The monumental work of Philibert Vasserot, which has been conserved since 1900-1901 in Paris at the Historical Centre of National Archives, is, for those who study the history and aspects of the Paris soil and building in the early nineteenth century, a kind of ‘customary’ in Paris before Haussmann, so familiar that he does not come from the outset with the idea of studying it for himself, especially as his ‘historic destin’ has made it an inexhaustible source of urban history and archaeology, and not the fi...