Wikipedia page about this book: https://en.wikipedia.org/wiki/Five_Weeks_in_a_Balloon

Publisher's note: "Compiled in French by Jules Verne, from the original notes of Dr. Ferguson; and done into English by "William Lackland."
Dr. Ferguson is the fictional protagonist. William Lackland is the pseudonym of the anonymous translator, used by the New York publisher for this 1869 edition, as archived at the Smithsonian Institution Libraries, cf.:
http://www.sil.si.edu/imagegalaxy/imagegalaxy_imageDetail.cfm?id_image=7666

Release date is 2002-11-01

Judy Boss and David Widger

"Five Weeks in a Balloon" by Jules Verne is an adventure novel published in 1863. Dr. Samuel Fergusson, his manservant Joe, and professional hunter Richard Kennedy set out to cross unexplored Africa in a hydrogen balloon with a revolutionary altitude-control mechanism. Their journey from Zanzibar to Senegal aims to link the expeditions of famous explorers while searching for the source of the Nile. The travelers face hostile tribes, environmental dangers, and dramatic conflicts as they navigate the mysterious continent through perseverance and fortunate timing. (This is an automatically generated summary.)

Originally published: New York: Appleton & Co., 1869