Now comprising 10 sheets; the ‘Raxon de Marteloio’, ‘seven charts’, a ‘circular World map’ and a ‘Ptolemaic world map’, they have now been removed from a binding which stitched through their centre fold and presented in a boxed edition folio. It was produced in 1993 as a special publication of 1500 exemplars, (this authors is number 1148), and has a text by Professor Piero Falchetta of the Biblioteca Marciana,Venice, which holds the ‘Atlante Nautico’ and he describes the content (in Italian) but does not attempt to analyze the diagrams or charts cartographically. It is a historian’s narrow view of the ‘Atlante Nautico’.

This paper delves into the construction and draughtsmanship required for the charts, their geometry and trigonometry as well as explaining the ‘Raxon de Marteloio’ principles as set down by Andreas Biancho which have hitherto been basically mis-represented and not forensically examined to exhibit the simple facts. There is also a discussion apropos the supposed Ptolemaic map of possibly indifferent authorship and the problems there-of.

14 A4 pages and 29 full colour diagram maps

The text by R J Pujades i Bataller referring to the winds and technical items within Les Cartes Portolanes is contained within pages 473-481 and 513-514. Here-in R J Pujades sets down his research and reasoning for the origination of the physical work entailed in producing a Portolan chart, the process of copying and the possible scales used as a reason for the charts observed sizes. He clearly focuses upon the wind diagrams and its draughtsmanship, but, it can be clearly shown that his reasoning is based upon a false premise. The background graticule can be shown to be the arbiter of the Portolan chart with the copying method to obtain a number of similar charts merely the use of templates. The background graticule assists in the primary positioning of the map, and certainly provides the chart scale.

20 A4 pages and 20 full colour diagram maps

The 1403AD Portolan Chart of Francesco Beccari has been studied in a historical and a technical paper. Commented upon as unique for its latitudinal scale and what may be considered a rather self serving, apologetic text for past chart failures, it requires researching.
Ignoring the previous texts for the main analysis of the 1403AD chart, the actual evidence paints a different picture. Thus it is then possible to show by comparison to those texts the technical detail that should have been assessed and thus a more correct conclusion arrived at.
Finally, the 1435AD Portolan Chart of Battista Beccari is also analysed with the obvious necessity of a comparison to the 1403AD Portolan Chart.

12 A4 pages and 20 full colour diagram maps

Within the pages of Les Cartes Portolanes, R J Pujades argues that the background graticule of the Portolan charts, although drawn on each chart, is not ipso facto part of the construction. On page 513/514 entitled “The Keys to success; the wind network and the decimal based scale”, he concludes,

“Does this mean that the wind network played no role in the actual construction of the first graphic designs reproduced in nautical charts? I do not believe so, since it is one thing to deny the usefulness of the wind network as a basic pattern for obtaining new copies from a previously established model, but quite another to extend this conclusion to the initial moments of the configuration of the first models”.

This is shown to be based upon a false premise, from non-researched extant data which is adequately shown upon the Portolan Charts themselves as this text will indicate.

12 A4 pages and 14 full colour diagram maps

The wind rose graticule has been shown to be a simple geometric construct based upon the side length ratios of a triangle for angular deviation. The ratio of the squares when drawn is 35: 30: 20: 7 TRU’s (trignometrical ratio units). But what if the charts size and chosen scale does not allow for an easy conversion of the ratio numbers to scale measures? This text is an appendix for the original ChWr/1; Wind Rose Construction text.

The earliest Portolan Charts numbered C1 to C4 in “Les Cartes Portolanes” and the Lucca Chart are compared to each other and a Geographical Mercator chart. Thus the similarities of draughtsmanship can be observed and as only one set of Portolan Charts by P Vesconte (C3+Atlas) are signed the opportunity of possibly attributing anonymous charts becomes viable as the outlines coincide, in one instance spectacularly.

9 A4 pages and 26 (33)full colour diagram maps

The conclusion to my text ChCs/1 is that the Riccardiana ms 3827 chart was in all probability an original Pietro Vesconte Chart and dated from 1300/1310AD. Via my draughtsmanship/cartographical evaluation it was shown to be the template for the later charts and atlas of Pietro Vesconte. Now continuing the comparative study with five more charts as noted below, the Riccardiana ms 3827 chart would appear to be the template, or its copy or predecessor, the template for other known and unattributed charts of the period. There are minor deviations in the construction of charts discussed and perhaps following this evaluation a re-ordering of some in the L.C.P. sequencing may be found necessary.

There are 7 A4 text pages and 18 (32) A4 diagrams

The atelier of Cresques Abraham (1325-1387) was undoubtedly a continuation of the atelier of Angelino Dulceto (!name!), who probably arrived in Majorca late 1320’s, having learnt his cartographic trade in Genoa. He was possibly still producing charts in the early 1340’s, as Chart C9 (London, Add.MS 25691) is dated to that period, although some scholars consider it may precede the 1325, C7 Chart. My ChCs/2 text also details this point as a possibility. However the change of date does not preclude the atelier continuing to the 1340’s and being the Cresque base, as the Cresque Chart is undoubtedly a copy of the Dulceto (!) charts. Therefore it is possible to opine that there is a linkage between the two ateliers.
The Cresques chart does however have two unusual features drawn thereon, one is quite unique, the second a copy feature, which are discussed in detail within this text analysis of the chart. It is then compared to the Dulceto (!) charts and other charts following the system developed for the ChCs/1 and ChCs/2 texts.

The text is 7 A4 pages and 11 (16) A4 diagrams.

The Portolan Charts that are available for testing as practical navigation aids are mostly highly decorated “library” charts, which although a visual feast are so complicated in their presentation as to be unsuitable for use in a dark cabin or ships open cockpit. It has been surmised by various authors1 that those used (if they were) on board ship were the same charts but with none of the decoration to obscure the main navigation elements. But are these charts actually an aid in any presentation mode, or are they an encumbrance through the methodology required to use them on board ship. But, were they actually used on board ship?

