I found this at an outdoor book market and wondered if anyone else is interested in this book. It was published in 1984 by Technicmedia Editions in Besancon ISBN 2-905477-00-8 It is the history, methods, techniques, tools, and application of the cylinder escapement. I am working my way through it and winder if anyone is interested. A quick check shows that the book is available from the NAWCC Library. My initial impression is that this is the mother lode for anyone interested in repair or study on these.