P R E F A C K. 
ix 
extension of science, and which, by the encouragement it 
held out to those who should explore the central regions 
of Africa, confirmed my opinion of the importance of such 
travels, and determined me in the plan which I had already 
formed of one day attempting the discovery of Timbuctoo. 
In paying this just homage to the Geographical 
Society, I must not omit one of its most distinguished 
members, M. Jomard, President of the Central Committee 
and Member of the Institute, who, since my arrival in 
France, has without intermission honoured me with his 
valuable advice and his personal kindness, who has not dis- 
dained to unite his name with mine, and has so largely 
contributed to any success with which this narrative may 
be honoured, by enriching it with a map founded upon my 
notes, and with geographical disquisitions upon a continent, 
the study of which has long been familiar to him, both as 
a traveller and as a writer. I request him to accept this 
public testimony of my warmest gratitude. 
