titel | Bubble sextant type AN 5854.1 F.S.S.C no. 88-S-375 serienr. VZ 4081 |
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inventarisnummer | MLD/0048 |
collectie | Historische Verzameling Marineluchtvaartdienst |
museum | Marinemuseum Den Helder |
maker | Bausch & Lomb Optical Co. |
omschrijving | Zwart, metalen Bubble sextant. Met een plaatje op de achterzijde: "U.S. patent 1,674,550 2,306,874 pat. pending". Op de zijkant is het nummer "R 88-S-375" geschilderd. Op de onderzijde een plaatje: "sextant bubble type. BU Aero U.S. navy AN 5854.1 F.S.S.C no. 88-S-375 serienr. VZ 4081 Bausch & Lomb Optical Co. Rochester, N.Y., U.S.A". The basic idea is that from an aircraft, the horizon no longer serves as a reference for horizontal as it does at sea level. So a bubble level was used instead. A bubble attachment is a special sextant telescope containing an internal artificial horizon in the form of a small spirit level whose image, replacing the visible horizon, is superimposed with the image of the body. Bubble attachments are expensive and not very accurate because they require the sextant to be held absolutely still during an observation, which is difficult to manage. A sextant equipped with a bubble attachment is referred to as a bubble sextant. Special bubble sextants were used for air navigation before electronic navigation systems became standard equipment. |
afmetingen | hoogte 10.5 cm breedte 14 cm lengte 20 cm |
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