At the beginning of the 19th century, the Lille region (mainly Lille, Roubaix and Tourcoing) was already marked by industrialisation. The increase in the number of factories worsened the problem of pollution, particularly air pollution. The disagreeable and unhealthy nature of the fumes produced by steam engines was recognised by the decree of 1810. Then, complaints against these fumes multiplied, as they were accused of spreading a foul odour, causing disease and destroying vegetation. Moreover, this source of pollution did not only harm the air, but also the water, the soil and the buildings. In the middle of the 19th century, the fumes became a major concern for the inhabitants as well as for the local political authorities. Under the influence of the London Smoke Abatement Act of 1853, they called for changes in legislation to improve the quality of the air and the environment in Lille and its surroundings. Furthermore, scientists, politicians and engineers proposed to generalise the use of "smoke-burning" devices, which had been made compulsory for steam engines by a decree in 1865. However, these devices were not really effective. Moreover, for industrialists, some notables (journalists, professors, scholars, etc.), but also many workers, smoke was above all a sign of prosperity and economic power. Writers also praised the chimneys and their fumes because the latter would give the Lille region its identity. Fumes was then seen, at worst as a necessary evil, at best as a blessing.