Autobiography of Sir John Rennie, F.R.S., Past President of the Institute of Civil Engineers / Comprising the history of his professional life, together with reminiscences dating from the commencement of the century to the present time.

by Sir John Rennie

On my way up a sad accident deprived me of the services of my faithful attendant—I may say friend—Demetrius. We met a boat, having on board the O’Conor Don, Captain Groding, and another, coming down. They hailed us, and as they were short of provisions, I gave them a liberal supply, and invited them to dinner, the two crews regaling themselves and firing feux de joie at the same time. Suddenly a tremendous explosion, followed by a loud cry, was heard, and hastening on deck I found poor Demetrius covered with blood from two deep wounds in the throat and breast, his pistol having burst in his hand. At first I thought it would have been fatal, the effusion of blood was so great. I succeeded, however, in tying up the wounds and stopping the hemorrhage. It was then a question what should be done with him, as I was not surgeon enough to cure him, and no advice was to be had. In this emergency my new friends were so kind as to offer to take him to Cairo, where he could be properly attended to. I gladly accepted the offer, and supplied him with a sufficient sum of money, and requested them to place him in charge of the Consul, with directions to procure the best medical advice, for which I was of course responsible. Independently of the accident, I was much grieved to part with him, and was at first greatly at a loss for his services; but my janissary, an Italian turned Mussulman, and who spoke Arabic very well, and was not a bad cook, cheerfully consented to do what he could; and the reis also, a very civil fellow, as well as his crew, did all in their power to compensate me for the loss of Demetrius, so that after a short time we managed between us to get along pretty well.

I will only add one more incident, because it seems to show that the serpents used by serpent-charmers are not always deprived of their fangs, as is usually supposed, but that there is some real secret which renders them harmless or powerless. I was measuring the Temple of Edfou, when I saw a peculiarly venomous serpent come out of its hole, whilst an Arab boy who stood by fixed his eye steadily upon it the moment he saw it, the reptile fixing his eyes on the boy. The lad began waving his hands gently up and down, humming a peculiar tune in a low, monotonous tone. The serpent seemed to be charmed, and lay perfectly still, listening to and keeping its eyes attentively on the boy, who, finding that he had charmed it, was about to secure it; but at this I was so horrified, that I took up a large stone and killed the reptile. The boy was very angry, and assailed me with the most vehement gestures and imprecations, at which I laughed heartily. I afterwards learned that he was the son of a serpent-charmer, and was collecting these reptiles for his father.

In proceeding along the banks of the Nile, I observed that the land inclined from the margin of the river to the base of the adjacent hills. This is nothing more than might have been expected, as it is usual under all similar circumstances, and is caused by the periodical inundation. Thus, whenever the river rises above the margin, the current naturally diminishes in velocity as it encroaches on the banks, and to a certain extent becomes stagnant, and then deposits the alluvial matter with which the waters are charged; and as the water spreads farther on both sides from the main body of the river, it becomes clearer, and contains less alluvial matter. This is a wise provision of nature, for it enables the waters to extend a long way, and thus to irrigate a great extent of land. In order to ensure this irrigation more effectually, it is only necessary to keep open sufficient channels, which may be done with facility. But suppose this was not the case; suppose the land farthest off silted up first, then it would be necessary, for the purpose of irrigation, to raise the water by artificial means at considerable extra cost, to irrigate those lands farthest from the river. However, in process of time, as the land rises both at the sides of the river and the parts more remote from it where they have attained the utmost level of the floods, recourse must be had to art to irrigate the lands, otherwise their fertility and cultivation must cease, as the quantity of rainfall in the lower valley of the Nile, as it passes through Egypt, is comparatively trifling; in fact, the fertility of the country depends almost entirely upon the floods.

It is very probable that these waters might be utilized to a much greater extent by establishing large reservoirs in the adjacent valleys, which would be filled during the rising of the floods; and when these latter have subsided, the stored-up water could be discharged during the dry seasons for irrigation, navigation, and numerous other purposes. According to the present system, a vast quantity of water is allowed to waste, and the means of cultivating a large additional tract of country, now a desert, is lost. This object might be carried still farther by improving the channel of the Nile up to the great lakes of Albert and Victoria Nyanza, for the most part now a marshy, pestiferous district; this will very probably be done, as the subject becomes better understood; indeed, it is surprising how little the advantages which nature offers us in this respect are turned to account.

The delta of the Nile, like other rivers of the same class and magnitude under similar circumstances, advances outwards into the Mediterranean, and in proportion as it moves forward, the depth of water increases, and the width of the delta becomes greater, so that it requires a larger quantity of alluvium to maintain its progress, which becomes necessarily slower—that is, as far as concerns the alluvium brought down by the Nile. But then it must be observed, that as the delta proceeds outward, the stagnation produced by the protrusion of its apex into the Mediterranean causes a greater accumulation of alluvial matter to be deposited on both sides of the apex, and consequently two great bays are formed, one on either side, although the shores of these bays necessarily do not advance so rapidly as the centre portion. In proportion as the several branches of the Nile advance seaward, so their courses become lengthened, and consequently the total fall or inclination of the current becomes diminished, so that it cannot keep them all open; and hence, out of the eight branches or mouths of the Nile which existed in ancient times, only two now remain—namely, the Damietta and Rosetta mouths, and these are slowly deteriorating.

Whilst upon this part of the subject, it may be advisable to make a few remarks about the Suez Canal. This great work consists of an open cutting or trench from the Bay of Pelusium (Port Said) to the Red Sea at Suez, a total length of 99 miles, 196 feet wide at top, 72 feet wide at bottom, and 26 feet deep, with side slopes of 2 to 1. At the Mediterranean end there is a rise of tide or variation in the surface of the sea of from 1 foot to 2 feet, and at the Suez end from 2 feet at neaps to 6 feet at springs.

On the Mediterranean the entrance to the canal is protected by an artificial harbour composed of two piers carried from the shore. The western pier is carried out 2400 yards in a straight line, pointing towards the north, it then inclines slightly to the east for 330 yards, so that the total length of the west breakwater or pier is 2730 yards, or 8190 feet. The eastern breakwater or pier is carried out from the shore at a distance of 1530 yards from the commencement of the western pier, and is extended in a northerly direction 2070 yards, where it terminates at 760 yards from extremity of the west pier, which constitutes the entrance. Thus the two piers enclose a space of 500 acres, with a depth within of 26 feet. This harbour is said to be well protected against the prevailing or north-west winds.

This outer harbour, called Port Said, is connected with extensive quays and basins within, from whence the canal proceeds across the isthmus. At 52 miles from Port Said there is Lake Timsah; also Lake Ismaila and the Bitter Lakes, at 57 miles from Port Said. These Bitter Lakes cover a surface of about 100,000 acres, and will always ensure a considerable draught or current from the Red Sea, to compensate for the large amount of evaporation which is constantly going on, particularly during the summer season, and is said to amount to about 250,000,000 cubic feet daily. In order to supply fresh water to Suez, Ismaila, and Port Said, a considerable channel has been made from the Nile, at Cairo, to Suez and Ismaila, and a double line of cast-iron pipes between Ismaila and Port Said, with pumping engines of the requisite power at the former place.

The entrance to the Suez end of the canal is formed by an extensive double embankment through the shoal water, increasing gradually from a width of 72 feet at bottom, to 980 feet, where there is an open tidal dock, with 26 feet depth at low water.