This text analyses the simple route from Majorca to Alexandria, Egypt, using two sailing methods; that of the Portolan chart via the magnetic compass and that using the geographical wind directions and natural phenomena, the Sun and Stars for guidance. The research cannot attempt to emulate every minor course change that was necessary and must therefore be a simple discussion that considers all methods equal and that deviations on each course will cancel each other out. There is no methodology or patent formula to allow for quirks in the sailing methods of the medieval sailors given that at various times of the year the route will require a different form of sailing for the winds and tidal flow in the Mediterranean Sea. Thus for this text, the wind is constant with no tidal deviation. However one constant used is the magnetic deviation for the period of 1300AD for the whole Mediterranean Sea, 5 degrees east to 16 degrees east declination.

There are 18, A4 pages and 11, A4 Diagrams for this text.

The accuracy of Portolan charts has been shown in my previous texts, ChCs/1 and ChCs/2 where I have compared them to each other and a geographical Mercator map.
But in 1987 J T Lanman wrote “On the origin of Portolan Charts” and within chapter 8, “A proposal for the origin of Portolan charts” he wrote 6 sections (large paragraphs) and a concluding paragraph. The 6 sections are Data Base, Projection, Skewing, Purpose, Distortion and Contemporary evidence.
This text illustrates that J T Lanman was misguided in his theoretical approach, when he concluded that an accurate chart could be drawn from the data within the coastal section of the text, “Lo Conpasso de Navegare”, when it patently cannot. He also concluded there was a magnetic declination used to plot the coastal courses within the text. Then he used a square grid for his reconstruction which has been shown to be nonsensical. The graticule is rectangular and although it appears to accord to a Mercator map, that is coincidental.
That his points are spurious is amply illustrated in this analytical text. It is necessary to point out though that J T Lanman used a text with many errors for the distances and bearings, and appears not to have cross checked the distances from the Peleio route distances which are multitudinous within the text and generally very accurate.
Thus I am able to add a postscript to this analytical text which has a surprising conclusion concerning the actual possibility of drawing a map from “Lo Conpasso De Navegare”. But it is nothing to do with J T Lanman’s theoretical charts.
This text is a précis of my complete analysis of “Lo Conpasso De Navegare” carried out to investigate the possible uses for the text and its accuracy. It concentrates only on the Western Mediterranean Sea area from the Pillars to Sicily, as a means of curtailing the text.

There are 23, A4 pages and 10, A4 diagrams.

The Carta Pisane has been the subject of much speculation since it surfaced in Pisa. Is it the oldest known example of the genre of Portolan Charts, the dating is rather nebulous: was it drawn using the text of “Lo Conpasso De Navegare” (LCN): was it used at sea, thus its deleterious state: why does it appear to exhibit far more than the supposed next set of charts by Pietro Vesconte: is it merely a wishful thinking plot and not reality in the extreme areas of the chart. All of these points have been discussed ad infinitum by researchers, but the actual chart I believe has never been the subject of a forensic cartographical examination until now.
The only definite from the above list that can be quantified concerns “Lo Conpasso De Navegare” and that has been shown to be unlikely as the source of the chart using the “Starea” descriptions alone. This paper concentrates on the technical cartographical aspects of the chart, its scale, draughtsmanship and the methodology that was probably used to construct the basic outlines, but at all times uses the LCN as the basic parameter. Whether that is a correct assumption may be argued, but at least it is a basis for evidential research. The Peleio distances are shown to be the primary source of distance measure for the chart with their wind directional component. It is then shown that the actual coastline between node points gained from the Peleio distances is freehand drawn, mostly guessed, but some with real knowledge of the shape and form of the littoral.
The two wind roses are shown to be dimensioned using the same mathematics as the “Tavola De Marteloio” for the 45 degree alignment, that is 71 units, and thus the overpowering square features located in four positions on the chart are quantified.
There are correspondences and also complete differences to “Lo Conpasso De Navegare”, and thus that text does not provide for an adequate guide to the charts origins. But, the Carta Pisane is a carefully constructed chart suffering from the vagaries of poor and corrupt data producing distortion, not magnetic declination, and neither does it produce a chart usable for Pelagic Sailing because of the distortions there-in.
It is however in part well drawn and requires visual assessment over and above the first impression it unfortunately portrays by its state of preservation.

The text is 16 A4 pages and contains 25 + 2 A4 diagrams.

ABSTRACT

Having analysed “Lo Conpasso de Navegare” “Grazia Pauli” and “Liber de Existencia Riveriarum” texts to produce my text ChLCN/1, and then compared it to “The Carta Pisane” in text ChCpS/1, I concluded that the LCN text in its “Starea” section was unfit for purpose as the basis for constructing a chart. However, the Peleio section of LCN could be the basic data with which to draw a map or chart from the matrix that could be produced there-from. Although Peleio distances correctly positioned a large number of coastal features they required evaluating to determine if they were the actual basis of the Portolan Chart construction. But of course the LCN does not include the Atlantic Sea area!
Starting with the Peleio distance/directions, all +300 of them plotted on a series of maps, I concluded that a triangle formed the basic reason for the choice of node points. The points interlinked to cross locate from many of the coastal features. In fact a considerable number of the individual Peleio distance/direction notations were very accurate such that there could be NO magnetic deviation within the text details.
There were however many obvious scribal errors both for distance and direction when evaluated against a geographical map. Most could be shown to be attributable to poor copying, scribal error, but one section is solely responsible for the apparent distortion of the charts, which has led to the belief in a magnetic deviation.
My conclusions are that an original form of LCN Peleio data was used to draw the Portolan Charts. I believe the origin is probably from the Roman Period 300BCE to 300CE: there is no magnetic deviation at all in the charts draughtsmanship: the inaccuracy of the map plot is attributable to the mistaken distance measures from Sardinia to N Africa which imparted a bias in the map plot: the measurement used on the early charts is derived from the Roman Mile of 1.47911KM as one chart actually indicates.
This text cannot itemize every single Peleio; the majority are on the diagrams within this text and in the two previous texts, but where it becomes impossible to read alignments due to the sheer complexity of lines I have chosen for clarity of presentation to use a minimal number of Peleio triangle distances and thus simple Distance/Directional information.
I am sure interested parties will be pleased to draw the data for themselves and submit results. I also suggest the diagrams are downloaded, printed and joined to form large single maps (they are marked for that purpose) which will explain the twist and its false representation as a magnetic bent. It will also show that the simplest of presentations which have been misread as possible projections are nothing more than the result of drawing from a central alignment both east and west. Thus the natural positioning of a node point from the triangles causes the supposed projection. I repeat, there is no magnetic deviation on a Portolan chart!!

