SCENE ON LOGAN RIVER, SOUTH QUEENSLAND
EFFECT OF GOOD SEASONS.
In closing, the Hydraulic Engineer reports that the succession of good seasons experienced (years 1890-93), and the abundance of water and grass resulting, has occasioned much inattention to water conservation, and he also expresses regret that financial exigencies have compelled the dispensing with some valued members of his staff. The article is illustrated by diagrams, and the studious reader will peruse it with profit.
THE SOURCE OF ARTESIAN WATER.
In his report for 1st November, 1894, the Hydraulic Engineer recurs to the source of artesian water. He regrets that very little can be added to the previous assumption that it lies in the outcrops of the porous beds of the Lower Cretaceous formation on the western slope of the coast range; and he urges the necessity of accumulating facts relating to the bores already sunk, and complains that some owners neglect to give the department the information sought. He urges that legislation should make the furnishing of statistical matter of this kind compulsory. He doubts whether, in the absence of information as to the precise geological conditions subsisting beneath the surface, a map of Queensland can ever be prepared showing with certainty where artesian water can be found; but much may be done by accumulating accurate information with respect to the sinking of bores, nature of strata passed through, amount and pressure of flow, temperature of water, and depth beneath the surface whence obtained in each case. The map issued by the Geological Department would show the water-bearing areas, which means the formation in which water may be expected to be found; but bores can only be put down with reasonable certainty when the entire western country has been prospected.
THE LIFE OF ARTESIAN WELLS.
The life of an artesian well with a permanent spring, says the report, is limited by the durability of the casing. The corrosive action of some water is much greater than others; but there should be no difficulty in renewing the casing when necessary. It has often been discovered that an interruption of the flow, or its serious diminution, is the result of worn-out casing. So much is this the case that there is still controversy as to whether there is any general diminution in the supply consequent upon continuous waste.
ARTESIAN WATER POWER.
The report then discusses the question of using artesian water for power in the industries. The Hydraulic Engineer points out that of the total horse-power used in the United States at that time about 39·5 per cent. was hydrodynamic. Artesian water, he says, can be applied to driving all kinds of machinery, "from a sewing machine or a cream separator to a saw or flour mill; and for fire-extinguishing it is most excellent." He therefore recommends the employment in Western Queensland of turbines and Pelton wheel motors for sheep-shearing, electric lighting, and other kinds of machinery used there, pointing out that the horse-power available was—At Blackall, 8·04; at Cunnamulla, 41·53; at Charleville, 123·41; and at Thargomindah, 63·51.[a] He further recommends the utilisation of the artesian supply for street mains, a suggestion since carried out with great public advantage in several western towns. While Mr. Henderson doubts the utility of artesian water for irrigation, he says that, generally speaking, it is quite as valuable as that from town mains, rivers, and falls for developing power. The aggregate area to date in which precious artesian water has been found in Queensland is 117,000 square miles, and he feels that this area would be rapidly enlarged by exploration by both Government and private borings. The shallowest completed flowing well in Queensland at that date was 60 ft., and the deepest 3,630 ft.; the average depth so far as known to the department was 1,289 ft.