My daughter isn't home who is fluent in French...but it does state this is tools for Dr. Chavellier, Opticien, Place du Pont Neuf 15 (address in Paris at the New Bridge). This area is full of businesses/offices (we just got back from Paris in January and walked this area quite a bit).
Here is an article about the history of The DuCray Chevallier family business - who's business was made to relocate to Paris at Pont Neuf 15!!!! They manufactured: "The engineer Chevallier (New Bridge) mainly manufactures optical instruments, physics, mathematics, marine and mineralogy. He specializes in reading glasses, binoculars theater of war and navy, astronomical telescopes, microscopes, light rooms, mirrors and stereoscopes, but also in electrical machines and pneumatic, thermometers, barometers, hygrometers, hydrometers, compass, levels, theodolites, circles, octants, sextants, etc."
http://translate.googleusercontent.com/translate_c?depth=1&hl=en&prev=search&rurl=translate.google.com&sl=fr&u=http://diaprojection.unblog.fr/2013/07/21/les-opticiens-chevalier-a-paris/&usg=ALkJrhifO-GPaBw1vwgv9R2uaAQWTnPDeQis this some type of sextant or octant?