Usuario:Mcapdevila/Rhumbline-merge
Merging Proposal to Portolan Chart[editar]
It would be incorrect to merge it to to Portolan Chart for there are plenty of mapamundi that use the Rhumbline network and by no means can be considered portolan charts (they do not have any PORT-harbour on them)
--Mcapdevila (talk) 21:34, 20 October 2015 (UTC)
- This can be removed. The discussion is at Talk:Portolan chart#Merger proposal. RockMagnetist(talk) 21:48, 20 October 2015 (UTC)
Copy of Merger proposal from Rhumbline[editar]
The article Rhumbline network is mainly about portolan charts, and is rendered doubly redundant by the article Rhumb line. I propose merging its content into this article. RockMagnetist(talk) 15:59, 20 October 2015 (UTC)
- It would be incorrect to merge Rhumbline network to Portolan Chart for there are plenty of mapamundi that use the Rhumbline network and by no means can be considered portolan charts ('they do not have any PORT-harbour on them')
--Mcapdevila (talk) 21:34, 20 October 2015 (UTC)
- Would it make sense to merge it with Rhumb line, then? RockMagnetist(talk) 21:50, 20 October 2015 (UTC)
- The assertion:"Rhumbline network is rendered doubly redundant by the article Rhumb line" it's not exact.. for its primitive name was "winds network" (from italian griglia dei venti) not related at all to the English concept developed in the rhumbline article they are just false friends using the same name (600 years away from each other).. I've added it to the article to avoid any misinterpretation..--Mcapdevila (talk) 22:28, 20 October 2015 (UTC)
- I'm not convinced. In Rhumbline network, I don't see any definition that would distinguish the lines from rhumb lines.The existence of an Italian term for it is no evidence that it is really different. In Portolan chart, rhumb lines represent constant compass directions. The definition in Rhumb line is equivalent, but more general as it applies to ocean crossings as well. RockMagnetist(talk) 00:44, 21 October 2015 (UTC)
- Then we should have to merge it with both rhumb line and orthodrome.. In the Med, for the portolan, your assertion would be true, but not in the planispheres (those which do not follow the mercator projection).. If one "submerges" its eyes into the catalan or italian maps of that time and studies them (I've been doing it for the last 55 years, my father made me a present of a facsimil of Cresques planisphere in my 15th aniversary 23-10-1945).. onewould be able to read the names of those lines which were taken from winds: Tramontana, levante, ponente, mezzogiorno, greco, sirocco, lebegio.. tat the same time one could investigate that they follow both, rhumb line and orthodrome, or neither of them, due to the imprecision of the map projection of that time, being the rhumb line only almost true in the Mediterranean portolan charts and a complete mess (for its in-exactitude) in the Texeira planisfere (and the others mentioned before)
- Today, after the mercator projection, we have two concepts clearly distinct loxodromic navigation and orthodromic navigation and the thousands of english speaking sailors (as my coleague and sailing friend Rodney Pattisson), map makers, etc.. they know perfectly that fact..--Mcapdevila (talk) 08:31, 21 October 2015 (UTC)
- I'm impressed by your knowledge of maps, and would like to be sure that we come up with a solution that you agree is correct. I think the main issue is, what is a rhumb line? If that is settled, then a rhumbline network is just a network of rhumbs, and not really a separate concept. We need to answer this question for the English language; maybe the meanings are different in Italian, but that's not relevant here. For convenience, I am going to quote the Oxford English Dictionary meaning. Rhumb line is equivalent to the first sense of rhumb, which is:
1 a. The line or course followed by a ship or other vessel sailing in a fixed direction. Also: an imaginary line on the earth's surface intersecting all meridians at the same angle and used as the standard method of plotting a ship's course on a chart
- (I'm not sure what a "fixed direction" means if it's not based on geographic or magnetic meridians.) RockMagnetist(talk) 17:29, 21 October 2015 (UTC)
- I don't think the distinction between loxodromic and orthodromic navigation is relevant here; even in modern navigation manuals, a rhumb line is clearly identified with constant bearing, never with great circles. See, for example, the Admiralty Manual of Navigation and The Flight Navigator Handbook. Similarly, some directions may have been associated with winds, but wind directions aren't very reliable. Correct me if I'm wrong, but I would guess that in the Cresques planisphere, the directions for the lines were chosen by some other method, after which the wind labels were added. RockMagnetist(talk) 17:29, 21 October 2015 (UTC)
- There is some logic in RockMagnetist's reasoning. However he departs from the false assumption that only portolan charts depict rose-wind systems (this is a better way of calling it because those lines are not true loxodromes). The fact is those systens of lines (rhumbs) irradiating from certain points of the charts were adopted in other cartographic models, such as the latitude chart of the Atlantic (from about 1500 on) and even the Mercator chart (from 1569 on). I agree that the distinction between loxodromic and orthodromic navigation is not relevant here. Only in 1537, in a treatise of the mathematician Pedro Nunes (Treatise in defense of the nautical chart), was such distinction made for the first time. Anyway, orthodromic navigation was (and is) seldom used by mariners (I know, I am a navy officer). I hope these considerations help. Alvesgaspar (talk) 20:42, 21 October 2015 (UTC)
- At the end some clever words from Alvesgaspar that I think should clarify the case: "..rose-wind systems (this is a better way of calling it because those lines are not true loxodromes)..".. I have created loxodromic navigation and orthodromic navigation to explain that it has been with the mercator projection (1569), that a rhumb line could be represented by a straight line.. rose-wind lines from the portolans (1275).. are straight lines.. therefore -for Reductio ad absurdum- they can't be loxodromic (today's rhumblines).. otherwise the mercator projection would have been invented in 1275.. They are false friends (inside english language) that lead RockMagnetist to the actual confusion.. By the way... it would be of interest reading the doctoral paper of Mr Hurtado where he explains the portolan projection as the addition of multiple azimuthal projections with multiple centers -like today's Google maps- (the best explanation-theory I've found in 55 years)... but this would be like opening Pandora's box..--Mcapdevila (talk) 06:36, 22 October 2015 (UTC)