CAPTAIN DESOMBRE’S “BOUSSOLE GUIDE PANTOMETRIQUE,” French, c. late 19th century. Constructed by M. Houlliot, of 60 rue Notre-Dame-de-Nazareth in Paris (according to the instruction booklet), and numbered “28,” the lacquered-brass-cased compass is 2-1/4″ (5.5 cm) in diameter, mounted with pendant ring and pin gnomon / stylus on fine chain. The lid is hinged, and sets up as an equinoctial sundial adjustable against a folding arc for all latitudes from 0° to 70°. Both sides of the inclined cover are divided with twice-12 hour scales for use with the gnomon mounted from either side (summer and winter respectively). The inner dial face is plated to serve as a sighting mirror. The glazed compass itself is set with needle, circumferential scale divided every degree to 360° and rotatable (by external holes) for magnetic offset, and with manually rotatable needle indicator atop the glass. Condition is excellent throughout. Included is the original 64-page instruction booklet with light wear and browning. Not present is an auxiliary transparent protractor.
Desombre was an infantry captain who received a patent for his “pantométrique” compass in 1893. Houilliot is listed by Marcelin as compass maker from 1865 until at least 1901. The device was recommended for its portability and its ability to determine directions of both magnetic north and geographic north. An unusual compass in exceptional condition.
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 [email protected]