The thorough approach taken by the Oeuvre Notre-Dame provides valuable information for today's scientists: taking care to date and catalogue all work on the cathedral, it provides rare and highly detailed information on ancient stone. Insofar as concerns the stones stocked for future projects, analysis will enable us to measure the effects of the shocks they suffered during extraction, and to evaluate them over a period of time, selecting those which best resist temperature fluctuations.	(27Ko)   (30Ko)