François Élie Roudaire

Operating south of Biskra, in Constantine Province, he explored the region's chotts, and was one of the first to accurately measure their depth, noting that many lay below sea level.

[1][2] Having discovered many locations far below sea level (up to 40 metres (130 ft)), Roudaire became convinced that a vast depression once extended to the salty Gulf of Gabès and corresponded to a geographic feature known at the time of Herodotus as Lake Tritonis (also known as the Bay of Triton).

[4] Ferdinand de Lesseps, who was instrumental in the creation of the Suez Canal, adopted the idea along with several other writers, scholars and politicians.

[5] While there was initially general enthusiasm for the project, further surveys discovered that one of the chotts that Roudaire and de Lesseps had proposed digging a canal to was, in fact, above sea level.

[5] Roudaire and Ferdinand de Lesseps fell back on private funding and founded the Society for the Study of African inland sea later that year to continue their pursuit of the project.