44S 



NATURE 



[March 7, 1895 



There are two ways in which the water may be stored ; either 

 by thiowing a dam right across the river and forming a great 

 lake above i', or, if such a place can be found, by diverting the 

 flood water into some suitable hollow, and drawing it off 

 from there at the season of low supply, as done by 

 Herodoiui' celebrated Lake Moiris. At one lime there was 

 a hope that such a storage basin might be found. An 

 American gentleman, named Mr. Cope Whitehouse, in search 

 of the real .Micri^, f.iund a very remarkable saucer-shaped de 

 pression just south of the Fayiim. We knew it coul-t not have 

 been NKeri.s, because in its bed we found no traces of a deposit 

 of Nilotic mud, but it might be possible all the same to utilise 

 it. The place was very carefully surveyed, and the project was 

 estimated ; but it was found that the co-t of conveying the water 

 into this basin would be so great that it was out of the question. 



Attemion was then turned to the possible sites where a stone I 

 dam might be built right across the river. The souihern i 

 bounitary of Egypt just now is near Wady Haifa, the second 

 cataract. It is no use going to look for sites south nf this, for 

 the country is in the hands of the M.ihdi and his fierce dervish 

 soldiers. North of this point, unquestionably the best site, 

 perhaps the only possible site is where the Nile valley is i 

 traversed by a broad dyke of hard Syenite granite, in passing 

 over which the river forms its first cataract just south of Assouan. 

 It is here divided into several channels between rocky islands, 

 and no channel is deep, so that it would be easy to divert the 

 water from one after another, to lay bare the bed of the river, 

 and lay the foundations of the dam in the open air. It wants 

 no engineer to understand what an adv.intage this is. 



And the great dam, Mich as was <le«igned by Mr. Willcocks, 

 would have been a work worthy of the land of the Pyr.imiil-and 

 Karnak — a great wall of squared granite blocks — 82 feet thick at 

 base, of a maximum height of 115 feet, ij miles 1 mg, pierced 

 by sluices large enough to allow of the whole Nile at highest 

 flood rushing through. The lake formed would have been 120 

 miles long. Would this not have been a work of some majesty 

 to commemorate for ever the English rule in Egypt — a work 

 one would have been proud to have had a hand in ? But it was 

 not to be. The Egyptian saw no objection to it. The money 

 could have been found. But there was an insuperable obstacU 

 created when, on the Island of Phil.-e, about 250 D.c, Ptolemy 

 II. built a temple to Isis, on the site of older buildings long 

 disappeared. Round this temple other buildings clustered, 

 built by Greeks and Romans. Those of you who liave not seen 

 them, are probably familiar from pictures with the group of 

 venerable buildings standing amidst palm trees on the rocky 

 island, and reflected in the waters below. 



Had Ptolemy only built his temple on the island of Elephan- 

 tine, a few miles north, it would have been unaffected by the 

 great dam, but Philae is just to the south, or up-stream side 

 of where the great d.im must necessarily have come, and in 

 consequence the island, with its temples, would be drowned for 

 about SIX months every year. Vou probably remember the out- 

 burst of rage and indignation which the announcement of this 

 proposed desecration created in London last summer. It was 

 not to be tolerated that England should commit such 

 vandalism. In vain it was answered that the place belonged 10 

 Egypt, not to Engl.ind— that the Egyptian, who was to gain so 

 much by the dam, cared absolutely nothing aliout Ptolemy and 

 his temples — that he was prepared to pay a large price for a 

 great work to benefit his country. What business was it of 

 England to forbid him ? 



.\nd it w.as not only the English who were indignant. 

 For oiice, and only for once, I fear, since we occupied 

 Egypt in 1882. was educated opinion in England and Kranceat 

 one. Both alike insisted that Philae should not he drowned. 

 Nor must I admit had all the engineers that wereinlereslcd in the 

 question the full courage of their opinions. While they longed 

 to build the dam, and lamented the perverse fate that h.id put 

 Phili- there, still they wished to spare Philae — and their voice 

 has prevailed. The majestic structure has been cut down 27 

 feet, nnd now will only be 88 feet high, and Phil.%- will stand 

 henceforth in a lake, but will never be drowned. 



Personally I accrpt the situation, (or I never believed that it 

 would be sacrificed. But yet as an engineer, I must sigh over the 

 lost oppiri unity for ICngljnd of making such a splendid rcservnir. 

