The association first employed John Ledyard (who had previously made an extraordinary journey into Siberia) to cross Africa from east to west on the parallel of the Niger, and William Lucas to cross the Sahara to Fezzan.
Lucas went from Tripoli to Mesurata, obtained some information respecting Fezzan and returned in 1789.
Captives were brought thence to the slave market of Kuka in Bornu, where, after being bought by dealers, they were, to the number of about 10,000 annually, marched across the Sahara to Murzuk in Fezzan, from which place they were distributed to the northern and eastern Mediterranean coasts.