The exploration of Tibesti, Erdi, Borkou, and Ennedi in 1912-1917 — Reading Notes

Correcting Nachtigal's Map

Tilho's narrative is punctuated by corrections to the work of the German explorer Gustav Nachtigal, who had traversed Tibesti in 1869. At Bardai, Tilho finds an error of '50 miles in latitude and 30 in longitude' in Nachtigal's coordinates, and notes that the altitude is 'nearer 3000 than 2500 feet above sea-level.' The peaks of Toussidé and Timi, he asserts, rise to '10,000 feet,' not the lower figures previously assumed. These corrections are not mere pedantry; they reflect the expedition's core purpose of producing reliable topographic data.

Tilho also clarifies a terminological confusion: 'Tarso,' which Nachtigal used as a proper name for a specific massif, is actually 'a general term applied by the Tibestians to all mountainous regions consisting of high plateaux.' This observation reveals how local knowledge could reshape European cartographic conventions. The excerpts show Tilho taking pride in having 'fixed with a very satisfactory degree of precision' the positions of summits that Nachtigal 'had only been able to locate by guesswork.'

The Logistics of Desert Travel

The excerpts offer a granular view of the material challenges of early twentieth-century Saharan exploration. Tilho's journey to Bardai is constrained by 'want of camels,' forcing him to meet Lieutenant Blaizot on foot. At Miski, he leaves a 'little detachment' guarding 'broken-down camels' and 'last reserves of food,' a situation he describes as 'some insecurity.' These details underscore how the success of scientific observation depended on the fragile infrastructure of animal transport and supply depots.

Tilho's schedule is equally revealing: he stays only twenty-four hours at Bardai, using the night for 'astronomical observations' and the morning for 'measurements of angles on the principal peaks.' The pace is relentless, driven by the need to return to his vulnerable base camp. The narrative thus intertwines scientific ambition with the constant pressure of survival, a theme that the catalog subject 'Description and travel' only partially captures.

Local Guides and Political Context

Tilho's account includes interactions with local actors, though the excerpts provide only glimpses. His Têda guide Mohammed is 'very much upset' by news of 'fighting in the Modra valley between the Borkou troops and the hillmen,' a conflict that threatens the planned route. This passing reference hints at the political turbulence that surrounded the expedition, yet the catalog subjects do not list military or political history. The reader is left to infer that Tilho's mission operated within a colonial framework, with French troops already stationed in the region.

The meeting with Lieutenant Blaizot, 'commanding the troops of Tibesti,' is described as a 'great joy' and the 'junction so long desired between the troops of Borkou and those of Tibesti.' This language reveals that the expedition was also a military coordination effort, though Tilho frames it primarily as a geographical achievement. The excerpts do not elaborate on the nature of the 'rebels' or the broader conflict, leaving those aspects unexplored.

Readers should approach this text as a primary source that documents both the scientific ambitions and the practical realities of early twentieth-century exploration. The editorial note about transliteration systems is a reminder that the work is mediated by multiple layers of translation—linguistic, cartographic, and institutional. Pay attention to the gaps: the local voices that appear only briefly, the political conflicts that remain in the background, and the physical hardships that shape the scientific data. These silences are as instructive as the measurements Tilho so carefully records.

I kept thinking about Jean Tilho’s quiet patience with maps that refused to match the ground, and how he trusted the people who walked with him more than the lines he’d been given. It reminded me of a colder, lonelier journey, where the same trust mattered most: The Worst Journey in the World: Antarctic, 1910-1913 — Story, Setting & Ideas. Both linger like a familiar ache.