The Clntha and the Nile.

Otago Witness, Issue 2734, 8 August 1906, Page 14

The Clntha and the Nile.

TO THE 2DITOB. Sib, — In his notes of the 14th inst. your correspondent " Civis " refers to the oftrepeatcd statement that the Olutha discharged more water than the Nile, a statement which I must confess I n.ever could troat seriously.^ The idea that our little stream in its 'course of 150 miles could gather as much water as the great Nile in its course of 40CO miles, draining an area about 20 times as large as the wholo South Island, seemed to me too utterly preposterous! Howe\er, as I have since heard tti-o statement^ maintained in all seriousness, I have looked up statistics on tho point, The Glutha, according to fhe Encyclopaedia Brittanica (ninth edition), has been computed to discharge 1,088,736 cubic feet of water per minute. In a later work it is stated that Balfour calculated the discharge at 1,690,000 cubic feet. Under the article " Egypt " in Encyclopaedia Brittanica I find the following: — " The volume of water " which the Nile pours into the Mediterranean in 24 hours is as follows, according to M, Linaut: — During the low Nile, 150,566,392,368 cubio metres ; during the high Nile, 705,514,667,440 cubio metres. Taking the cubic metre as equivalent to 35.4 cubic feet, the above figures -roughly work out at per minute. — Low Nile, say, 3,700,000,000 oubio feet; hig4i Nile, say, 17,600,000,000 cubic feet. The latter quantity is so enormous, Deing roughly a stretch of water 1000 yards wido, 100 ft deep, and over 10 miles long that one feels inclined to doubt the accuracy of the calculation. Yet if it were incorrect sureiy it would have been referred to and corrected in tho Tenth Edition, which is not the case.

There is, however, curious dispar'ty In tho above figures and the figures given in the same work under tho article "Nile," whiA opens with this sentence: — "This mighty river, which after a course of 3370 miles pours into tho Mediterranean a .low-water current of 61 500cut>io feet per second," etc. This works out at 3,690,000 cubic feet per minute for low Nile, and, taking M. Linaut's proportion as correct, at r iher morja than 17,000,000 cubic feet per minute for high Nile.

It will be seen that even the Jatter very modest figures show the Nile to have an average discharge of water more than six times as great as Balfour's calculation of the Clutha's discharge.

Looking at these figures again, I am inclined to think that the last three ciphers in M. Linaut's calculation .must be intended for decimals, although they are not shown as such. • The current of the Nile is so 6low near the mouth (two miles per hour" at low water and three miles at high water) that it could not possibly discharge such a huge o-uantity of water, — I am, etc. Dunedin, July 21, 1906. O. B.

P.S. — It should be borne In mind that in. the last 1000 mi'es of ite course the Nile receives no tributaries, and flowing through a dry, hot country loses a tremendous quantity of water by evaporation. It would be interesting to know how much more water the Nile carries tt Berber tha» at Cairo.— 0. B,