PIRI REIS, HIS WORKS FROM 1513 TO 1528 CARTOGRAPHER AND MATHEMATICIANINTRODUCTION
This short text is occasioned by the receipt of an email from a Professor of Geography who asked for comments on the 1513 chart and the Antarctic theory.
Some 45 years ago I read books which purported to explain the coastlines shown on the 1513 fragment and carried out a quick diagnostic on the chart fragment which to my mind clearly debunked the wild theories written. I merely tried to use the scale bar to evaluate what was drawn and produced two sketches which were folded into one of the books. As the years progressed I read other papers with some alarm but took no action as it appeared to me researchers were not applying the basic tools given by the chart to “solve” the apparent mysteries. I thought all that was written was from a desire to believe rather than the application of proper research. Later texts indicate some common sense was available.
Thus this text is a short resume of my findings setting down facts not wild ideas.
THE 1513 CHART; BASIC ANALYSIS
The chart is drawn on European Roe Deer skin which is one of the smallest of the Deer family having a body length varying from 95 to 130 cms and a shoulder height of 65/75 cms. Thus the probable maximum skin available for use as a chart base is no more than 90 cms girth and 110 cms length. The Roe Deer has a red coat and would not be mistaken for a Fallow Deer which is larger and has a chestnut coat with white mottling. My text “Leather Vellum Parchment” clearly indicates what would be seen when a skin is prepared for usage.
The fragment extant is c90 x 60 cms with the obvious overlap joint to the north and is thus in all probability the full girth of the skin. It has thus been reduced in its length or longitude from a maximum of c110 cms, but, to establish the charts original size we must interrogate the Wind Rose as drawn.
ChPIR/1/D001
There is obviously a horizontal Wind Rose centre line passing through “Hispaniola”, a Ship and the African Continent south of the Canary Isles. Using the scale bars appended which are shown as having five sections per division and knowing, as Piri Reis informs us, a Portolan Chart was utilised to construct this 1513 Chart, by testing the scale bar against the West Coast of Iberia, 37N to 43N we can establish a latitudinal scale. That can be subsequently tested on the West Coast of Africa and to establish a ratio to longitude. The measurement produced 75 scale bar units for the six degrees of latitude, 37N to 43N and thus we can state they are Miliaria of 1.233 KM per unit. Apply this measurement scale bar to the Wind Rose and immediately the construct appears as a mathematical concept.
THE WIND ROSE AS A DETERMINANT
ChPIR/1/D002
The Wind Rose as my texts ChWR/1 and ChWR/2 clearly prove is based upon 4 ratio measures, 35/30/20/7 and normally they are drawn as a graticule of 35/30/27 units. Using the scale bar the Wind Rose subdivisions are 35 x 50; 30 x 50 and 27 x 50 or 92 x 50 overall. But given that there is a latitudinal degree measurement within the chart of 75 units per degree the Wind Rose is a natural latitudinal scale of 23.330 x 75; 200 x 75 and 180 x 75 which means that the Wind Rose is 61.33 degrees per quadrant and for full square 122.66 degrees latitude. But note that the first subdivision is 23.33 degrees and thus it represents the TROPIC which varied according to charts from 23.33 to 23.5 to 24 degrees from the equator. Therefore the centre line is the EQUATOR, the southern line is 38S and the northern line is thus 84.66 degrees with the Arctic Circle shown at 66.66 degrees. The diagram is set out from the Wind Rose and indicates the original fragment set into the overall frame of the Wind Rose. The latitudes are thus from Zero degrees, 23.330; 46.660; 66.660 and 84.66 degrees north with the putative skin edge allowing for the North Pole at 90N. Thus we have the Equator, Tropic of Cancer and Arctic Circle delineated in the north, and, south of the Equator we have lines at 20S and 38S which allows for encompassing the Cape of Good Hope at 35S/20E.
But of course longitudinally it is a very different set of figures and we can clearly determine that they are based upon the 5:4 ratio of 36N which provides for a 75 x 60 Miliaria graticule. Measure from Cape Verde (17W) to “Sta Roka” or Cap Sao Roque at 35W/5S and the 18 longitudinal degrees are all 60 Miliaria. Hence the longitude of the Wind Rose (not the chart) is 122.22 x 5/4 = 153.325 degrees.
