{"product_id":"sextant-with-artificial-horizon-f5165-001","title":"Sextant with artificial horizon","description":"Black-lacquered brass frame, wooden handle, and a hollow tube at the back of the frame for a stand. Signed on the limb 'Hurlimann, Ponthus \u0026amp; Therrode, succ.rs ÔòáÔò® Paris (2975)', and on the artificial horizon 'Ponthus \u0026amp; Therode Paris'. Bronzed limb with inlaid silver scale from -5 to 130 by 20', measuring to 108. Silver vernier to 10'', zero right. Index glass (large) and horizon glass (large with hole in the centre) adjustment by detached key (missing). Three index shades (red, green, orange), two horizon shades (both orange), on the outside of the artificial horizon. Double ended tangent screw on front of the index arm, clamp screw on the back. Magnifier (single lens) on 70 mm swivelling arm, frosted glass shade. Telescope bracket without adjustment. Telescope (10 mm) erect image, with wide objective lens (star finder). Radius 5,5'' (143 mm). Box missing.\u003cbr\u003e\u003cbr\u003eThe artificial horizon consists of an airtight housing containing a gyroscope that can be locked with a lever mechanism. The gyroscope has a glass through the body, with a series of horizontal lines. The gyroscope is propelled by an air pump (missing). Air gauge calibrated from 0-76 cm of mercury.\u003cbr\u003e\u003cbr\u003eThis is the improved Admiral Fleuriais (1840-1895) artificial horizon.\u003cbr\u003e\u003cbr\u003eThere is an earlier version of the gyroscopic horizon in the collection, ACO1514.\u003cbr\u003eHurlimann Ponthus \u0026amp; Therrode","brand":"prodigi","offers":[{"title":"Fine art poster \/ XS: 30 x 20cm \/ none","offer_id":57029300683134,"sku":"GLOBAL-FAP-8X12","price":22.95,"currency_code":"GBP","in_stock":true},{"title":"Fine art poster \/ S: 45 x 30cm \/ none","offer_id":57029300715902,"sku":"GLOBAL-FAP-12X18","price":28.95,"currency_code":"GBP","in_stock":true},{"title":"Fine art poster \/ M: 60 x 40cm \/ none","offer_id":57029300748670,"sku":"GLOBAL-FAP-16X24","price":38.95,"currency_code":"GBP","in_stock":true},{"title":"Fine art poster \/ L: 75 x 50cm \/ none","offer_id":57029300781438,"sku":"GLOBAL-FAP-20X30","price":54.95,"currency_code":"GBP","in_stock":true},{"title":"Fine art poster \/ XL: 90 x 60cm \/ none","offer_id":57029300814206,"sku":"GLOBAL-FAP-24X36","price":69.95,"currency_code":"GBP","in_stock":true},{"title":"Fine art poster \/ XXL: 150 x 100cm \/ none","offer_id":57029300846974,"sku":"GLOBAL-FAP-40X60","price":82.95,"currency_code":"GBP","in_stock":true},{"title":"Framed picture \/ XS: 40 x 30cm \/ none","offer_id":57029300879742,"sku":"MUS-CFPM-12X16","price":59.95,"currency_code":"GBP","in_stock":true},{"title":"Framed picture \/ S: 60 x 45cm \/ none","offer_id":57029300912510,"sku":"MUS-CFPM-18X24","price":79.95,"currency_code":"GBP","in_stock":true},{"title":"Framed picture \/ M: 75 x 50cm \/ none","offer_id":57029300945278,"sku":"MUS-CFPM-20X30","price":119.95,"currency_code":"GBP","in_stock":true},{"title":"Framed picture \/ L: 90 x 60cm \/ none","offer_id":57029300978046,"sku":"MUS-CFPM-24X36","price":159.95,"currency_code":"GBP","in_stock":true},{"title":"Framed picture \/ XL: 100 x 70cm \/ none","offer_id":1748122665004,"sku":"MUS-CFPM-28X40","price":204.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Standard: 6 x 4in \/ Single","offer_id":57029301010814,"sku":"GLOBAL-POST-MOH-6X4","price":1.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Standard: 6 x 4in \/ 10-pack","offer_id":57029301043582,"sku":"GLOBAL-POST-MOH-6X4-10","price":14.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Standard: 6 x 4in \/ 20-pack","offer_id":57029301076350,"sku":"GLOBAL-POST-MOH-6X4-20","price":24.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Large: 7 x 5in \/ Single","offer_id":57029301109118,"sku":"GLOBAL-POST-MOH-7X5","price":2.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Large: 7 x 5in \/ 10-pack","offer_id":57029301141886,"sku":"GLOBAL-POST-MOH-7X5-10","price":19.95,"currency_code":"GBP","in_stock":true},{"title":"Postcard \/ Large: 7 x 5in \/ 20-pack","offer_id":57029301174654,"sku":"GLOBAL-POST-MOH-7X5-20","price":29.95,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Standard: 6 x 4in \/ Single","offer_id":57029301207422,"sku":"GLOBAL-GRE-MOH-6X4-BLA","price":2.5,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Standard: 6 x 4in \/ 10-pack","offer_id":57029301240190,"sku":"GLOBAL-GRE-MOH-6X4-BLA-10","price":15.95,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Standard: 6 x 4in \/ 20-pack","offer_id":57029301272958,"sku":"GLOBAL-GRE-MOH-6X4-BLA-20","price":26.95,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Large: 7 x 5in \/ Single","offer_id":57029301305726,"sku":"GLOBAL-GRE-MOH-7X5-BLA","price":3.5,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Large: 7 x 5in \/ 10-pack","offer_id":57029301338494,"sku":"GLOBAL-GRE-MOH-7X5-BLA-10","price":19.95,"currency_code":"GBP","in_stock":true},{"title":"Greetings card \/ Large: 7 x 5in \/ 20-pack","offer_id":57029301371262,"sku":"GLOBAL-GRE-MOH-7X5-BLA-20","price":33.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2785\/2654\/files\/f5165-001.jpg?v=1772722040","url":"https:\/\/prints.rmg.co.uk\/products\/sextant-with-artificial-horizon-f5165-001","provider":"Royal Museums Greenwich prints","version":"1.0","type":"link"}