Though the Hornemann, Lyons and the Denham, Oudney and Clapperton expeditions in the first half of the last century touched the fringe of the Tuareg country, the first Europeans in modern times to come into contact with the Azger group in the Fezzan were Richardson in 1847 and Barth with Richardson in 1849 and subsequent years. Barth, more particularly mentioned in the story of the penetration of Air, is in some respects even now the most valuable authority for all the Tuareg except the Ahaggaren. The first detailed work of value dedicated to the latter was that of Duveyrier, _Les Touareg du Nord_, published in 1864 after a journey through the Ahaggar and Azger country and the Fezzan. His systematic study of the ethnology of the Tuareg, his geographical work and his researches into the fauna, flora and ancient history of the lands he visited, were presented to the world in a form which has since been taken in France as the model of what a scientific book should be. Ill health was the tragedy of his life, for it prevented his return, and rendered him, as he remarked in later years, “an arm-chair explorer of the Sahara.” After visiting the Wad Righ and Shott countries in Southern Tunisia, he went to El Golea on the road to Tuat and thence turned towards Ghadames and Tripolitania. He eventually reached Ghat, and returned to the Mediterranean coast by Murzuk and Sokna, taking a more easterly road than Barth’s in 1850. Beurmann in 1862, and Dickson ten years previously, had reached the edge of the same Tuareg country, but what Barth had done for the Tuareg of Air and the south, Duveyrier did for the Ahaggaren and Azger.