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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Troughton device c.1800
From: David C
Date: 2023 Sep 15, 19:37 -0700
From: David C
Date: 2023 Sep 15, 19:37 -0700
An interesting device but outside my price range!
Is it a nomogram involving two verniers at right angles to each other? The graticle on the curved plate does not appear to have any scales so it may be a link between the two verniers and does not give any values. I will state the obvious and say that it calculates a trigonometrical function. 0 on the horizontal vernier is 5 on the vertical vernier.
David C
