Contains: watercolour of mine shafting and tunnels; illustrated title page; a 1:800 scale ms. map view of the mine workings built up from 12 superimposed coloured map sections with cutouts, each section representing a different level of the workings and the whole producing a perspective effect; an manuscript account (in French) of the geology and history of the mines up to 1776; index and 3 leaves of coloured vertical section drawings.