Arab Trans-Oceanic Navigation Before Columbus

  • 2 Replies

17 November

  • Flat Earth Believer
  • 1317
Arab Trans-Oceanic Navigation Before Columbus
« on: June 09, 2011, 05:41:50 AM »
'The Pre-Columbian Discovery of the American Continent By Muslim Seafarers'
By Professor Fuat Sezgin

This lecture by Turkish science professor Fuat Sezgin is the best analysis of pre-Columbian transoceanic travel that I have ever read.
The occasion is the refutation of the popular and highly erroneous book '1421:  The Year China Discovered America' by Gavin Menzies.
In accordance with the critical examination of evidence throughout this paper, this thesis appears on pages 37 and 38:

"There is historic evidence that muslims resp. Arabs tried repeatedly to travel westward across the Ocean from the first half of the 10th century on, at first from Portuguese and later from West African harbours.  The aim was quite often defined as reaching "the opposite End of the Ocean."  Based on our knowledge of the cartographic achievements and the remarkably advanced navigation in the Arab/Islamic culture area along with the cartographic materials mostly surviving in European copies, I arrive at the considered opinion that it must have been Muslim navigators who had not only reached the new oceanic continent certainly by the beginning of the 15th century but even started to survey it.  The passage from Fra Mauro already quoted above in which he states (in the year 1457) that in 1420 a ship coming from the Indian Ocean had passed the Cape of Good Hope and travelled via the Cape Verde islands apparently on course to the "Isles of Men and Women" in the Caribbean and back to the Cape of Good Hope, implies at least that this route was already known in 1420 and that reports about these activities had reached Venice by 1457"

Turkish Professor Fuat Sezgin is the foremost scholar of Islamic science in the world.  Earning a Ph.D. from Istanbul University in 1961, Fuat Sezgin was dismissed from his job after the 1960 coup of Turkey's government by fascist Grey Wolves founder Alpaslan Turkes and thus resettled in Germany.  In 1982, Sezgin established the 'Institute of the History of the Arab Islamic Sciences' which now houses the most comprehensive collection of texts on the history of Arabic-Islamic science in the world.  Sezgin has founded museums of many hundreds of replicas of historical scientific instruments, tools and maps, mostly belonging to the Golden Age of Islamic science in Germany and Istanbul.  His 13-volume work 'Geschichte des Arabischen Schrifttums' (1967-2000) is the cornerstone reference on the history of science and technology in the Islamic world.
« Last Edit: May 21, 2012, 09:51:14 PM by 17 November »


17 November

  • Flat Earth Believer
  • 1317
Re: Pre-Columbian Trans-Oceanic Navigation
« Reply #1 on: July 20, 2011, 04:53:29 PM »
1502 World Map of Alberto Cantino

Quote from: Alberto Cantino World Map Wikipedia Article
The Cantino planisphere (or Cantino World Map) is the earliest surviving map showing Portuguese Discoveries in the east and west. It is named after Alberto Cantino, an agent for the Duke of Ferrara, who successfully smuggled it from Portugal to Italy in 1502. The map is particularly notable for portraying a fragmentary record of the Brazilian coast, discovered in 1500 by the Portuguese explorer Pedro Álvares Cabral, and for depicting the African coast of the Atlantic and Indian Oceans with a remarkable accuracy and detail.

In Refuting Gavin Menzies book '1421: The Year China Discovered The World' Turkish Science Professor and historian Fuat Sezgin writes in 'The Pre-Columbian Discovery of the American Continent by Muslim Seafarers':

"On his quest for support of his theories Menzies became aware of the surprisingly modern delineation of Africa, especially of its east coast, on the map charted assumedly in 1502 by Cantino. For Menzies this map “where the coast of East Africa is depicted with such accuracy that it appears to have been drawn with the aid of satellite navigation” (Note 31) too bears witness to “Chinese expertise”, for “who else but the Chinese could have drawn this astounding chart?” After explaining why the Portuguese can be ruled out as possible originators of the map, he goes on wondering “if Arab navigators could have been the original cartographers.”  Menzies’ unconsidered answer is no, because he “found not one detailed Arabic chart of the east coast of Africa in Youssuf Kamal’s Monumenta Cartographica. Although the Arabs understood how to calculate longitude by lunar eclipse, they never mastered how to measure time with the necessary accuracy, something that the Chinese achieved”.   

  It is impossible to deal at length with all the statements, claims and assumptions Menzies abounds with, yet I would like to concede one point to him,
viz. that the Portuguese cannot possibly have been the originators of the Cantino map. Not only did they lack proper methods for the determination of longitudes as well as accurate chronometry, but especially because the charting of such a stunningly realistic map of Africa must have been a far more time-consuming project than Menzies seems to realise, a mistake that, incidentally, pervades his whole line of argumentation.

For centuries the Indian Ocean has effectively been like a huge lake enclosed by the Arabic-Islamic culture area.  In addition to the familiar methods for the determination of longitudes
on land, the navigators in the Indian Ocean developed a highly sophisticated method of measuring distances on the open sea parallel or oblique to the meridian as well as parallel to the equator. The last case is equivalent to a determination of longitude. It was a true triangulation, suited for reliable and accurate measurements of trans-oceanic distances on the open sea.
Data found in extant Arabic and Turkish navigation manuals from the 9th/15th and 10th/16th centuries confirm that ample and adequate measurements of the Indian Ocean were taken to the extent that a comprehensive cartographic representation was rendered feasible. Hence Wilhelm Tomaschek was able to reconstruct very fine partial maps according to those data available to him in the year 1897, i.e. at a time when the most important Arabic nautical books had not even been rediscovered."

Footnote 31:  '1421: The Year China Discovered The World' By Gavin Menzies, page 375f.
Interestingly, this passage has been omitted in the second English edition (page 377).




17 November

  • Flat Earth Believer
  • 1317
Re: Arab Trans-Oceanic Navigation Before Columbus
« Reply #2 on: May 21, 2012, 09:55:10 PM »
I think the exactitude of the Piri Reis map and a select few other highly accurate maps of the immediate post-Columbus period are based on Islamic navigation of the oceans which preceeded Columbus.

I finally acquired a copy of Fuat Sezgin's expensive book summarizing the best of fifty years of his articles on Islamic astronomy, navigation, and geography, but I have not yet had time to read it.
« Last Edit: May 21, 2012, 10:11:31 PM by 17 November »