The historiography of Paris has for long now taken it for granted that great industry was expelled from the capital in the course of the 19^th century. It was not the case. The demonstration is based less on the statistics than on the relationship between the Parisian industrialists and the political power. Until 1848, the central districts of Paris remained districts with factories and the power did not hesitate to protect and stimulate industrialization. It all changed in 1848: the political authorities wished to force out the factories because of the danger the workers employed there now represented. However in the 1850s they could not fail to recognize the little impact they had on industrialists. The famous episode, after 1860, of the dispute between the préfet Haussmann and the industrialists of the annexed area constitutes one more development of the willingness to expel industry. Haussmann tried, in the short term, to impose on manufacturers the city duties on certain incoming goods (octroi) applicable in Paris. But the industry in the annexed districts was at no time subjected to the entire taxes due in ancient Paris: economical realism on part of the Emperor or fear of the working class reactions at the end of the 1860s? The new Paris City Council where the economical interests were well represented, settled the issue in 1872. A compromise was reached: industry had to pay but only low taxes that in no way hindered business. This could only favour the industrial development of Paris, at its peak in 1900. In their conflicts with politicians obsessed by their fear of workers, the industrialists remained through the 19^th century masters of the game.