This text is 16 A4 pages and 29A4 diagrams. (29 pages as presented)

I have already subjected the Starea section of “Lo Conpasso de Navegare” to a detailed examination in text ChLCN/1, and followed it with a research paper concerning the Carte Pisane, text ChCPS/1, and then a major investigation of the Peleio section of LCN which illustrated in text ChCPC/1 how the basic forma for a chart could be constructed from the Peleio data and negated the idea of any magnetic interference in the charts construction.
This text uses three more charts, Cortona, Vesconte 1311 and Dulceto 1330 to investigate the continuation of the usage of an “LCN” text and compares the results to the Riccardiana MS3827 chart used as a reference point in the ChCPC/1 text.
The findings are that all use a version of the “LCN” text as the distance measures clearly indicate, but their draughtsmen or cartographers are somewhat different in their approach to the extant data c1300AD, which indicates several varying content copies of “LCN” then extant.
The Cortona chart is surprisingly accurate; it has hidden attributes. The Vesconte 1311 chart, although only of the eastern Mediterranean Sea basin is shown generally to accord with the “LCN” data, but it has been drawn from the east and thus shows a greater distortion derived from the spurious “LCN” data. The Dulceto 1330 chart appears to apply original “LCN” data for its construction and is the closest to it, hinting at a loss of early knowledge and thus the errors in “LCN” and a copyist approach to it.
The conclusions are as already posited in previous texts; the use of one or more copies of “LCN”; no magnetic deviation; obvious access to far greater detailed data than is now extant.
Included is the text ChEPC/1, an essay regarding the timescale for the original chart.

The text is 14, A4 pages and there are 27, A4 diagrams.

Within previous texts, ChLCN/1, ChCPC/1 and ChMAT/1 it has been shown that scribal errors within the LCN texts in the area south of Sardinia led draughtsmen constructing Portolan Charts inadvertently to slew to the northeast the eastern section of the Mediterranean Sea. I have already utilized charts C2, Cortona; C3, Vesconte 1311; C7, Dulceto 1330 and C8, Riccardiana ms3827 within text ChMAT/1 and thus in this text utilize 10 further charts solely for their drawn area south of Sardinia to compare their usage of an LCN text. The dates vary from 1339 to 1464 and are from C9 to C65 in LCP.
The Starea Peleio abstracted from LCN numbers 73 routes of over 100 millara and is used to cross-locate ports in both the western and eastern Mediterranean Sea. The 10 charts are presented with their scale bars to illustrate the variation but mainly the continued use of an LCN text. Thus the slewing of each chart can be shown via the distance measures used, which vary as is discussed briefly for each chart, but, the obvious agreement between them indicates that the information they are drawn from is the same “Alpha Map” base, and “Alpha LCN” text, which has been mis-copied in certain sections.
In my short essay text ChEPC/1, I opined that the Peleio section of LCN was probably taken from the “Alpha Map” as they are impractical to observe as sailing direction/distance measures at sea. I then constructed a scenario, purely speculative, which indicated that the original Portolan Chart was much earlier than 1000AD and developed from a Roman Map and itinerary text. The theme of the maps usage and ancestry is continued in this text regarding the possibility of the Starea Peleio section being driven by the necessity, firstly of the routes to be used by the new maritime cities, and then of sailing for the Crusades which provided an impetus to increase, diversify and rename ports to suit the new age and the explosion in sailing. But many quirks are included on these charts to fool us.
Thus having completed a review of LCN and the major charts of LCP, C1 to C64 and confirmed the obvious fact that by using LCN Peleio distance directions, which all charts can be shown to agree with, there is no magnetic deviation involved, just the slewing caused by the miscopying of the LCN data, Roman Numerals for south of Sardinia, it became necessary to subject the two texts used by many researchers as the basis of the Portolan Chart storyline. I refer to firstly HOC/1/chapter19 text, particularly pages 380 to 386 which deal with the subject matter of my papers and then LCP (English section) pages 510 and 511(part) which are the similar subject matter. Pages 511 & 512 are dealt with in a following text, ChCOR/1.

The text is 18, A4 pages and contains 20, A4 diagrams.

The Cortona Chart is often linked with the Carta Pisane (LCP, C1) because of the perceived similarity of presentation, its draughtsmanship and the coastlines. In my text ChCPS/1, The Carta Pisane, I fully analysed that chart’s construction and its basic internal knowledge. This text analyses the Cortona Chart in a similar manner and juxtaposes “LCP” pages 511/512 text with my findings. The resultant research illustrates that there were a multitude of “LCN” type texts used throughout the first period of the “Library Style” Portolan Charts, following the end of what must have been a massive flotilla of ships virtually constantly at sea to service the Crusades and trade that went with them, but no doubt using smaller and easily handled maps and complementary texts, Portolani + Chart.
This text starts with the Black Sea area on the chart, discusses the separate scale utilised and then the textual data available which is not apparent upon the chart. A section of the text has already been published in ChMAT/1, and is here-in appended, un- revised but very necessary to complete the research which follows the prime discussion of the Black Sea area. I have also indicated the “distortion” positions within the chart which not only make it accurate in a serendipitous manner, but show its construction from an “LCN” text. Finally, the reason for the charts distortion is revealed, simple distance measure errors which combined to visually confuse previous researchers into thinking there was a magnetic element; there is not. But why the draughtsman chose to use two differing scale bars can be answered only speculatively. As an extra discussion the Black Sea is investigated in a short essay reference ChBLS/1. The same change of scale on other charts and atlases and the actual form that can be obtained from the” LCN” text is drawn, which confirms the fact that a “Alpha Chart” was available and several “LCN” texts of varying quality.
Draughtsmanship before history and you will solve a great deal more far easier!

The text is 13, A4 pages and 8 + 6 + 10, A4 diagrams (24 in total from 3 sections of text).

