CORRESPONDENCE

Evening Post, Volume CIX, Issue 115, 19 May 1925, Page 7

CORRESPONDENCE

MUSCLE SHOALS AND BOWEN RIVER

TO THE EDITOR

Sir,—Enormous works are being carried out at Muscle Shoals on the Tennessee River in America for the purpose of producing hydro-electric power for the extraction of nitrogen from the air, and other industrial pursuits. The river falls 100 feet in 40 miles, and with a view to cresting artificial falls, it has' bt-en arranged to erect threo enormous dims. One of these, the Milson Dam, has been under construction. for years. Next lo the Panama Canal., this is the biggest engineering work ever undertaken by the United States. The dam is nearly one mile in length. Its height l.inges from 95 to 134 feet, and it covers 20 acres of space. When completed it will contain 36,500,000 cubic feet of masonry. It will back up the Tennessee River for 18 miles, forming an artificial lake with an average width of three-quarters of a mile. Apart from the water-wheels, piping, dynamos, etc., the cost of the dam alone will be 51,000,----000 dollars., or approximately £10.000,----000. This enormous expenditure is being incurred to obtain a continuous power of only 200,000 horse-power. The cost of the dam represents £50' per horsepower installed.

_ The Bowen River falls 1200 feet in a little over a mile. It is estimated that the necessary dam for deflecting the water will not cost more than £500. As it is proposed to install 20,CC0 horsepower, this only represents 6d per horsepower, instead of £50 at Muscle Shoals. As the pressure of water at the Bowen power will be over twenty times that of the Muscle Shoals, less than one-twen-tieth the amount of water will be consumed yer horse-power developed. Therefore, sil the water-wheels and piping will be nsrvsyondingly smaller, and even the dynamos, du e to the higher velocity, need not be so large per unit generated. Consequently, apart from the dam. the other items of expenditure at the Bowen, including a small tunnel, will be infinitely less than that at the giant American installation.

In spite ot the above facts, there aro a number of Little New Zealaiulers (some influenced by Chile nitrates interests), who only view the proposition through the spectacles of the ultra sentimentalists, who preach that this waterfall, which 99 per cent, of New Zealand's population will never see, under existing conditions, should not be interfered with, but held inviolate for the gratification of a few aesthetic souls to feast their eyes upon once in their lives, for tho matter of an hour or two. After all, the proposal is not to deflect all the water all the time from the falls. It will only be during the winter months when the glaciers cease to melt that the whole or.'the bulk of tho water will be deflected. . The summer level of the river is much higher than the winter level, due to the melting of the glaciers, combined with the frequent summer rains. It would not pay any company to hai'ness above the minimum flow, otherwise their machinery would be frequently tied up, with the resultant disorganisation and loss. There is not the slightest danger of anyone ever thinking of "harnessing all the summer flow. Consequently, the summer tourists will still be able to feast their eyes on the Bowen Falls. I have never yet found a tourist who expressly visited the sound with the sole object of viewing the Bowen Falls. Theyjire unmistakably beautiful, and I claim to have, been the means of bringing them'a'hundredfold more prominently before the public of New Zealand than the Tourist Department has ever done.— I arDj ate..

J. OBCHISTON, M.I.E.E 10th May.