In France, the atmospheric enthusiasm on the 1840s encouraged the government to finance an official trial of the system, the Ministry of Public Works clearly concerned about keeping abreast of new railway technologies. The trial was carried out by the Paris-Saint-Germain Company, and this second part of the article examines the history of its line built from Le Pecq to SaintGermain- en-Laye. It was operational from 1847 but its abandon, in 1860, marked the end of the atmospheric caper in Europe.