The ill-fated mountaineer George Mallory's only book was "Boswell the Biographer"?
An Account of Corsica (1768)
After having travelled around Germany, Switzerland and Italy for a year, Boswell decided to go to the mediterranean island of Corsica in the fall of 1765. The island was at the time the scene of sporadic skirmishes between occupational forces from Genoa and France on the one side and a Corsican independence movement led by General Paoli on the other. Boswell gained passage from Italy to Corsica on an English ship, and joined only by his man-servant travelled to the interior of the island and the stronghold of the rebel forces. Here he met and befriended the rebel general, and took extensive notes of his visit, before he left again for the European mainland.
In 1768 Boswell published his account of the visit and of his meeting with Paoli, who had by then gone into exile in London and who was to be a lifelong friend of Boswell's.
The "Account of Corsica" secured Boswell's fame 23 years before the publication of his magnum opus the Life of Johnson, and he was known in wide circles as Corsica Boswell until his death.
The first and second editions were both published in 1768.
A complete an thoroughly annotated edition of Boswell's original work was published by Oxford University Press in 2006, edited by James T. Boulton and T. O. McLoughlin.
It is possible to acquire an original 1768 first edition of the book today, although they sell for about £400. Be aware that both the first and second editions of the book were published in 1768. These and later editions in all price ranges are available via AbeBooks.