Many researchers have written texts which in part discuss the work of A. Dulceto, and imply the finding of magnetic declination, magnetic compass usage to plot the charts and differing projections used to draw them.
I have chosen therefore the same chart, A. Dulceto 1339 (LCP C8) held by the BNF Paris as the base data with which to counter those theories existing in the four texts to be analysed. The chart is first dissected to indicate its fundamental structure and the varying scales used from west to east, Ptolemaic Degrees, Millara, Roman Miles and Marritimo Miglio, as well as the reasons for its skewing. The link from Rome via Claudius Ptolemy to the Millara is clearly shown and thus the origins of the “Portolani” and its accompanying chart are confirmed. Any researcher who has read my previous papers will not be surprised at the findings, quite incontrovertible, as they are merely the data the chart exudes, and thus will understand why I have not written reams of text in explanation of my findings for this 1339 chart. But the intervention of the Ptolemaic degree is surprising and is resolved by the explanation of the various distance measures within a Portolan chart.
Please note that prior to the analysis of the four texts, I have inserted a short but very necessary note regarding the use of Cartometry, Formulae and Computers to analyse a Portolan Chart and thus end up with bland averaging and an incorrect analysis of the chart.
The four texts are, J A Gaspar, ePerimetron, 2008; W R Tobler, Am Geog Soc, 1966 and 2007; J E Kelley jr. Cartographica, 1995; and C Boutoura, ePerimetron, 2006.
The results of this critique are expressed quite directly and thus I would advise caution when future researchers may wish to utilize them; I consider them to be lacking.
NOTE: I am still awaiting a researcher to explain how the magnetic compass was used to plot the courses and then, how the pilot book data led to a Portolan Chart to be drawn. It has been stated again in 2015 that “owing to the navigational methods of the time, which were based on magnetic directions and estimated distances”, that research is so very necessary. Why the “Pilot Books” extant do not use magnetic data requires answering.

The text is 22, A4 pages and contains 23, A4 diagrams.

The chart is obviously an excellent example of the genre, but it is also obviously an amalgam of two schools; Claudius Ptolemy and a LC de N derived Portolan Chart. The western section from Britannia southwards through France, Iberia to N. Africa is drawn to the Ptolemaic dictum as expressed in the prologue to Book 2 of “Geographia”, a simple proportion and rectangular graticule. But this only applies from 9W to 3E where the L C de N format then becomes apparent and the usual errors around 9E longitude skew the chart to fool some researchers into the magnetic declination school of thought. However the main problem can be observed at Bugea (Bejaia) on the N. African coast where the distortion is so apparent.
The eastern Mediterranean Sea is drawn quite accurately but expanded to agree with the L C de N Black Sea over length such that the chart is in proportion at this point.
The chart is an exceptionally well presented Portolan Chart which indicates a growing knowledge of the mathematics involved and the greater accuracy of measurement. Thus the cartographical draughtsman can experiment with the latest (although 100 years earlier) ideas as promulgated by Claudius Ptolemy in the then translated “Geographia.” But it should be borne in mind that the whole genre of Portolan Charts has always in its background had the Roman measurements and Ptolemaic proportion within the makeup of the chart. However, still after +200 years it is evident that the “Portolani” texts are obviously still being used.
Unfortunately, the Butterfly did flap its wings to cause enough Chaos in the finished chart to be noticeable, which is actually a sad occurrence for a thing of some beauty.
I have chosen to juxtapose this chart with a short text regarding two charts, Jorge de Aguiar, 1492, and Pedro Reinal, 1504, which show the partial development of the Iberian Peninsula as a rectangular graticule. The Pedro Reinal chart has the fully formed latitude scale in a similar position to the Jacobus Russus chart and thus they can be compared. This text was originally indexed as ChMES/1 and has 7, A4 pages and 6, A4 diagrams.
This text contains 6, A4 pages and 16, A4 diagrams which all interlink in their series.

Totally the text is 13 A4 pages and there are 22 A4 diagrams.

ABSTRACT

The exploration of West Africa from the Strait of Gibraltar to the Gulf of Guinea is a story of two or three parts. Firstly we have the recorded voyages pre our common era, and then apparently nothing south of the Canary isles until the Portuguese explorers ventured forth in the 15th century. Thus the second part may be described as the scramble by Portugal and Spain to land grab as much as possible. This caused friction between the two nations and was eventually solved (!) with the agreement reached at Tordesillas in 1494 (among others) and thus we have the letters of 1495 endeavouring to explain it all cartographically.
But all of that ignores the large Arab presence, their knowledge of the coastline and the fact that it was transmitted to N. Africa and thus the Iberian Peninsula in the 10th to 13th centuries. Finding the information however has proven nearly impossible, hence the following methodology, as even the text of Al-Idrisi shines little light on the knowledge. Thus this text uses the Portolan charts/atlases as a means of illustrating the knowledge gained in by the late 14th and early 15th centuries, how it affected the presentation of the knowledge and the gradual correcting of the spurious data which so affected them.
Obviously, between the 1413 and 1436 charts the work of Claudius Ptolemy intervened and affected presentation. The letters of 1495 illustrate the confusion reigning at the time over distance measures from the ancient metrologies, and the utter disregard various countries had for each other’s measurements, even though a single measure was available. This text therefore also tackles the vexed question of the confusion between the Millara and the Roman Mile and presents a reasoned argument for the Millara origination, no not 5/6ths.

The text is 21, A4 pages and contains 26, A4 diagrams and 4 appendix pages.

The Petrus Vesconte 1311 chart has featured in several previous texts, but has never been subject to a complete internal structure evaluation. This text merely corrects that omission and illustrates the accuracy which can be found longitudinally and the obvious latitudinal faults which appear to follow through to most extant Portolan Charts of later date. Those faults are distortions and are clearly set out in various papers but will be detailed here-in to define the charts. The wind rose system is the setting out and has been adequately shown to be the arbiter of the plot via its measurements. The atlases, concentrating on the 1313 and 1318 work indicate conclusively that the typical distortion of a Portolan Chart, basically shown as being from Iberia to Italy, could have been avoided by the correct application of distance measures for Iberia and from Genoa to N. Africa and a full understanding of the measurement of a degree which varies even though the name of the unit is the same. But the problem of the scale bar being firstly a Roman Mile and then considered a Miliaria can be shown to be the main cause of the deviation of the latitudinal and longitudinal lines to enthuse historians to conclude that the distortion was a magnetic deflection, Just how wrong they could be is illustrated here-in. Various other small charts are illustrated for continuity of the works by Petrus Vesconte.
There is finally an appendix which illustrates the whole distortion scenario, how it occurred and the consequences for Portolan Charts, with after words that require to be said!

The text is 15 A4 pages and has 28 A4 diagrams.

