Discussion. the Isthmus of Suez and the Canals Of

376 ISTIIMUS OF SUEZ.

Mr. GLYNNsaid, that a former Paper on an analogous sub,ject, which he had presentedto the Institution, had induced Prince Lot& Napoleon (€1. M. the Enlperor of the French,) to express, at a Mceting of the Institution of Civil Engineers, his views on the cnnal- isation of Central America, ant1 had elicited much valuable informa- atiou. He hoped the present communication wonld be attended with a similar result, and that, as some Bhnbers of the Institution had lately visited Egypt,they might be induced to lay before the Meeting, the results of their experience, moreespecially as the accuracy of the levels taken by M. Lephre had recently been questioned. Mr. R. STEPIIENSON,M.P., V.P., was most willing to take part in tlie tliscur:;.ion of aqnestion, in wbich all the nations of Europe were so deeplyinterested. In 1847, hecombined with M. Paulin Talabot, a French Engineer, M. de Negrelli, an Austrian Engineer, andLinant Bey, a FrenchEngineer, who hadbeen long in the Egyptian service, in having a survey made of the Isthmus, with the view of testing the accuracy of the levels previously made, and the results of the experience so obtained, were diametrically opposed to the statements made in 1799, by the French Engineers. Mr. Lepere performed his operations with great care, but besides the difficulties under which he labonred, mentioned in the Paper, he was frequently misled, no doubt, by the mirage. Rut before proceeding to give an account of the recent expedition, in which he had been engaged, he

Captain Jaurhs, of the Imperial Marine, and Member of the Council of the Admiralty of France. M. Lentzc, of Berlin, Chief Engineer of the Works on the Vistula. M. Lieussou, Hydrographical Engineer to the Imperial Marine of France, Paris. Mr. J. R. McClean, Member of the Institution of civil Engineersof London. Mr. Charles Manby, Secretary of theInstitution of Civil Engineers of London. M. Montesinos. Director of Public Works of Madrid. M. de Negrelli, of Vienna, Inspector-General of llailways in the Austrian Empire. RI. Pal6ocopa, of Turin,Minister of PuhlicU'orlrs for the Kingdom of Sardinia. M. RGnaud, Inspector-General, and Member of the Council of the Pouts et Ctlal?se6es,Paris. Mr. J. M. Itendt.1, Past President of the Institution of Civil Engineers of London. M. Rigault de Genouilly, Rear-Admiral of the Imperial Marine of France, Paris. President-M. F. W. coNRaD.-Secrefaries-". LIEUSEOUand MANBY. J. G.

' ti'dt Ivhutes of l'Iwccdilrgs Ilist. C. K., 1847, vol. vi., p. 399.

Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. 1STIIYtIS OF SUEZ. 377 would briefly describe the projectwhich had been proposed by Linant Bey, on the assumption, that the levellings of M. Lephre were cor- rect, and that there was a difference of level of 30 feet between the Red Sea. andthe Mediterranean. Linant Bey proposed tocarry a canal from the Red Sea through the Bitter Lakes, to Lake Timsah, and thence through the lagoons of Lake Menzaleh, to Tineh, (Pelu- sium,) on the Mediterranean: he thus expected to creafe a current through the canal, 3of miles, or 4 miles an hour. The project appeared very feasible, and was calculatedto excite high hopesof success. The expedition of 1847 took as a datum,the zero of theNilo- meter at Cairo : thence the levellirtgs were made CO Suez, and were checked byanother set carried along the Indian route; the two series of levels, thus extending over a distance of 230 liilom&tres, or 150 miles, were found to agree within half an inch. Two men were attached to each of the levellers, of whom there were also two, and the latter were allowednot to commuuicate orally with each other: but if there was a difference of even one-twelfth of an inch in their results, the observation was ordered to be repeated. Another set of check-levellers compared notes wit,h the former, at the endof every 3 miles, and in case of any discrepancy, the operation was renewed. From Suez, lines of levels were run to Tineh, but these were not so correctly made, as they exhibited a difference of 10 inches in the finalresult. The importantfact, however, was ascertained,that at low-water, there was no essential difference in the level of the two seas, and that at high-water,was it not more than 4 feet, therise of tide beingabout 1 foot in the Dlediterranean, and about G feet in the Red Sea. Thus it becameevident, that it wouldnot bepracticable to keep open a level cut, or canal, without any current between the two seas, andthe project was abandoned. Theother results obtained from these operations were, that the rise of the Nile at Cairo, was from 17 feet to 28 feet, (the minimum and maximum being equally disastrous for the country); and that the heightof the river at Cairo, was 68 feet 7 inches above the Mediterraneari at high Nile, a fall equal to 53 iuches per mile, with a velocity of 5 feet per second, and at. low Pu’ile, the fall was about 48 feet, or 33 inches per mile, and the velocity was 1 foot 7 inches per second. Great danger hacl been apprehended from any attempt to divert the waters of the Sile at Cairo, towards the Red Sea, on account of the great difference of level, yetthere was sufficient evidence to show ttlat,fornlerly, a portion of the waters ran into the Red Sea. The traces of the old canal were still fresh, owing to there being no rain, and but little wind; the sand had almost entirelydisappeared from thesurface, which now consisted of gravel o111y. The spoil banks on e;tc.li side of the

