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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant or Range-finder
From: Stephen N.G. Davies
Date: 2016 Mar 14, 10:42 +0800
From: Stephen N.G. Davies
Date: 2016 Mar 14, 10:42 +0800
They were originally called ‘sextant rangefinders’, which may explain why it was advertised as it was. They first appeared in 1914 and went through seven Marks by 1918 to improve its performance. It was never very accurate, but was still part of Royal Navy bridge equipment in the early 1960s when I can recall using one for station keeping when in formation. http://www.dreadnoughtproject.org/tfs/index.php/Waymouth-Cooke_Rangefinder has some drawings illustrating construction.
Stephen D
Dr Stephen Davies
c/o Department of Real Estate and Construction
EH103, Eliot Hall
University of Hong Kong
Office: (852) 2219 4089
Mobile: (852) 6683 3754
stephen.davies79@gmail.com
daiwaisi@hku.hk
c/o Department of Real Estate and Construction
EH103, Eliot Hall
University of Hong Kong
Office: (852) 2219 4089
Mobile: (852) 6683 3754
stephen.davies79@gmail.com
daiwaisi@hku.hk
On 13 Mar, 2016, at 3:23 am, David Pike <NoReply_DavidPike@fer3.com> wrote:Has anyone any idea what this is and how it works? http://www.ebay.com/itm/WWI-1914-Air-Sextant-Mark-II-Waymouth-Cooke/222041411459 Also, if it’s measuring waterline to mast-top angle to get range, why not use it on its side and use length? It would be more accurate. Oh! I suppose you’d need to be dead abeam the target. DaveP
