April 12, 1906] 



NA TURE 



563 



Several other monuments, e.g., Chun Castle and 

 Cromlech, are to be found in the immediate neigh- 

 bourhood of the Tregeseal Circle and the Longstone, 



but these will have to await further investigation as to 

 their character and antiquity before any conclusions 

 concerning their astronomical use can be deduced. 

 Norman Lockyer. 



IRRIGATION IN THE TRANSVAAL. 1 



THERE are few subjects on which such a great 

 diversity of opinion exists as on the adminis- 

 tration of South Africa. Free labour and Chinese 

 labour, the electoral franchise of the Transvaal, the 

 various routes from the interior to the coast, the 

 language to be adopted in Government schools — on 

 these and on many other points one hears well-in- 

 formed and perfectly honest-minded people assert- 

 ing", and that with considerable warmth, the most 

 opposite views; views which they maintain are 

 founded on facts. 



But there is one subject on which it may be asserted 

 all are agreed, and that is that the great want of 

 South Africa is not gold or diamonds, but water in 

 sufficient volume to be spread over the land when 

 and where it is required. Not that the country is 

 generally devoid of rain, but, as it has been well put, 

 " When rain is wanted it is generally not there; when 

 il is not wanted it is invariably present." 



No one was more fully alive to this want than 

 the late distinguished High Commissioner, Lord 

 Milner. He borrowed the services of Sir William 

 Willcocks, one of the most prominent members of 

 the small band of English hydraulic engineers from 

 India who have done so much on the Nile. He 

 further procured two engineers, Messrs. Gordon and 

 Strange, thoroughly trained in the excellent irrigation 

 school of India, to advise, one in the Cape Colony and 

 the other in the Transvaal, upon irrigation matters. 

 Willcocks 's tour took place during the war, when he 

 was much hampered by the difficulty of getting about 

 the country. His visit, also, was a short one, but not 

 too short to prevent his submitting a very able report 

 full of thoughtful suggestions. Gordon and Strange 

 went to South Africa after the war. They are there 

 still, and may render invaluable services to the country 

 if the agricultural classes can be made to believe that 

 they have anything to learn, and that there may be 

 advantages in accepting a scheme which requires all 



1 " Inter-Colonial Irrigation Commission." It 

 + 166. (Pretoria : Government Printing and St; 

 7 s. 6if. 



NO. 1902, VOL J!)) 



im Report. Pp xxx\ 

 nery Office, 1905.) Prit 



to submit to certain restrictions for the benefit of all, 

 instead of each farmer being free to follow his own 

 devices. A distinguished member of the present 

 ( a l>i net has remarked that the Boer farmer 

 seems to have a perfect instinct for disobey- 

 ing the law. Unless he learns to substitute 

 for this instinct the dictates of reason, there 

 is little hope of irrigation flourishing in 

 South Africa. 



Besides procuring the services of these 

 officers, Lord Milner shortly before leaving 

 South Africa appointed a commission to re- 

 port on the legislation required to enable the 

 water resources of the Transvaal and Orange 

 River Colony to be thoroughly utilised, and 

 also on " the precautions necessary in deal- 

 ing with subterranean water, more especially 

 in areas situated on the dolomite formation, 

 so as to prevent as far as possible the diver- 

 sion of such water from public stream-- and 

 fountains to the detriment of the public." 



It was directed that an interim report 

 should be submitted as soon as possible on 

 this last subject. This report, dated May 20, 

 1905, is now before us. The commission con- 

 sisted of Mr. Justice Wessels, Judge of the 

 Supreme Court of the Transvaal, three other Dutch 

 and two English gentlemen, one of whom was Mr. 

 Strange. 



The commission has collected a large mass oi 

 interesting information and opinions from thirty-one 

 witnesses, of whom no fewer than nine were pro- 

 fessional geologists. South Africa is to be congratu- 

 lated in possessing so many scientific gentlemen whose 

 evidence was of great value. The other witnesses 

 were principally engineers and farmers. Of the latter 

 there were seven. 



In framing an irrigation project the two first ques- 

 tions to ask are generally, How much land is it pro- 

 posed to irrigate? How much water is available to 

 irrigate it? In all but the most favoured countries 

 the area which it is desired to water far exceeds the 

 volume of water available. In the Transvaal the 

 irrigable area can easily be marked out. It is not 

 so easy to say how much water is at our disposal. 



Usually irrigation is practised by canals and water- 

 courses drawn from rivers and lakes, natural or 

 artificial. By careful observation one finds how 

 much water, at the season when irrigation is required, 

 can be drawn from the river or lake. Elsewhere 

 irrigation is practised by pumping water from wells, 

 going down to the water-bearing stratum. Such a 

 stratum is usually found in alluvial plains at no very 

 great depth, and wells may be sunk within a few 

 hundred yards of each other without causing injury 

 by one exhausting the other. The recent Indian 

 Irrigation Commission found that in that country 

 about 13 millions of acres were yearly watered in this 

 way. 



The peculiarity of the situation on the dolomite 

 formation of the Transvaal is that the subterranean 

 water tapped by the boring rod is not due to the rain 

 which falls vertically on the surface of the land above, 

 but that the whole of the limestone substratum is 

 pierced by holes and tunnels, flowing streams, and 

 stagnant reservoirs, so that if water be pumped from 

 a well there is no certainty that another well situated 

 ten miles off may not be thereby sucked dry. 



Ultimatelv the water finds its way out to the surface 

 through springs discharging at times more than 

 50 cubic feet per second. It seems evident that the 

 catchment basins of these subterranean waters do not 

 necessarily correspond with those of the earth's surface 

 above, and the problem of defining their limits and 



