[7] In 1935, the Bardou telescope was replaced by a refractor of 153 mm diameter, equipped with a T. Cooke & Sons lens, a mount made by Maurice Manent and an electric motor.

[6] That telescope remained in use until 1950, when the society installed a new refractor with a 220 mm diameter and 3 meter focal length constructed by Antonin Benoit.

This instrument was reserved for the use of amateurs, in particular for the observation and measure of double stars as well as drawing the surfaces of planets.

[6][8] The telescopes of the Société Astronomique de France's observatory were used by numerous amateurs and professionals over its nearly 80 years of operation.

Many young amateurs who later became important professional figures in astronomy used the facility, including Fernand Baldet, Henri Chrétien, André-Louis Danjon, Ferdinand Quénisset (later an astronomer at the Camille Flammarion Observatory), Gilbert Rougier and many more.