I have a first attempt at a translation of a paper in french that was referenced towards the end of this thread - This seems to be the definitive paper describing the "CGS" hairspring numbering system. The original is posted in the above thread, and here is my attempt at a translation. I'm sure it can be improved, and I can supply my docx version to any one who wants to edit it. The optical character recognition and the subsequent machine translation introduced many errors, and I had