Having studied a large number of Portolan charts, as the website clearly shows, I was struck by the lack of examination of extant Atlases in the research texts of others. Those Atlases are detailed in Les Cartes Portolanes, pages 69/70, and having just reviewed my research into the work of Petrus Vesconte (ChPV/1) and revisited his Atlases, I decided to review my research including those Atlases and others, not all of them, just the first 14.
However, I did not consider that a short text could contain a complete review of those chosen as I had carried out on the Petrus Vesconte 1313 and 1318 Atlases, but instead concentrated upon the Atlas page containing the Iberian Peninsula, the starting point for the utter confusion which can be shown to exist apropos distance measures and thus the original distortion point for Portolan charts.
As there is generally only one scale bar to each Atlas page, it is thus a simple matter to ascertain the accuracy and measures utilized to draw each sheet. Thus, when a confusion of distance measures is encountered on this one Atlas Page, emanating from a single scale bar, little more than those facts require to be investigated. It also determined that the draughtsmen were not au fait with their subject matter and thus should be considered only copy artist’s, but from what? That does not infer criticism of the artistry to produce these Atlases as they are a feast for the eyes, and illustrate exquisite draughtsmanship but a lack of real knowledge, and confirms they are copies, not original works. How many originals were copied is detailed.

The text is 11, A4 pages and contains 16, A4 diagrams (some are text based).

Having analysed the Atlases LCP A1 to A14, concerning the Iberian Peninsula and established that there was a complete lack of knowledge apropos the actual distance measures utilised and that the unit of measures were also confused, it was necessary to proceed along the time line for Atlas Charts to further our information concerning their inner workings and establish if the problems encountered were in fact solved.
Hence as the BNF Paris had excellent scans of the Atlases by Diogo Homen and that fortuitously they had featured in my first Portolan Book from Thames and Hudson, I knew they would shed light upon the subject. Thus a complete analysis of two beautifully drawn Atlases by Diogo Homen was undertaken, as well as an analysis of one of his excellently drawn Portolan charts, to establish the extra knowledge gained over the ensuing +100 years from 1434 to 1559AD. Unfortunately the results were very disappointing and add little to the original data which has been compiled as the problems persisted with no new knowledge.

The text consists of 6, A4 pages and contains 17, A4 diagrams

Throughout previous texts I have shown that the inner workings of Portolan Charts and Atlases indicate several distorting factors which have the effect of slewing the chart anti-clockwise from c3 to c11 degrees. That difference can be evaluated as the accuracy of the charts author in his draughtsmanship. But a study of the Iberian Peninsula showed that the basic slewing was in fact c12 degrees and emanated from one single fact; the draughtsman had used two distinct measurements for a degree of latitude which are in fact the same measurement in different forms but had used a single scale bar to measure them, thus totally ruining any accuracy that may have been possible. Therefore the Iberian Peninsula has the in-built potential to totally slew the whole chart by c12 degrees.
But that appeared to be a rather curious situation akin to the tail wagging the dog.
Thus I considered that the problem is in fact the opposite; that is, the chart was first drawn with a 12 degree slew anti-clockwise, then the Iberian Peninsula was tacked onto the chart, which would be correct if it was, as I have suggested previously a Roman Map. As the Roman World expanded the chart grew to encompass all of their lands and thus was not necessarily at first a full Mediterranean Sea basin map, but evolved from several forms.
Marcus Vipsanius Agrippa produced a “world” map in c11BCE following a “world survey” instigated by Julius Caesar in c54BCE, and that map was displayed in Rome.
Thus using extant Roman Texts this paper sets down the scenario for the 12 degree slewing of one of the original Roman Charts and how it developed into a Portolan Chart.
I have added to this text the work by Joan Blaeu, not for his charts but for his written words which discuss many of the problems I have uncovered.

This paper contains 19, A4 pages and 17, A4 diagrams.

A fellow researcher kindly sent me a copy of his paper regarding the “Enigmatic Chart” by Baldassare (Maiolo) Maggiolo, dated 1589 which appears to be drawn as four atlas pages each rotated 90 degrees from the next thus forming a rotating vista. That original text (q.v.) is predicated upon pixel measurements which to my draughtsman skills implies accuracy far in excess of that achievable in the 16th century, and does not allow for the vagaries of the charts actual drawing which was to be explored. My interest was thus piqued and I decided to explore the charts inner working and format which was made even more fascinating as the original text included a thumbnail copy of the Munich chart from Sir Robert Dudley’s Dell’Arcano del Mare. That original text stated “une carte tres similiare”, but then ignored it.
Thus there are two “enigmatic charts” which together may answer the question regarding their extraordinary presentation I therefore explore both, and with their idiosyncrasies endeavour to explain their raison d’être. The original text, chart and Munich chart are appendix notes.

This text contains 9, A4 pages and also 30, A4 diagrams.

The text is in two distinct sections; firstly an analysis of the chart dated 1500 noted as being by Juan de La Cosa to understand how it was drawn, the measurements used and the probable origination of the data used; and secondly an analysis of the “raw” historical data regarding the “La Cosa” personage and his exploits after stripping out the hyperbole and extravagant overstatements of many authors who have written concerning the whole subject of the exploration of the West Indies.
Both sections are written as stand-alone texts and need not be read as one paper.
This section casts doubt upon the authorship of the Chart and perhaps the date appended, as it appears to have information that was only known after the 1500 date and is thus thought to be 1502 at the earliest as others have suggested, but in fact could be even later. This section also questions the charts origination. The second section is merely the historical facts that can actually be accepted as such. But, as only confirmed fact should be used before accepting circumstantial evidence, and there being little definitive data to go on, speculative texts abound and they must be challenged. Both sections have their own Abstract/Introduction and they are not cross referenced to each other to allow the reader to reach his or her own conclusions from the evidence presented.

The part one text is 13, A4 pages and contains 28 A4 diagrams. Pages 1 to 13.
The part two text is 8, A4 pages and contains 1, A4 diagram, D01 from above. Pages 14 to 21.

