the city of paris decided in 1925 to connect three lines to line 10. to this end, many possibilities were examined. it was first envisioned to extend the line to "bastille" via "place jussieu", to complement the creation of a circular line. however the abandonment of the creation of a circular line made this expansion of little use and would require an underwater section very close to one already planned for line 7 toward "pont de sully". eventually, the city chose to limit the line to "jussieu" on the rive gauche to create a connection with line 7.