H. G. Wells 
The First Men in the Moon [EPUB ebook] 

The books tells the story of a journey to the moon by the impecunious businessman Mr Bedford and the brilliant but eccentric scientist Dr Cavor. On arrival, Bedford and Cavor find the moon inhabited by a race of moon-folk the two call "Selenites." The novel can also be read as a critique of prevailing political opinions from the turn of the century, particularly of imperialism.