The Compagnie du chemin de fer métropolitain de Paris (CMP) now signs its documents, including this 1938 plan, with a new red M logo on a blue circle with the inscription "métro".
You will note on this plan, the existence of a shuttle linking the termini of lines 3 and 7 (today 3 bis and 7bis), operated from 1921 to 1939. In 1951 it was used as an experimental ground for automatic piloting, then from 1952 to 1956 for the world's first prototype of a pneumatic metro.
Also to be observed, the old line 14 linking Invalides to Porte de Vanves, until 1976. It then merged with line 13 thanks to the construction of a new section: Invalides to Saint-Lazare via Miromesnil.
Reference : RABC20011