A trade catalog published in English by Bardou in 1911 recommended their line of telescopes with 3-inch lenses for terrestrial viewing of scenery such as mountains, as well as for basic astronomical observations, such as viewing the topography of the moon and features of the planets not visible to the naked eye such as Saturn’s rings and Jupiter’s moons.
A similar telescope in the collection of the Smithsonian Institution is described on their website as follows:
Maison Bardou, for many years a leading manufacturer of small telescopes for education and recreation, was established in Paris in 1818. The firm displayed their wares at the Centennial Exhibition in Philadelphia in 1876. This telescope has a brass tube assembly marked “A. BARDOU PARIS,” an objective lens of 3½ inch aperture and 52 inch focus, and a wooden tripod. The signature indicates that it was made around between 1878 and 1895. James W. Queen & Co., the leading purveyor of scientific instruments in the United States, offered similar instruments for $175.
Engraved at end of barrel: A BARDOU/ PARIS
Condition: Generally fair to good, brass uniformly patinated, overall suitable as a handsome prop rental piece.
Bardou & Son. The Telescopes of Bardou & Son, Paris, France. Paris: 1911. Reprinted on Instruments for Science: Scientific Trade Catalogs in Smithsonian Collections, 1800-1914.” http://www.sil.si.edu/digitalcollections/trade-literature/scientific-instruments/files/51784/index.htm (29 November 2004).
“Bardou Refracting Telescope.” National Museum of American History. https://americanhistory.si.edu/collections/search/object/nmah_1183733 (3 October 2019).