ancient canals were still visible, and were as high as many of the railway embankments in England. From Suez to the Bitter Lakes, a distance of about 30 miles, the country was covered with sand similar to that on the sea-coast : there would, therefore, be no difficulty in extending the Red Sea to that point, with a bank of sand and gravel on either side, G feet, or 8 feet inheight. TheBitter Lakes, there could be littie doubt, were, formerly, a portion of the Red Sea: the marine shells found at the bottom of thelakes, and those of theRed -Sea, were identical. These shells were also to be seen on the sides of the lakes, and even on a raised beach, which was now above the levelof the Red Sea. A great amount of infiltration was continually taking place from the Red Sea into the Bitter Lakes, but the evaporation was so rapid, that the water never actually appeared at the bottom, which consisted of a bed of salt of considerable thickness: brine of intense saltness was found, throughout the track, at the depth of a few feet. At thenorthern extren~ity of thelakes, there still existed the remains of formercivilisation, and some veryextensive ruins, which, in all probability, were those of a town erected on the spot, at a time wheu it constituted the head of the Red Sea. This town could not have existed without the canal, or similar means of ob- taining fresh water, and the inhabitants, most probably, had located themselves there, at a periodwhen the level of thedistrict was lower than at present, and must have received the means of irrigation from the waters of the Nile, which alone could have imparted to it the proverbial fertility of the Land of Goshen. The destruc- tion of the town was, probably, consequent on the same uphea.ving of the surface,which he conceived had raised the beach of the Bitter Lakes. A collfirmatory proof of the existence of a canal might be deduced from the nan~eof Lake ' Timsah,' which signified a ' cro- codile,' an auimal whichcould only exist in fresh water; and the shells peculiar to the latter, were those alone wl~ichwere to be found in the bed of thelake. Theport of Tineh, on the shore of the Mediterranean, was, atpresent, utterly useless for all mercantile purposes. The result of these lcvellings induced Linant Bey to change his plans, and he had since proposed to conduct the waters of the Kile to above Moukfalr, and to lock down, in both directions, to the Red Sea and to the Mediterranean. He should state, thatM. Paulin Talabot andM. de Negrelli, being unablepersonally to visit Egypt at the period ofthe survey, the former had delegated to N. Bourdaloue the task of performing the Irvelling nllrtded to, whilst the soundings on the coast of tllc Medi-

Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. ISTlIMUS OE’ SUEZ. 379 terranean, opposite Pelusium, bad been intrusted, by &l.de Negrelli, to a staffof assistants sent over for the purpose; Mr. Stephenson undertaking to make a personal investigation of the general features of the country, over which he travelled, partly on foot, starting from Cairo by-the usual track to Suez, thence down the west shore of the Red Sea, a distance of two da,ys’ journey, seeking a port offering greater advantages than Suez ; he then returned north by the Bitter Lakes to Lake Timsah, and thence still further north to the high groundnear Lake Ballah; thence he returned to the Wells of Sababiar; thus he had looked over, but had not actually traversed, the country around Lake &Ienzaleh and towards Tineh, (Pelusium,) onthe shore of the Mediterranean. He then,making deviations fromthe western route,travelled along the Onadee Toumilat to Eulbiesand to the ruins of ancient Bubastis, visitingthe high ground to the north. This investigation had been made during two visits to Egypt, and he had si~nultaneouslyexamined the country with a view to railways, and to the practicability of executing the proposed canal. The barrage of the Bile, which was in course of construction by Mougel Beyl a French Engineer, in the service of the Pacha, was one of those vast undertakings which would do credit to any nation; as n~auyas fifty thousandmen were employedon the works. The barrage might be described as a large perforated dam, with nurner- 011s openings,each 16 feetwide: its ob,ject was to pond up the Nile for a spnce of 30 miles, and then, by meaus of canals, to dis- tributeits waters to the Delta for the purposes of irrigation. Serious doubts had, however, been expressed as to the eventual success of the scheme. &. GaEavEs said,that both the navigation of theRed and that of theMediterranean at the outlet of the proposed canal, presentedgreat difficulties. There W-itsa continualcurrent along theshores of the Mediterranean,carrying eastward lowards the coast of Syria, all the alluvial matter brought down by the Kile, ;lud teuding to fill up the proposed harbour at Tineh. Ile thought, that the usual rise and fa11 of the Red Sea was estimated at about 3 feet, but that at certain seasons of the year, the mean level was raised 2 feet by the continued action of the wind in one direction. I-Ie was of opinion, thatthe canal would notanswer the require- tnents of British commerce, and that the coustruction of a railroad was, in mat~yrespects, a rnuch more feasible project. Mr F. En.,\rTmvnrm renlnrketl, that, part of the land was slated to be 30 feet lower than the level of the sea. Now if it were com- lwwd c:f‘ w:d done, or of gravel don^, the u-atcr ~vouldpercolate

Downloaded by [] on [11/09/16]. Copyright © ICE Publishing, all rights reserved. 380 ISTHMUS OF SUEZ. throughthe strata, but if the sand and gravel werecombined together, the result rvoultl form a concrete. Mr. AYRTONobserved, that the ancient authors did not specify the period at which the Bitter Lakes were connected with the Red Sea. He wished to know, whetherthe ridge which now divided them, at El Guisr, was, geologically,thc former natural bed, or whether it was the result of later accumulations of sand. Both of these positions had been assumed as B basis of argument. Mr, R. STEPHENSON,MP., V.P., said, that the ridge now exist- ing between the end of the Red Sea and the Bitter Lakes consisted of tertiary strata, thefossils of which were identical withthose of the London basin, and of the Hill of Montmartre near Paris: Egypt, England, ad France were, consequently, of thc same age. The character of the district to the north of the lakes did not, appear to be exactly the same: in that district there were hills of limestone which had been used for building purposes in the walls of ancient Serapiurn.

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BIay 27, 185 1. ANNUAL CONVERSAZIONE. The Session terminated with a Conversazione given by the l’re- sident to the Members aud a large number of visitors; on which occasion, an interesting collection of Models of E~~girweringCOII- structionsand specimens of Works of Art, was exhibitecl inthe rooms’of the Institution.