African explorer; born in London Sept. 22, 1851; died at sea Nov. 20, 1876. After traveling in the United States (1872) and Egypt (1873), he organized an expedition to explore the Kongo. He left London Sept. 2, 1875, and arrived at Khartum in Jan., 1876, leaving that place in the following April. He next went with Colonel Gordon to the Albert Nyanza, and navigated the northern part of the lake in the first steamboat ever launched on it. He returned to Khartum in Aug., 1876, and reached Suakim on Nov. 18 of that year. In connection with this journey, Lucas compiled a vocabulary of Bisharin words, which was published in the "Journal of the Anthropological Institute."
In the same year (1876), against the advice of General Gordon and his staff, Lucas attempted to cross Africa, but, becoming sick and paralyzed, he soon had to return to Khartum. After lying ill for three months, he died on a steamboat between Suakim and Suez, and was buried at Jiddah.