 And «s a friend to Egypi, I nigh still more that thccounliy will 

 not have such a splendid supply of water as wouM enable 

 Upper Egypt to have the full lienefiis now possessed by Lower 

 Kgypli '"id Lower Egypt to expand and flourish. 



NO. 1323. VOL. 51] 



The reduced scheme will, however, be a great boon to the 

 country, nnd I trust will now be put in hand without delay. 



In 1S84, when the expedition up the Nile was first being 

 considered, I was asked by the General Otlicer command- 

 ing in Egypt, whether I thought there was any possibility 

 of the Mahdi diverting the river in the Soudan, and depriving 

 Egypt of its water. The late Sir Samuel lijker was in Cairo 

 at the time, and I consulted him as to whether he knew of any 

 place in the Nile valley where during hiL'hest flood the water 

 spills off to the right or lefi, towards the Red .Sea or the 

 Libyan Desert. He said he was sure there was no such place, 

 and I then told the General it would be impossible for the 

 Mahdi to divert the Nile. I was sure that with his sav.iges he 

 would never dam up the low supply until its surface attained 

 the height of flood supply, and if even then during flood there 

 was no spill channel, Egypt was safe enough. 



But what the Mahdi could not do, a civilised people could do. 

 A Government official has no business to talk politics, and the 

 Royal Institution is no place for politics; but I may be allowed 

 to point out an evident enough fact, that the civilised possessor 

 of the Upper Nile valley holds Egypt in his grasp. 



At this moment the Italians are on the eastern edge of that 

 valley — a nation, I must say, who have been consistently most 

 friendly to us in Egypt. Supposinj^ ihat they occupied 

 Khartoum, the first thing they would naturally and very properly 

 do would be to spread ihc waters of the Low Nile over the 

 Soudan: and no nation in Europe understands irrigation so 

 well. And what then would become of Egypt's cotton crops? 

 They could only be secured by a series of the most costly dams 

 over the river, and the fate of Philae would surely be sealed. 

 But more than this : a civilised nation on the Upper Nile 

 wouM surely build regula'ing sluices across the outlet of the 

 Victoria Nyanza, and control that great sea as Manchester 

 controls Thirlcmere. This would probably be an easy opera- 

 tion. Once done, the Nile supply would be in their hands; 

 and if poor little Egvpt had the bad luck to be at war with 

 this people on the upper waters, they might flood them, or 

 cut off their water supply at ilicir pleasure. 



Is it not evident, then, that the Nile from ihe Victoria Nyanza 

 to the Mediierranem should be under one rule ? That time 

 is perhaps far olT. I conclude what I have to say to- 

 night, by giving you the assurance, and I challenge contra- 

 diciion, that at no time in the long history of Egypt under 

 Pharaoh or Ptolemy, Roman or Arab, or Turk, have the 

 people of the country been so prosperous, or so justly ruled 

 as during the last nine years. 



OBSER VA TIONS OF S UN-SPO T SPEC TRA . ' 



I. The Widening of Iron Lines and of Unknown Lines in 

 Relation to the ^unspot Period. 



TT is now twenty eight years since I discovered that the lines 

 seen in sun-spots were subject to widening,- and that dif- 

 ferent lines were widened at different times. 



It was not, however, till 1S79 that I was enabled to com- 

 mence daily routine work of such a nature that all observations 

 were comparable i«Av se. This desideratum was secured by 

 limiting attention to the twelve lines most widened between K 

 and D. 



In 1886 ' I gave an account of some of the early results ob- 

 tained by this research. I have recently commenced the com- 

 plete discussion of the whole series of observations to the 

 present year. 



This discussion, involving 21,000 lines widened during the 

 period in question, has necessitated three special researches: 

 the first, dealing with the lines with which, contemporaneously, 

 coincidences have been found in ihe laboratory ; ihe .second, 

 dealing with those the origin of which is so far unknown : aiid 

 the third, with the distribution of both sets of lines in spots ii^ 

 relation to the sun-spot period. 



To make the woik as definite .as possible, I am, in the first 

 instance, confining the inquiry concerning the known lines to 

 lines ol iron b.rsed u|)on the examination of the pure electrolytic 

 iron referred to in a previous communication. 



' A Paper read ai llie Royal Society, by J. Norman Lotkycr, C. U., 

 F.R.S. 

 - ■' Roy. Soc. Proc."vol. xv. p. 956, 1866. 

 3 " Roy. S'ic. I'roc." vol. xl.p. 347. 

 * ■' kuy. Soc. Proc." vol. liv. p. 35^. 



