Five Weeks in a Balloon - Jules Verne

Five Weeks in a Balloon, or, A Journey of Discovery by Three Englishmen in Africa (French: Cinq semaines en ballon) is an adventure novel by Jules Verne, published in 1863. It is the first novel in which he perfected the "ingredients" of his later work, skillfully mixing a story line full of adventure and plot twists that keep the reader's interest through passages of technical, geographic, and historic description. The book gives readers a glimpse of the exploration of Africa, which was still not completely known to Europeans of the time, with explorers traveling all over the continent in search of its secrets.

Public interest in fanciful tales of African exploration was at its height, and the novel was an instant hit; it made Verne financially independent and led to long-term contracts with Pierre-Jules Hetzel's publishing house, which put out some sixty more books of his over the next four decades. (wikipedia.org)