Having read many texts concerning the Columbus exploits and thus knowing of Juan de La Cosa from those texts and his c1500 chart, I was totally bemused by the chauvinistic approach of many authors and how in each text new titles appeared when the historical facts did not actually agree. It appeared to me to be a little massaging and improving the data.
Thus I decided, but against my better judgement and contrary to my normal approach of analysing charts and maps, to explore at the most basic level the history appertaining to Juan de La Cosa. As has been stated by others, there is little hard evidence (or none in reality) regarding him prior to 1492. Even where he was born, his home village has been guessed by some when it is clearly written in a ships listing, but to establish the credentials of the c1500 chart the investigation is necessary.
In the first section I analysed the chart by draughtsmanship detail and now the second part is an analysis from confirmed facts with a timeline to establish the whereabouts of and the survey work Juan de La Cosa could have carried out.
Please note that to simplify references I am giving only page numbers from “Christopher Columbus, An Encyclopaedia”, edited by Silvio A Bedini, which was originally published in two volumes in 1992, but re-issued in 1998 as a single volume which is here-in used. I have and have also read numerous other texts and find that the basic facts remain the same throughout with some “gilding the lily” regarding the situation and others stretching facts to breaking point; one is enough!

The part two text is 8, A4 pages and contains 1, A4 diagram, D01 from above. Pages 14 to 21.

The Planisphere copy has garnered many plaudits from the historical and cartographical communities for its sumptuous presentation and scope of its geography. Many historians and cartographers have written treatises concerning its contents and endeavoured to illustrate that which it portrays through technical means.
Each and every one of these researchers has completely missed the most obvious and determining part of the design by generally adhering to preconceived ideas, instead of detailed analysis of the actual chart and its construction.
This text shows that the original Portuguese cartographer was a master artist and mathematician/geometrician who understood the necessity for constant measurement, but was thwarted by the data given which obviously consisted of a myriad of measurements named the same but wildly differing. Add to that the inability to transcribe Arab “Kamal” readings to either distance or latitude and only draw what was described thus the problems mounted.
The Planisphere copy must be investigated section by section to expose the problems the cartographer encountered, but overcame, to produce this feast for the eyes.
One question I fear will never be properly answered however is, “just how accurate is the copy we are now studying”? Personally I suspect that it is not copied, but the work of the original atelier, or persons of the original atelier and thus it is probably very accurate and the distance measures originally used are perfect, as the wind rose graticule which is so very accurately constructed illustrates.
Being produced by the original cartographic atelier, or those cartographers, it would explain other problems encountered in the research. That idea is very plausible as will be adequately indicated within the text pages.
Note; I have used my copy of the CD-ROM from Biblioteca Estense Universitaria for the Cantino research and diagrams illustrated. It was produced by Il Bulino + Y Press, 2004.

THE CAVERIO 1505AD PLANISPHERE
The Caverio 1505AD Planisphere has been variously quoted as being copied directly from the Cantino 1502AD, or as having very similar origins. Those are probably copies of copies of the “spare” planisphere no doubt kept by the original atelier for future charts to be drawn from. That it is a copy of a Portuguese chart is undoubted from its toponyms and content, but the chart requires to be analysed to ascertain its inner workings as they are not the same. The final analysis however must wait for the next text, ChFANO/1, which indicates that the chart is a pastiche of several charts and was probably started in Lisbon and finished in Italy.

The Cantino text is 10, A4 pages and contains 17, A4 diagrams.
The Caverio text is 6, A4 pages and contains 15, A4 diagrams. (total text 16 A4 pages)

It was a finely drawn chart which even in its present state of washed out presentation has many attributes, but, obviously the chart has been reduced in size to 1395 x 910mm, and before any investigation into its actual geographical portrayal takes place there requires to be an investigation to determine to what extent it has been reduced and thus what is “missing” such that a correct appraisal of the chart can be undertaken, This has been achieved using the wind rose graticule and its setting out. This I perceive nobody has bothered about before!
Then the drawn chart is analysed and compared to other charts which numerous researcher’s state quite frequently is probably a copy of the Cantino Planisphere or its derivative but it can clearly be shown to be from a different source chart. Finally the vexed question of attribution and date is addressed from viewing the actual script on the chart.
The text is 8, A4 pages and contains 21, A4 diagrams (A3 originally).
The postscript contains 26 photographs which were supplied by Biblioteca Comunale Federiciana at FANO of parts of the chart and are an excellent aid to studying its content.

Being unattributed upon the parchment itself, the format has led to many researchers speculating ad infinitum regarding its draughtsman/author.
Visual inspection can be self defeating when one chart is 1140 x 1790mm and the other perhaps only half that size. In that situation the eye of the beholder can be seriously misled. Thus this text sets down the investigation of the Pesaro Planisphere into its inner workings and compares it to those other charts speculated as being similar or perhaps by the same author, but the research uses the various chart forms as the arbiter of similarity with actual overlay illustrations.
The Pesaro Planisphere is beautifully drawn, is a one off in several respects and does not appear to be by any of the speculated draughtsmen/authors; but is it finished?
Note; this paper is a diagram based paper with limited but concise text, thus the diagrams should be carefully studied to ensure the various layers are fully understood. The diagrams numbers 15 to 24 are in fact 3 charts and they can be joined together by the overlapping areas to illustrate the complete comparison of chart to chart.( A4>A3)

The text is 06 A4 pages and contains 28 A4 diagrams, all of which commenced as A3.

Henricus Martellus 1491 and Martin Waldseemuller 1507 charts both exhibit a peculiarity in the draughtsmanship design of the African Continent. Thus it appears they were both confused by a similar presentation of a plain rectilinear chart they were using to draw their curvilinear world maps or charts. The reason for the confusion is amply illustrated by the King-Hamy 1502 chart which has two Equatorial lines; one for the western geographical section and one for the eastern Ptolemaic section, but they are shown as overlapping within the African Continent.
Also to be addressed is the confusion with the nomenclature researchers have used to describe the form of these charts. They are not cordiform or Pseudo-Cordiform but plain Ptolemaic projections as can be amply illustrated. The Martellus 1489 printed charts are nothing more than an inverted Ptolemaic First Projection and then the 1491 chart and the M.Waldseemuller 1507 chart are just a slightly modified Projection Two by Ptolemy.
Thus this text commences with the Geographike Hyphegesis of Claudius Ptolemy, explores the King-Hamy 1502 chart (D01), then an analysis of the Martellus 1489 printed charts (D02) and finally the Martellus 1491 chart (D03 & D04) and the Waldseemuller 1507 chart (D05). For all of these answers are given to the questions regarding draughting methods, construction and their presentation, including their errors and foibles.