The Wind Rose itself is four sections and overall is 9200 scale bar units square.
We now have sufficient information to evaluate the whole chart as a symmetrical construct as the diagram illustrates. But it clearly indicates that three Roe Deer skins would be required to form the whole chart using two skins side by side and the third cut in half for the northern sections.
I will make an observation here that the photograph of the chart fragment does not appear to indicate that a northern section was glued there-on. However the Wind Rose lines clearly indicate a continuation northerly and it could be that the top section was glued via a rear strip and not the overlap. But that is just a comment.
THE OVERALL ORIGINAL CHART
ChPIR/1/D003 & D004
As will be shown in following sections, Piri Reis within Kitab-i Bahriye where a “Planisphere” is drawn it clearly indicates the probable origination of the form from this 1513 chart. Using that Planisphere we can thus evaluate the 1513 chart with a putative scheme.
The two diagram sheets which can be joined to form a putative overall chart incorporate the 1513 fragment and the Planisphere, and from this it can be seen that the Equatorial alignment is excellent and the Tropics are clearly very similar. The problems of the West Indies and South America are dealt with later
THE PORTOLAN CHART; KITAB-I BAHRIYE
ChPIR/1/D005
Bound into a book it requires to be carefully aligned to produce the correct overall format. It contains a schedule graticule which is not filled (at least the copy I am using is not) and I suspect it may have been a list of latitudes or similar. But a simple utilisation of the scale bar enables the Wind Rose design to be exposed as another tour de force by Piri Reis and scaling the latitudinal divisions with a calculated centre line at 43.66 degrees north the chart is 37 degrees latitude and 59 degrees longitude with correct 90 miliaria latitudes.
It is thus a typical Portolan Chart, copied no doubt from those he obtained but drawn with the flair for presentation Piri Reis has shown elsewhere. The mathematical knowledge of Piri Reis is again to the fore where the Wind Rose Graticule is based upon simple whole degrees of both latitude and longitude, but set down very accurately as the diagram clearly illustrates.
ChPIR/1/D006
THE DOUBLE HEMISPHERE WORLD MAP; KITAB-I BAHRIYE
ChPIR/1/D007
This very small scale chart portrays the knowledge of 1525 with the Far East starting to be known sufficiently well for cartographers to include the information with confidence. Would that it was drawn to a large scale and the areas shown, but not really understood, then evaluated. A simple evaluation of its construct shows that it is based upon the centre-lines 10 degree divisions and for its small scale is highly accurate as is shown by the longitudinal scale markers and the latitudinal curves of the 36N and 35S lines for the centre of the Mediterranean Sea and the Cape of Good Hope. Note how the geographical form is curved to suit the circular format of the hemispheres. It is a rather good small scale chart for all that.
THE OVAL PLANISPHERE; KITAB-I BAHRIYE
The beautifully drawn world chart has hidden features which indicate it is a “trompe-l’oeil”. Firstly, if it is considered as a map then it is 180 x 360 degrees all of which are identical and hence it is a square map or chart. Here there is no curvature of the geographical form to follow the longitudinal curves and it is thus merely a plain square chart onto which semi-circles have been appended. Study the diagrams and it is shown that the longitudinal lines, curves, which should meet at the Poles are in fact are a mixture of perfect semi-circles as the end frame and with graded curves from the 90 degree positions to the centre longitude. Also they are unequally spaced across the chart as indicated by the correction line marks.
ChPIR/1/D008
ChPIR/1/D009
But look beyond the lines of latitude and longitude and there exists the plain chart which is actually a basic cylindrical projection with lines slightly curtailed in the north by the oval frame, but if all lines are extended as shown the cylinder is complete. Thus my text “CgLdV/1, Leonardo da Vinci and Globe Gores” in which I believe we see the first cylindrical projection drawn 1507 may well have been a forerunner of this mathematical Piri Reis map.
