Details
In 1855, Jose da Fonseca and Pedro Carolino sat down to write an English phrasebook for Portuguese students.
There was just one problem: they didn't know English. Even worse, they didn't own an English-to-Portuguese dictionary. What they did have, though, was a Portuguese-to-French dictionary and a French-to-English dictionary. Perhaps the worst foreign phrasebook ever written, the resulting linguistic train wreck was first published in 1855 and became a classic of unintentional humor.
Mark Twain, prefacing an American edition, marveled of its 'miraculous stupidities' that 'Nobody can add to the absurdity of this book, nobody can imitate it successfully, nobody can hope to produce its fellow; it is perfect.'