The text is 15, A4 pages and contains 59, A4 diagrams (all originally A3)

Read research papers or books concerning Genoese 14th to 16th Century cartography and there is not one text written which investigates how it all happened and uses simple basic facts such as lifespan, training or raison d’être for the origination. The first extant work provable by attribution is that of Petrus Vesconte and his 1311 chart. But he had to be taught the art and that has never been addressed in the myriad of papers written over the last years. Add to that the Carta Pisane, probably 1290 and the Cortona Chart c1300, both of which have doubtful provenance, but by existing they push the date backwards for the training of their authors. Thus this text sets down clearly known facts and dates and uses the life spans attributable to evaluate the overlap of these cartographers and how their charts also spring from a basic pattern/template which is amply illustrated in the second part of this research.

The text is 20 A4 pages and contains 53 A4 Diagrams (originals are all A3, and some interlink to form the complete chart at large scale.)

Commencing with an in depth study of the actual draughtsmanship to explore the hidden features, the text then investigates the donor charts which allowed it to be drawn, much of which has been known for over 100 years, and finally shows that it is the latest manifestation of the “mappa mundi” genre which are usually drawn as circular charts.

The text is 10, A4 pages and contains 21, A4 (A3) diagrams

Searching for information regarding a Globe which I thought had dubious attestation given by J L Stevenson, Tome 2 pp47/49, regarding Petrus Plancius, I was led to the BnF Paris and a set of Gores available under their Gallica system. To my surprise I found them to be wrongly drawn and did not include the three texts quoted by Stevenson. Hence a very fast research project to find the globe ensued whilst I awaited a Portolan Chart scan to arrive.
The outcome of this research is quite surprising to say the least! And, it is merely a quick resume of the facts I have so far discerned requiring a proper research project later.

The appendix is perhaps the most surprising find, geometric errors by Mercator!

The text is 6, A4 pages and 17, A4 diagrams or photos.

The text “Using a Portolan at Sea, did they?” indicates quite clearly the nonsense of considering that at any time a magnetic compass was used for either route sailing or the construction of a Portolan Chart. The latest paper available, “The Maghrib’s Medieval Mariners and Sea Maps; The Muqaddimah Primary Source”, explains precisely what a “Compass” is, and it is not magnetic. Then in this text, having followed the development of Portolan Charts from their Genoese foundations in Italy, and after via Majorca and onto Egypt these two charts, one drawn in Tunis, the other certainly Arabic, but unknown are investigated. The Tunis chart is a standard Portolan, but the Maghreb chart is probably an atlas page and these are to be examined apropos the Genoese and Majorcan continuity of chart design. The indication is that the setting out of the wind rose graticule is a perfect copy of the Petrus Vesconte 1318 Atlas page which illustrates the methodology of how to draw the graticule sans circle, and these charts are typically the follow on product of Genoese charts.

THE TEXT IS 10, A4 PAGES AND CONTAINS 22, A4 (A3) DIAGRAMS

The atlas dated 1511 was obviously drawn in 1510 and contains a very mixed bag of charts. They are all investigated, but the sheet numbered 08658-001 by the JCB Library, the so called Dedication page, is investigated separately as a stand-alone section text, ChAVM/2.
The atlas comprising 10 sheets was composed with several scales being utilised for the various charts. These do not at first appear to be interlinked as the atlas has obviously been re-configured in the distant past, a fact borne out by the attempts at alteration on a chart. Therefore not being as originally composed I have suggested the original order of the charts which make logical use of them as their scale bars indicate. Vesconte Maggiolo has included his version of the first projection of Claudius Ptolemy using an amalgam of old and new charts as many other cartographers of the age have. There is also a cosmography which in fact is rather redundant as a useful tool. As I surmised in my text ChGEN/1, the whole atlas required to be drawn from a complete Portolan Chart and it appears in the investigation.

The text is 6, A4 pages and contains 49, A4 (A3) diagrams.

A historical and technical examination of the sinister and dextra parts of the Dedication page, JCB 08658-001, illustrating the Armorials of the titular heads of Corsica on the sinister and a map of Corsica with toponyms and four elaborate monograms on the dextra. It is not a definitive work as it must be further investigated due to the complexity of the subject and a distinct lack of detailed information. Speculative in part it certainly is!

The basic facts are laid down with conclusions where possible regarding the Armorials, but the Map of Corsica and its toponyms is analysed completely and there only exist one or two curious place names that are unknown today. However in comparing this map to others it proves there are always curiosities.

There is also an appendix which discusses the cartographers in Naples c1510.

The text is 11, A4 pages and contains 25, A4 (A3) diagrams

Having investigated the JCB held atlas of 1511 to evaluate its geography in text ChAVM/1 and ChAVM/2, this text adds the geographical information from the 1512 atlas held in Parma and the 1519 atlas held in Munich. All three are compared to each other to establish the continuity of their construction.

Thus it is possible to opine that Vesconte Maggiolo had with him on his 1508/1509 journey from Genoa to Naples a Portolan Chart and in all probability a pattern/template with which to construct these atlas pages. They are quite accurate in their comparative state when the scale bars are aligned and they are overlaid one on the other as the diagrams clearly illustrate.

However, this text commences with Section 1 a retrospective analysis of the 1511 JCB atlas page sizes to determine how Vesconte Maggiolo actually scaled certain sheets to fit precisely to the page size of c39 x c57.6 cms. This investigation proves the use of the Roman Uncia for some of the charts construction and also that the charts are in a mathematical ratio of size with a rather extraordinary finale.

Section 2 is then the comparison of the three atlas and their inner workings and illustrates the previous findings of continuity of pattern/template.

Section 3 is a comparison of V. Maggiolo and Salvat de Pilestrina’s work which shows they are probably identical and thus from the same pattern/template drawn in Genoa.

The text is 10, A4 pages and contains 50(51), A4 (A3) diagrams, (one is a double)

An atlas of 20 sheets plus two cosmological pages which form two complete (nearly) charts, one being a Portolan and the other a Planisphere. A peculiarity of presentation gives rise to a comparison, unfounded, to Vesconte Maggiolo 1511 Atlas, and the date must be assumed from the beginning of the cosmological information commencing January 1508. The data is presented as found including many Greek toponyms combined with Italian toponyms and also with the historical items included help conclude it is a Genoese product c1507.

