NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Calibrating a sextant scale
From: Frank Reed
Date: 2007 Nov 23, 00:24 -0500
From: Frank Reed
Date: 2007 Nov 23, 00:24 -0500
On collimating tables... Might as well go to the original. You can read all about one of the earliest in the Proceeding of the Royal Society from 1867/68. Here's the first few lines of the article: "I. "Description of an Apparatus for the Verification of Sextants designed and constructed by Mr. T. Cooke, and recently erected at the Kew Observatory." By BALFOUR STEWART, LL.D., Superintendent of the Kew Observatory. Received May 9, 1867. In order to test the accuracy of graduation of a sextant, it is necessary to have a series of well-defined objects, the angular distances between which must be accurately known. The sextant under trial is made to measure these angular distances ; and the results thus obtained, when compared with the correct values of these distances (supposed to be otherwise determined), will give at once the error of the instrument. " Here's a link to the article on google books: http://books.google.com/books?id=tKsOAAAAIAAJ&pg=PA2 I am attaching a diagram from the article. I've changed the the image in an effort to make it a little easier to figure out. -FER --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
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