Talk:Reflecting instrument

A pillar sextant is NOT a sextant on a stand

Typical Wikipedia. Didn't this get discussed a few years ago on NavList? A "pillar sextant" is one specific type of sextant manufactured from the late 18th through the early 20th centuries. It's a sextant with two frames (two separate sextant-shaped plates) separated by a dozen or so identical short metal cylinders or "pillars" which together create a light, but very stiff frame, desirable for consistent angular measurements. The article says this very clearly in one paragraph. But then below that paragraph, there's this odd spot where it states that a pillar sextant can also be a sextant on a stand. Nonsense. That's just wrong. Some people in recent years have erroneously said, "oh look a sextant on a stand... wait, there's a term for that... I think it's called a 'pillar sextant'". These errors do not suddenly redefine the phrase "pillar sextant". If I publish a book on beginning meteorology and print a picture of bunch of puffy cumulus clouds and label them "cirrus clouds", do those clouds instantly become cirrus clouds? Of course not. Similarly, a few erroneous uses in recent decades have not changed the long-standing meaning of the phrase "pillar sextant".

Also, isn't this section itself just trivia? Does this section (with the correct and the erroneous definitions of pillar sextant) even need to be a separate part of the article given that the pillar sextant is correctly described in the main text of the article?173.120.34.42 (talk) 02:52, 2 March 2011 (UTC)

The reference is for an instrument made and so named around 1800 - the same time frame as the double frame sextant (which, in turn, is a better and more descriptive name than "pillar sextant"). This usage is not new apparently. The mention of this fact does not remove the more-common meaning of the name. Whether this usage is in fact erroneous is debatable. --Michael Daly (talk) 18:46, 2 March 2011 (UTC)