria, for this information.