The first Verne novel in which he perfected the "ingredients" of his later work, skilfully mixing a plot full of adventure and twists that hold the reader's interest with 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 travelling all over the continent in search of its secrets. Public interest in fanciful tales of African exploration was at its height, and the book was an instant hit; it made Verne financially independent and got him a contract with Jules Hetzel's publishing house, which put out several dozen more works of his for over forty years afterwards.
There was a large audience assembled on the 14th of January, 1862, at the session of the Royal Geographical Society, No. 3 Waterloo Place, London. The president, Sir Francis M——, made an important communication to his colleagues, in an address that was frequently interrupted by applause. This rare specimen of eloquence terminated with the following sonorous phrases bubbling over with patriotism: "England has always marched at the head of nations" (for, the reader will observe, the nations always march at the head of each other), "by the intrepidity of her explorers in the line of geographical discovery." (General assent). "Dr. Samuel Ferguson, one of her most glorious sons, will not reflect discredit on his origin." ("No, indeed!" from all parts of the hall.)