It obviously incorporates the great southern continent beloved by the philosophers of old to balance the world having a very large northern continent, but overall it is not as simple as the Double Hemispherical chart previously discussed. Had the great southern continent been omitted it would surely be a first rate chart of the world.
ChPIR/1/D010
ChPIR/1/D011
One of a few double page large scale charts to be found in Kitab-i Bahriye it exemplifies the skill of Piri Reis in colour presentation. It is slightly awry in its positioning of the geographical features as can be observed from the overlay diagram with its geographical graticule. However the graticule does indicate the adherence to the 5:4 ratio when the grid is given putative distance measures. It is drawn with the islands closely to scale and would have been so very useful had a scale bar been appended to evaluate not only this chart but all others as well.
ChPIR/1/D012
ChPIR/1/D013
PIRI REIS SECOND WORLD MAP (?); 1528, FRAGMENT OF 68 X 69 CMS
ChPIR/1/D014
The chart fragment illustrates the geographical area of the West Indies, Newfoundland and the Azores. From the scale bars and the positioning of the Islands it is possible to evaluate the intent of Piri Reis and the total chart.
ChPIR/1/D015
The Tropic of Cancer, although drawn close to 20N latitude geographically is a good guidance alignment. From Trinidad to the west of Cuba is geographically from 60W to 85W, that is 25 degrees longitude and from this it is possible to evaluate the scale as each five degrees of longitude is acceptable as equal and thus the latitudes can be calculated from these measurements. The Wind Rose from those figures is 44 degrees longitude and via the 5:4 ratio the latitude of the Wind Rose is thus 55 degrees Therefore as the longitude of each Wind Rose segment is known the equivalent latitudinal segment can be evaluated and using the Tropic of Cancer as 23.33 degrees (from Piri Reis own works) the resulting grid can be given its appropriate scale. The results are clearly shown on the diagram which positions the Azores at 38N and Labrador/Newfoundland at 54N (geographically 46.75 to 60N) with the Greenland section correct at 60N.
Consequently the Wind Rose and putative single square chart can be evaluated. But if it is a World Chart (?) this would mean in all probability it would require a double Wind Rose and thus possibly had the following extra length. We have extra from 11E to 99E (ie, 77W-11E-99E) and thus the chart could be from 92W to 114E.
However a second alternative is possible in that the basic square chart derived from the fragment is actually duplicated with the extra section set centrally and then the chart would be from 92W to 134E, which is a more likely longitude if it is a World Map as the Far East was known by 1528.
ChPIR/1/D016
But this chart requires to be evaluated by actual physical measurements as is done later with surprising results which are a step too far.
A PUTATIVE BUT SENSIBLE EVALUATION OF THE TWO AREAS OF CONTENTION OF THE CHART FRAGMENT DATED 1513
ChPIR/1/D017
It is obvious from the chart that Piri Reis has double copied certain islands etc in the West Indies section of the fragment. But as previous texts seek to explain the chart using the toponyms Piri Reis has appended, when it is obvious he did not know what he was in fact copying, had not visited the area to understand the geography and thus it is all an educated guess on his part, makes me believe that accepting the toponyms to position some the geography is perhaps a gross error of judgment.
Study the fragment and note that from Trinidad there is an excellent representation of the Windward and Leeward Islands stretching north to Puerto Rico and then westerly to Hispaniola. These are drawn rather well as is to be expected in 1513 and represent the geographical situation. Thus if the 1513 chart is cut as the diagram illustrates and rotated through 90 degrees to the west, the Golfo de Venezuela (marked A) is drawn and to its west is the spurious “Cuba” as noted by Piri Reis. In fact the shape of the coast from Punta Gallinas to Barranquilla where Piri Reis has inserted his three Towers is quite acceptable. It is therefore apparent to me that Piri Reis deliberately twisted the coastline northwards thus ensuring all of the information he had obtained, but neither really knew nor fully understood, was utilised.
