He was a strong believer in opening up Africa to trade through peaceful means, and thus bringing the benefits of French civilization to the natives while gaining commercial profits for France.

Although Soleillet had no scientific training and did not speak the local languages, he was willing to travel on foot with little baggage and few companions, and thus generally avoided being robbed.

Despite this, Soleillet found himself the spokesman for groups interested in a Trans-Saharan railway, and was subsidized to make an expedition from Senegal into the Western Sudan in 1878.

He became partner of a small manufacturer of gold and silver lamé fabrics designed for the North African market, travelled to Algeria and fell in love with the country.

[2] In October 1871 Soleillet wrote to the Minister of Public Works about bringing trade from the Central Sahara and West Sudan to the Algerian markets.

[9] There he gained the friendship of Auguste Warnier, the Deputy for Algeria, who introduced him to General Hippolyte Mircher (1820–78), another specialist in the Sahara.

[7] Soleillet said later the goal of his trip from September 1872 to April 1873, and from 1873 to 1874, was to determine the needs and resources of the countries with which France would open commercial links and bring the benefits of French civilization.

[8] He thought that taking astronomical observations might make the natives suspicious, so just used a chronometer to estimate the duration of each stage of the journey and took the general direction of the route several times a day.

[3] Soleillet was accompanied on his trip to In-Salah by four merchants who brought goods from Algiers such as sugar, matches, candles and shot pellets.

The interior merchants had nothing of great interest to sell, apart from second-rate ostrich plumes and ivory, and poorly salted hides.

Soleillet only spent a few hours at In-Salah, where the notables refused to meet him or read his messages, and made it clear their loyalty was to the Sultan of Morocco.

I felt then a feeling that it is easy to indicate, but that it would be impossible to define ...[14] Of In-Salah he reported that "the trade in Negro slaves is undertaken on a large scale throughout the Sahara.

"[15] Soleillet considered that the abolition of slavery would solve nothing, since the African tribes would continue to make war, and if they could not sell their captives would simply massacre them.

He proposed that the solution was for France to buy the slaves and use them to repopulate the Sahara, where they would be introduced to agriculture and the arts and the civilization of Europe.

They would be helped to build towns and villages and after a commitment of ten years, for example, would be granted their liberty, their homes, the lands they had cultivated and their work tools.

In February 1877 General Chanzy encouraged the Missions Commission to give Soleillet the subsidy he had requested to go to Timbuktu in one of the annual native caravans.

[19] In 1878 Governor Louis Brière de l'Isle of Senegal charged Soleillet with an official mission to Ségou in the Western Sudan funded by his administration, with the support of the merchants of Saint-Louis.

[20] The purpose was to collect information about the economic potential of the Western Sudan and about how France could expand its influence in the region.

[23] At Kooniakary Soleillet found several Futanke who could speak some French, and these were used to watch him and make sure he was told only the official line.

[24] However, Soleillet heard of the rebellion from one of the dissident brothers, whom he met at Dialla, and from then on constantly tried to get information about any challenges to Amadu.

[28] He said that a railway could easily be constructed from the Senegal to the Niger since the land was level, fertile and inhabited only by two races, the Bambara and the Solenké [Soninke?].

[19] In April 1879 the Administrative Council of Senegal said that his visit to Ségou had been successful, granted him 20,000 francs in subsidies, and announced that he was in charge of a new mission.

[34] In February 1881 a column commanded by Captain Joseph Gallieni, exploring a future route from the Senegal to the Niger, was stopped by Ahmadou Sekou, stripped of its baggage and held captive before being released for ransom.

[34] The government said that anyone who visited the tribes of West Africa must have a solid understanding of the Arabic language and the Moslem religion.

[38] The commercial station at Obock was to receive the products of Shewa, including ivory, coffee, hides and the musk of civets for use in perfume.

[40] The king of Shewa gave him large tracts of land and granted him a concession to build a railway to the Gulf of Aden.

[36] He described the trade of Bonga as primarily slaves, coffee, musk of civets, coriander and ivory, with a turnover of $200,000 and $300,000 a year.

[31] Arthur Rimbaud had been established at Harar in 1881 as the agent of an Aden-based company belonging to Alfred Bardey of Lyon.

The arms were landed at Tadjoura in February, but could not be moved inland because Léonce Lagarde, governor of the new French administration of Obock and its dependencies, issued an order on 12 April 1886 prohibiting the sale of weapons.

The more complete version included his travel journal and letters addressed to Gabriel Gravier(fr), honorary president of the Normandy Geographical Society, who published it after Soleillet's death as Voyages en Éthiopie.