In early 1892 he was sent by the Comité de l'Afrique française to the French Congo in order to reinforce an exploratory mission led by Jean Dybowski (1856–1928).
On 29 June Maistre and a handful of Europeans, departed from their position on the Kémo (a tributary of the Ubanghi) [1] in order to explore largely unfamiliar regions of the continent's interior.
On the expedition he would journey over 5000 kilometers, engaging in numerous treaties with African chieftains as a means to consolidate French influence in the region.
In the interior he recognized that the Chari and Logone Rivers were navigable year-round, as well as primary access routes to/from the Lake Chad area.
As a result of the mission, he published two books: After his return from Africa he settled in Villeneuvette, where he worked as a manager in a family-owned factory.