That comment is made from these facts; the Arab script is written from right to left and it is the methodology of their scholars and thus if Piri Reis located first his master chart section, the Mediterranean Sea Basin area, probably the most complete area he had a chart to copy from as the Kitab-i Bahriye indicates, then working to the west or left he ran out of space on the Roe Deer Skins and had no alternative but to rotate the coastline northwards to complete the knowledge he had as a chart. That premise also applies to the southern section of the coastline of South America as it appears he planned for the tip of South Africa at 35S.
ChPIR/1/D018
If we are to believe that the East coast of South America was explored to c50S by 1505 then we must ask at what date Piri Reis received the information. If it was thus after the main chart was ghosted out on the three Roe Deer Skins, then only allowing for the tip of South Africa at 35S, meant he had at least a 15 degree discrepancy in latitude and hence he has incorporated the information of the newly discovered southern lands as best possible by rotating the coastline to the east.
At no point in time can we establish when Piri Reis obtained the “latest” information and thus cannot state what or how he has actually amalgamated it into his basic chart. These are all putative ideas from the charts format on the basis that William of Oakham had the best solution.
DEBUNKING TEXTS WRITTEN WHICH ONLY SERVE TO CONFUSE
1) The southern limit of the Piri Reis 1513 chart is given by the Wind Rose as slightly south of the 38th latitude. Therefore there is no reason to contemplate the easterly land from South America as “Antarctica”. It is the coastline of South America twisted east to fit.
2) The Tropics and Equatorial line are clearly indicated by the Wind Rose graticule which is a perfect mathematical construct from the scale bar and its 50 Miliaria base divisions which transfer to the 75 miliaria latitudinal measures required.
3) Accuracy; there is very little in the fragment extant except the west coast of Iberia and Africa which is set out at 75 miliaria per degree. The longitudinal distance from Cape Verde (17W) to Cap Sao Roque (35W) scales perfectly at 60 miliaria per degree. Study the Portolan Chart and the Planisphere in Kitab-I Bahriye where as I have shown accuracy abounds.
4) The scale of the chart is 75 miliaria per degree of latitude and 60 miliaria per longitudinal degree conforming to the standard proportion obtained at 36N, the 5:4 ratio and that would have been shown on the Portolan Charts that Piri Reis utilised for his chart.
There is thus no League distance measure used on this chart.
CONCLUSION
Too many researchers have written texts regarding the Piri Reis 1513 chart from a position of preconception. Unfortunately in the 1970’s the fiction regarding historical data was subsumed by people looking for any answer to “mysteries” without proper research.
Piri Reis is an accomplished draughtsman, cartographer and mathematician, but he could only work with the data available to him at any given time. That he managed to produce the section of the 1513 chart we have to study is indicative of his prowess. But, and it is a big but, extrapolating from this fragment to a full planisphere chart may have exposed considerable error based upon spurious information. Thus care must be taken in the use of this fragment and its apparent “mysterious” geography.
The Kitab-I Bahriye of 1525 is however a masterpiece and lacks only scale to enable its usage in the wider world. That would enable the size of the islands to be judged against each other and an appreciation of the “world” with its vagaries known.
The 1528 so called “second World Map” is perhaps not that at all. The size of the fragment at 68 x 69cms if extrapolated to a square chart would be some 100 x 140cms and thus as I believe it to be a Portolan Chart of the Mediterranean Sea Basin.
If it is a double Wind Rose it is probably 100 x 220cms and if a double Wind Rose with spacer areas it would be some 100 x 280cms.This would rival the largest European Charts and as it is drawn to a large scale it would require a large amount of detail to be drawn to fill the chart area which was just not available in 1528. Unless, as with other charts, it was filled with make believe lands.
Thus I believe the 1528 chart is not a “World Chart” but a “Portolan Chart.”
Thus by studying all of the extant works of Piri Reis and not focusing upon one chart we can establish a raison d’etre for what is shown and note the corrections made by Piri Reis as time progressed. Bear in mind also the time scale required to drawn these charts, even allowing for another to write the scripts, it is a long period for each chart and the collection of the skins and their preparation would be required well in advance. Thus there is also the planning aspect of these works to add to the expertise of Piri Reis, and that should not be forgotten as it is the basis of preparation for all cartographers.