This small booklet was purposely bound in a crude manner, like a small press printing done for somebody who does not have much money to spend. Compiled by Axel Wappendorf, it describes various strange means of transportation; some of them in actual use in the Obscure Cities, while others are only projects. The only conclusion that can be reached is that Obscure engineers are extremely imaginative, but perhaps lacking a bit of practical sense…
Only 800 copies were originally made. Like Le mystère d’Urbicande, the Encyclopedia is now rare in the extreme, and very much sought after by collectors. Because of the weak bindings, pages of this book have a tendency to fly off, and many copies are incomplete. Fortunately, most of the images have been reproduced in Le guide des Cités. Although few readers have actually seen it, the existence of the Encyclopedia has been mentioned in several of the stories and every devout reader knows of its existence.