Bris sextant

Bris sextant

The Bris sextant (pronEng|bɹiːs) is not a sextant proper, but is a small, inexpensive, angle-measuring device that can be used for navigation.

Sven Yrvind (Lundin) developed his Bris sextant as part of his quest for low-cost, low-technology equipment for ocean crossings. The "Bris" is a low-technology, high-precision, fixed-interval instrument. It's made of two narrow, flat pieces of glass (microscope slides) permanently and rigidly mounted in a V-shape to a third flat piece of glass. When the sun or moon is viewed through the V, it is split into eight images. The instrument is small and rugged enough that it can be kept in a 35mm film canister (about 2 cm radius, 3 cm tall) on a lanyard around one's neck.

The Bris sextant is calibrated at a known geographic position with a good clock and a nautical almanac. As the day passes, one works the sight reductions backwards to develop exact angles for each of the images' tops and bottoms. The Sun and Moon have approximately the same angular size from the surface of the Earth, and can use the same calibrations.

In use, one waits until an image's edge touches the horizon, and then records the time and reduces the sight using the recorded angle for that edge of the image.

Etymology

"Bris" is Swedish for "breeze". It would appear that the name "Bris" is used by Yrvind for a number of his sail boats and is a favourite of his.

External links

* [http://www.yrvind.com/ The home page of Mr Sven Yrvind] and his autobiography in Swedish, "Konstruktören" ("The Constructor"), ISBN 91-518-4154-1.
* [http://www.cassens-plath.de/catalog_web/096e_web.html Cassens-Plath catalogue] showing a two-page description of the Bris sextant.
*A three page article (not available online) on the Bris sextant appeared in [http://www.yachtingmonthly.com/ Yachting Monthly] magazine, June 1997.
*A two page article (not available online) on the Bris sextant appeared in [http://www.yacht.de/ Die Yacht] magazine, 22/1997: "Mini-Sextant: Mit einem genial einfachen Gerät verblufft Weltumsegler Sven Lundin jetzt die gesamte Fachwelt."


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Sextant — This article is about the sextant as used for navigation. For the astronomer s sextant, see Sextant (astronomical). : For the history and development of the sextant see Reflecting instruments A sextant is an instrument generally used to measure… …   Wikipedia

  • Sextant Bris — Un mini sextant Bris. Le sextant Bris est un instrument de navigation créé par un inventeur et navigateur suédois Sven Yrvind. Malgré son nom, ce n est pas tout à fait un sextant mais un petit et peu coûteux dispositif de mesure des angles qui… …   Wikipédia en Français

  • Reflecting instrument — Reflecting instruments are those that use mirrors to enhance their ability to make measurements. In particular, the use of mirrors permits one to observe two objects simultaneously while measuring the angular distance between the objects. While… …   Wikipedia

  • Sven Yrvind — (born April 22, 1939 in Gothenburg, Sweden as Sven Lundin) is a Swedish sailor, boat builder, and writer. He is famous for sailing alone across oceans in tiny boats of his own design.ailingYrvind has made several ocean crossings in his tiny boats …   Wikipedia

  • Sextante — Para el software SEXTANTE, véase SEXTANTE (SIG). Para el sextante de uso astronómico, véase sextante astronómico. Un sextante. El sextante es un instrumento que permite medir ángulos entre dos objetos tales como dos puntos de una costa o un astro …   Wikipedia Español

  • horizon — [ ɔrizɔ̃ ] n. m. • orizon v. 1360; orizonte XIIIe; lat. horizon, mot gr., de horizein « borner » 1 ♦ Limite circulaire de la vue, pour un observateur qui en est le centre. La plaine s étend jusqu à l horizon. Le soleil descend sur l horizon,… …   Encyclopédie Universelle

  • 2007 en littérature — Années : 2004 2005 2006  2007  2008 2009 2010 Décennies : 1970 1980 1990  2000  2010 2020 2030 Siècles : XXe siècle  XXIe siècle …   Wikipédia en Français

  • Chronologie de l'histoire des techniques — Si l’histoire des techniques ne peut se résumer à la seule histoire des inventions, elles en constituent néanmoins une composante importante. Au delà des grands faits historiques ou des découvertes scientifiques associées, la chronologie de… …   Wikipédia en Français

  • Chronologie des techniques — Chronologie de l histoire des techniques Si l’histoire des techniques ne peut se résumer à la seule histoire des inventions, elles en constituent néanmoins une composante importante. Au delà des grands faits historiques ou des découvertes… …   Wikipédia en Français

  • Expedition Endurance — Expédition Endurance Pour les articles homonymes, voir Endurance (homonymie). Le trois mâts l Endurance qui a donné son nom à l expédition …   Wikipédia en Français

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”