Lefebvre, charged (1839) with political and geographical missions, and Captains Galinier and Ferret, who completed for him a useful triangulation and survey of Tigre and Simen (1840-1842).
The metamorphic rocks compose the main mass of the tableland, and are exposed in every deep valley in Tigre and along the valley of the Blue Nile.
A Greek inscription at Adulis, no longer extant, but copied by Cosmas of Alexandria, and preserved in his Topographia Christiana, records that Ptolemy Euergetes, the third of the Greek dynasty in Egypt, invaded the countries on both sides of the Red Sea, and having reduced most of the provinces of Tigre to subjection, returned to the port of Adulis, and there offered sacrifices to Jupiter, Mars and Neptune.
Among his many works are: Grammatica syriaca (1867-1870); Vocabulary of the Tigre language (1868); Das Gedicht vom Hiob (1871); Die Prophetie des Joel and ihre Ausleger (1879); Die Saadjanische Ubersetzung der Hohenlieder ins Arabische (1882); Chrestomathia targumica (1888); Historia artis grammaticae apud Syros (1889); Ein samaritanisches Fragment (1893); Idee and Grundlinien einer allgemeiner Geschichte der Mystik (1893).
As, however, the Italians became more and more friendly with Mangasha and Tigre the apprehensions of Menelek increased, till at last, in February 1893, he wrote denouncing the Uccialli treaty, which differed in the Italian and Amharic versions.