Talk:Corrachadh Mòr

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I'm moving this slab of text from the article itself, prior to making it more like a Wikipedia stub.

Corrachadh Mor, Ardnamurchan peninsula, Highland, Scotland is the western point of the British mainland and not the Point of Ardnamurchan. Ordnance Survey 28 September 2004 "Corrachadh longitude is 06 13 36.900 and Ardnamurchan is 06 13 34.382". Corrachadh Mor Longitude 6 Degrees 13 Minutes 36.900 Seconds West, Point of Ardnamurchan Longitude 6 Degrees 13 Minutes 34.382 Seconds West. This indicates that Corrachadh Mor is approximately 43 metres further west than the Point of Ardnamurchan. The Geodetic (Map) Datum is probably OSGB36. Ordnance Survey 17 March 2004 "Corrachadh Mor" NM"(41388.5,66202.4) on the National Grid (6 Degrees 13.68 Minutes W, 56 Degrees 42.94 Minutes N)". The foghorn of Point of Ardnamurchan is at" NM "(41499.7,67502.0) (6 Degrees 13.65 Minutes W, 56 Degrees 43.64 Minutes N)". The Geodetic (Map) Datum is probably WGS84. Corrachadh Mor is Scottish Gaelic for Great steep point. This is a rough translation. As I am no expert. It is 22 miles (36 kilometres) further west than Land's End.

Thincat 12:15, 5 August 2005 (UTC)

The latitude and longitude in the article are in ETRS89 (WGS84 is approximately 0.6 of a metre to the south-west, in January 2013. Britain is moving 2.5 centimetres north-east a year, according to Ordnance Survey.). They are obtained from the grid reference, of the letter from Ordnance Survey 17 March 2004 and using their coordinate transformer. The letter of 28 September 2004 states "06 13 36.900". However, this longitude is very probably in Ordnance Survey Great Britain 1936. Since they appear to be very close to the conversions sent to me by OS, from National Grid to OSGB36 latitude-longitude and ETRS89 latitude-longitude. Ordnance Survey 23 June 2006 "141388.5, 766202.4" = "OSGB36 6°13'36.88W", "ETRS" "56°42'56.20N" "6°13'40.6W". Ordnance Survey Coordinate transformer, 141388.5, 766202.4 = ETRS89 56°42'56.20328"N 6°13'40.59731"W. If 6°13'36.9"W were in ETRS89/WGS84, it would be 62 metres further east than 6°13'40.59731"W. When I use Memory-Map 1:25,000, 6°13'40.59731"W appears to be correct, slightly below the Mean High Water Springs mark. WGS84 6°13'36.9"W appears to be about 60 metres due east, inland. Using Memory-Map, the difference between the most westerly Mean High Water Springs mark (high tide) and most westerly Mean Low Water Springs mark (low tide) on the Corrachadh Mor headland; is approximately 9 metres further west. (On the Point of Ardnamurchan headland. Memory-Map shows a difference between the most westerly Mean High Water Springs mark and the most westerly Mean Low Water Springs mark of approximately 22 metres further west.) Again using Memory-Map. The most westerly Mean High Water Springs mark of Corrachadh Mor is approximately 23 metres further west, than the most westerly Mean Low Water Springs mark of Point of Ardnamurchan. This is interesting. However, it depends on where I judge the the most westerly points are; using Memory-Map. Furthermore, the accuracy of the Memory-Map software and Ordnance Survey mapping. The distances were calculated by using the Geoscience Australia website. 30.78 metres is from the grid references of the letter of 17 March 2004 and 42.81 metres from the letter of 28 September 2004.

Sulasgeir (talk) 13:36, 24 September 2012 (UTC)

Ordnance Survey 17 March 2004, "Land's End is (134112.1, 25364.7) (5′ 43.03 W, 50′ 4.13 N)." Ordnance Survey Coordinate transformer 134112.1, 25364.7 = ETRS89 50° 4′ 7.69486″ N, 5° 43′ 1.55270″ W. Therefore Corrachadh Mor's longitude at the latitude of Land's End is 36573.101 metres (36.573101 kilometres) or 22.72547 miles further west than Land's End's longitude. Distance calculated using the Geoscience Australia website, and therefore in the Geodetic Datum WGS84.

Sulasgeir (talk) 17:18, 20 May 2013 (UTC)

Letters 28 September 2004 and 17 March 2004: Sulasgeir (talk) 15:55, 3 July 2013 (UTC)