The author's preface is devoted to a message about what interests Mercier in Paris - public and private mores, prevailing ideas, customs, scandalous luxury, abuse. "I am occupied by the modern generation and the image of my century, which is much closer to me than the vague history of the Phoenicians or Egyptians." He considers it necessary to report that he deliberately avoided satire on Paris and Parisians, since satire aimed at a specific person does not correct anyone. A hundred, he hopes. years later, his observations on the life of all strata of society living in a huge city will merge "with the observations of the century." Mercier is interested in representatives of various professions: cabbies and rentiers, milliners and hairdressers, water carriers and abbots, officers and bankers, alms and teachers, in a word, everyone who earns their living in different ways and gives others the opportunity to exist.