The construction of an artificial language would become one of Wilkins's main obsessions. He worked on the project in the 1650s and 1660s, and it culminated in what is Wilkins's most imposing publication, An Essay concerning a Real Character, and a Philosophical Language, finally published in 1668 after the disastrous truncation of a first attempt by the Great Fire of London. This large folio was a flagship venture for the early Royal Society, and Wilkins enlisted several young men, including John Ray, Francis Willughby, Samuel Pepys, and Robert Hooke, to help him construct the extensive tables on which the whole language was to rest. In Mercury, Wilkins had proposed merely an international script; in the Essay this had become a fully effable language. Wilkins devised a special character for his language, and he even commissioned a special fount for his new script, so that the relevant sections of the book could be set in metal type. It was an extraordinary venture, and everyone had something to say about it. But it was not a success. There were too many problems both with the deep assumptions Wilkins made about classification and meaning, and with the sheer practicalities of devising tables that in theory contained everything one might want to think and say.
