RARE ITALIAN POLEMOSCOPE, 1750, signed on a silver band, “In Galleria D.S. M.C. 1750.” Made of turned (probably tropical) wood, bound in (now quite darkened) silver, this optical instrument measures 1-13/16″ (47 mm) tall by 1-7/16″ (36 mm) outside diameter. It has viewing port and observation port, with internal oval glass mirror set at 45°. The other end is set with a circular plane glass mirror. Condition is fine except for considerable loss of silvering to the mirrors.
In use the polemoscope, or “jealousy glass,” permits very discreet viewing at right angles of, for example, patrons at the opera. This unusual example, with its simple second mirror, allows one to also view to the rear, surreptitiously, or to check one’s own makeup.
We have not identified the maker. The “Galleria” address suggests the shops in the fine arcades of northern Italy, for example in Milan and most notably in Turin, where the Galleria built by the famous architect Amedeo de Castellamonte in 1673 still exists, and even includes an ongoing shop established in 1707 (thanks to Alberto Lualdi for this insight). It is tempting to connect the initials with the workshop of the optical instrument maker Domenico Selva (and his son Lorenzo), quite active in mid-18th century Venice (albeit a city of arcades termed “Procuratie” and not “Galleria”). But perhaps we have here tangible evidence of an unrecorded maker.
Ask the Dealer
David and Yola Coffeen both have enjoyed academic careers, as planetary astronomer and as linguist/educator. But since 1982 (yes, 1982!) they have been full-time dealers in early scientific and medical instruments, under the name Tesseract. Selling primarily by catalogue (over 100 issued so far) they also have a web presence at www.etesseract.com, and can be contacted at firstname.lastname@example.org.