French cartography reached its zenith during the 18th century, both for its scientific accuracy and its beauty. Among the most prominent figures in this great tradition are:
cartographers such as Gilles Robert de Vaugondy and his son Didier, Rigobert Bonne, Louis Charles Desnos, and the publisher Charles François Delamarche (1740-1817) who was succeeded at the head of the Maison Delamarche by his son Félix and his grandson Alexandre.

In the 18th century, a terrestrial or celestial globe consisted of two papier-mâché hemispheres joined at the equator on an internal metal axis. The resulting sphere was entirely covered with stucco, onto which were affixed twelve paper spindles and two etched polar caps. The surface was protected with a varnish, probably shellac. The sphere was surrounded by the Meridian ring and the Horizon ring.

In the globe that is the subject of our intervention, “adopted by the University / built by Delamarche / Paris / 25 Serpente Street”, “The Positions of the Stars are
have / calculated for January 1, 1950.” This celestial coordinate was indicated to allow the adjustment of astronomical variations from a fixed reference.

Improper and repeated handling, coupled with the natural deformation of hygroscopic materials, caused the sphere to shift on the horizon ring, resulting in constant abrasion of the equator line and, ultimately, losses of varnish, paper, and stucco. Furthermore, oxidation of the varnish had darkened the surface. As if this were not enough, a previous intervention had involved gluing the cracks in the paper backing with a difficult-to-remove vinyl adhesive, without correcting the unevenness, and indiscriminately adding a layer of stucco over the entire equator line, even covering the printed paper.

Therefore, the treatment of the sphere consisted, firstly, of lifting this layer of stucco and then softening and removing the vinyl adhesive. Once the tear in the papier-mâché was exposed, the edges of the paper were temporarily protected, and a new, non-toxic, reversible gluing process was carried out, along with a new coat of stucco within the limits of the losses. The missing pieces of paper were grafted with Japanese paper. The oxidized shellac was removed and replaced with a reversible protective varnish. Furthermore, the Meridian and Horizon rings were restored by straightening the cardboard, cleaning the varnish, and grafting the losses. After the restoration process, the rotating sphere no longer rubs against the rings; however, the Equator line was protected with a foam strip.