Invasion of the Sea. Jules Verne

of Gabès by a narrow canal.

       Mr. de Schaller

      “After Herodotus came Pomponius Melas, near the beginning of the Christian era, who noted the existence of a large lake named Triton (also known as Lake Pallas),¹ whose connection with the Gulf of Petite-Syrte, the present-day Gulf of Gabès, had disappeared as a result of a drop in the water level due to evaporation.

      “Finally, according to Ptolemy, as the water level continued to fall, the lake separated into four depressions—Lake Triton, Lake Pallas, Lake Libya, and Turtle Lake—known today as Chott Melrir and Chott Rharsa in Algeria and Chott Djerid and Chott Fedjedj in Tunisia. The latter two are often referred to collectively as the sebkha, or salt marsh, of Faraoun.

      “As for these ancient legends, gentlemen, which have nothing to do with precision and modern science, we can take them or leave them—and it is better to leave them. No, Jason’s ship was not driven across this inland sea, which was never connected with the Gulf of Petite-Syrte, and he could never have crossed the coastal ridge unless he had been equipped with the powerful wings of Icarus, the venturesome son of Dedalus. Observations taken at the end of the nineteenth century show conclusively that there could never have been a Sahara Sea covering the whole region of chotts and sebkha, since at some points these depressions, especially those nearest the coast, rise fifteen or twenty meters above the level of the Gulf of Gabès. That sea could never, at least during the period of recorded history, have been a hundred leagues in width, as some overactive imaginations claimed.

      “Nevertheless, gentlemen, by reducing it to the maximum size permitted by the nature of the terrain surrounding the chotts and sebkha, it would be possible to carry out the project of creating a Sahara Sea, by bringing in water from the Gulf of Gabès.

      “This, then, was the plan elaborated by a few bold but practical scientists, a plan which, after many attempts, has yet to be carried out. What I want to do now is review for you the history of this project, as well as the vain struggles and cruel setbacks that have characterized it for so many years.”

      A movement of approval could be heard in the room, and every eye followed the speaker’s hand as it gestured toward a map with large spots, which was hanging on the wall above the platform.

      The map showed the part of Tunisia and southern Algeria lying at the thirty-fourth degree of latitude and between the third and eighth degrees of longitude. The large depressions southeast of Biskra were clearly marked. They included all the Algerian chotts lying below the level of the Mediterranean Sea, known as Chott Melrir, Grand Chott, Chott Asloudje, and others, as far as the Tunisian border. Indicated on the map was a canal that joined the end of Chott Melrir with the Gulf of Gabès.

      To the north extended the plains inhabited by various tribes, and to the south lay the vast region of dunes. The principal towns and villages of the area were marked in their exact locations: Gabès, on the shore of the gulf of the same name; La Hammâ to the south; Limagnes, Softim, Bou-Abdallah, and Bechia on the strip of land lying between the Fedjedj and the Djerid; Seddada, Kri, Tozeur, Nefta in the space between the Djerid and the Rharsa; Chebika to the north and Bir Klebia to the west of that; and finally, Zeribet-Aïn Naga, Tahir Rassou, Mraïer, and Fagoussa, near the proposed Trans-Sahara Railway to the west of the Algerian chotts.

      In one glance, the audience could easily discern on the map all the depressions, including the Rharsa and the Melrir, which, once flooded, would form the new African sea.

      “But,” continued Mr. de Schaller, “whether or not nature has been kind enough to arrange these depressions in such a way as to receive water from the Gulf of Gabès can only be established after a lengthy surveying operation. In 1872, during an expedition across the Sahara Desert, Mr. Pomel, the senator from Oran, and Mr. Rocard, a mining engineer, claimed that this work could not be carried out because of the nature of the chotts. The study was taken up again in 1874, under better conditions, by Staff Captain Roudaire, in whose mind the idea for this extraordinary project first took shape.”

      Applause broke out on all sides at the mention of this French officer, who was acclaimed as he had often been already and always would be in the future. To his name, moreover, should be added those of Mr. de Freycinet, chairman of the Council of Ministers, and Ferdinand de Lesseps, who later recommended this gigantic undertaking.

      “Gentlemen,” continued the speaker, “we must go back to that early date to witness the first exploration of this region, which is bounded on the north by the Aurès Mountains, thirty kilometers south of Biskra. It was in 1874 that this daring officer developed the plan for an inland sea, a plan to which he would devote so much effort. But could he have foreseen the many obstacles that would arise, and which might be beyond his ability to overcome? Nevertheless, it is our duty to give this brave man of science the recognition that he deserves.”

      After the first studies had been carried out by the minister of public education, who was the sponsor of this undertaking, Captain Roudaire was officially put in charge of several scientific missions having to do with the exploration of the region. Precise geodesic measurements were carried out, which made it possible to map the contours of that part of the Djerid.

      As a result, legend had to give way to reality: this region had never been, as was once believed, a sea connected to the Gulf of Gabès. Further, it was discovered that this depression in the earth’s surface, which was once viewed as being completely floodable from the Gabès ridge to the farthest chotts of Algeria, could in fact be flooded only over a relatively small part of its total area. But the fact that the Sahara Sea would not be as large as popular belief would have it was no justification for abandoning the project.

      “In principle, gentlemen,” said Mr. de Schaller, “it was apparently thought that this new sea might cover an area of fifteen thousand square kilometers. From this figure, we have had to subtract five thousand for the Tunisian sebkha, which lie above the level of the Mediterranean. In fact, according to Captain Roudaire’s calculations, no more than eight thousand square kilometers of Chott Rharsa and Chott Melrir, which lie some twenty-seven meters below the level of the Gulf of Gabès, can be flooded.”

      Moving his pointer over the map and explaining each detail of its panoramic view, Mr. de Schaller guided his audience through that part of ancient Libya.

      First of all, in the sebkha region, starting at the coast, the area above sea level ranges in height from 15.52 meters to 31.45 meters, the highest point being near the Gabès ridge. Farther inland, the first large depression, some forty kilometers in length, is the basin of Chott Rharsa, two hundred and twenty-seven kilometers from the sea Then the ground rises for a distance of thirty kilometers, as far as the Asloudje ridge, and drops for the next fifty kilometers, as far as Chott Melrir, most of which could be flooded over a distance of fifty-five kilometers. This point, at longitude 3°40’, is four hundred and two kilometers from the Gulf of Gabès.

      “This, gentlemen,” continued Mr. de Schaller, “is the geodesic work that has been carried out in those regions. If the eight thousand square kilometers that lie below sea level are definitely capable of receiving water from the gulf, would it not be beyond the power of man, given the nature of the terrain, to dig a canal two hundred and twenty-seven kilometers long?”

      After making many probes, Captain Roudaire did not think so. As Maxime Hélène explained in an excellent article written about this time,² it was not a question of digging a canal across a sandy desert, as at Suez, or through limestone mountains, as at Panama and Corinth. Here the terrain is not nearly as solid as that. It would be a matter of digging through a salty crust, and a drainage system would keep the ground dry enough for this work to be carried out. Even on the ridge of land between Gabès and the first sebkha, a distance of twenty kilometers, the pick would encounter only a layer of limestone thirty meters thick. All the rest of the digging would be in soft ground.

      The speaker continued, summing up very precisely the advantages which, according to Roudaire and his successors, would result from this gigantic undertaking. In the first place, the climate of Algeria and Tunisia would be appreciably improved. Under