The text contains 5, A4 pages and has 23, A4 (A3) Diagrams

A very short technical appraisal of the works by Piri Reis, debunking previous texts and scholar’s comments, dismissing wild theories via what the charts actually show, not what people wish to believe from preconceived ideas and establishing the credentials of Piri Reis as a mathematician as well as an obvious accomplished draughtsman.
The text is 6, A4 pages and contains 18, A4 (A3) diagrams.

There are five large similar planispheres of which two are clearly “signed” by Diego Ribeiro with the other three nearly exact copies and thus capable of being assigned and dated. This text concentrates on two examples. The first is dated 1525 on its Astrolabe diagram and by a text note, but it is one of the “unsigned” examples and held by the Biblioteca Estense Universitaria, Modena, Italy. The second is the 1529 planisphere, dated and signed and held in the Vatican Library. There are numerous texts discussing the work of Diego Ribeiro but not in a technical manner to explain the knowledge contained there-on, their foundation for design or explain the visually complicated “Declination Diagram” in a simple manner for it to be utilised.
Many other authors have implied that these five charts are in fact as near as possible to the Spanish Padron Real, the Royal Standard Map of Spain. That being the case then it is proven beyond doubt that the Diego Ribeiro Planispheres are the “mythical” Square Chart and thus the Padron Real of Spain is also a Square Chart, latitudes and longitudes are equal and there is no sign of a magnetic slewing of the Mediterranean Sea, it is geographical.
It is also possible to conclude that Diego Ribeiro was a consummate polymath and probably knew M F de Enciso in Seville when his “Geographia” was published in 1519 and certainly Ribeiro has used his text to illustrate these five planispheres.

The text is 9, A4 pages and contains 34, A4 (A3) diagrams.

Held in the Library of Congress are two charts noted as Vellum 9 and Vellum 10. They are very distressed and obviously reduced from a larger format. Dated to C1500 and C1565 because of their visual attributes they have also been noted “as seemingly sharing a common provenance and history and are therefore considered together”. However it is noted the Cartographers are possibly different; that will be dis-proven.

Vellum 10 has a “signature” which appears to have been ignored by the Library of Congress cataloguer and hence this text follows the trail found within the charts to explain their probable provenance and country of origin and the surprising mentions. It is not an orthodox paper, more a journey of discovery.

This text contains 11 A4 pages and 27 A4 (A3) diagrams.

Bartolomeu Olives is the younger brother of Jaume olives and has Portolan charts to his name dating from 1538 to 1588. They are mostly drawn in Messina Sicily, but he/they commenced in Majorca and had a brief foray to Venice. This 1584 chart is held by BNF Paris, Departement of Cartes and Plans, reference CPL GE B-1133 (res), and is an extraordinary compilation. Excluding the standard toponyms it is scattered with Kings, Dukes and large writ place-names which at first sight are a strange combination.
This text analyses the chart as drawn technically and then endeavours to unravel the reasoning behind these place-names and in the process finds a 1500 year history lesson with a rather chilling raison d’être of persecution and conquest written there-on.
The text contains 12 A4 pages and 25(29) A4 (A3) diagrams

Bartolomeo Crescenzio suddenly appears in the records when he publishes in 1595 his first text, “Proteo Militare” written in c1587. He is an Engineer of the “Papal Fleet” and obviously an educated person. The next work is a “Portolan Chart” dated 1596 on which he declares it corrects previous chart errors. He then writes a second text, “Nautica Mediterranea”, published in Rome 1602, which includes the simple chart inserted previous to a Portolano text of 63 pages.
The whole oeuvre of Bartolomeo Crescenzio is analysed, discussed, and a rationale for their existence perhaps uncovered. There is then an appendix which mentions a 2021 text making unattested claims for the 1596 chart and another of 1525.
The text is 15 pages and contains 24, diagrams, (A3)

The paper is in two distinct sections;

1) A complete analysis of the world chart including a comparison which may indicate a similar cartographer.

2) An analysis of the vellum/parchment itself to expose some very peculiar features.

The text is 6, A4 pages and contains 18, A3 diagrams.

In HOC 3/1/7 and /40 basic facts are set down concerning Domenico Vigliarolo regarding part of his life and some of his works. The then known items were 4 charts and an atlas, but since that publication a fragment of a Vigliarolo chart has been found in the Notarial Archives, Malta, and a chart held by the Vatican Library has been identified as his work. There is also the chart held in the National Library of Wales drawn in Seville, 1592.
This narrative sets down a timeline, considers where he was trained, his possible teacher and the charts relationships one to the other. There is then an appendix referring to the Wales chart and a curiosity which leads to another text and chart.

It comprises 11, A4 pages and 41, A3 diagrams, some originally larger and reduced.

A brief narrative following the discovery of a Chart fragment, its conservation and my investigation to trace the cartographer and thus the possible date of the chart.

The text is 3, A4 pages and contains 7, A3 diagrams

An investigation that analyses these 10 atlases and uses as the base guide the Dresden Library Atlas, dated 1568 which has 28 folios and is thus possibly the most expansive atlas produced. It covers the discoveries to that date, the technical data and also includes a World map and the Clima Zones.

Only three atlases have world maps extant and their provenance is investigated.

There already exist two texts, ChDgH/1 and ChRH/1 which discuss works by the Homem Family and should be considered part of this text.

The text is 7, A4 pages and contains 38, A3 diagrams (many larger reduced)

Having waited several months for photos of the atlas to arrive, as the Library said it was in a poor state of preservation, and the fact that they then sent 26 photos including views of the bindings and covers this atlas was chosen for a singular study. This was mainly because of handwritten texts on the inner bindings of the front and rear leather covers. On first viewing they appeared to contain both good and spurious information and it piqued my curiosity. I had already noted that four of the folios appeared to make a portolan chart and thus an investigation was required as to the original chart that was copied to form the Atlas.

I was not prepared for the research necessary to answer the reasoning for those texts and thus a separate appendix text was required.

The text is 3, A4 pages and contains 17, A3 diagrams.
The appendix is 11, A4 pages and contains 3, A3 diagrams.

The Fra Mauro Planisphere is housed in the Biblioteca Marciana, Venice, and has been the subject of two books, one in 1956 and the latest by Professor Piero Falchetta in 2006. This latest text included a detailed listing of toponyms and textual notes and was accompanied by a reactive CD scan of the planisphere.

This narrative uses the excellent work of Professor Falchetta and seeks to find the path that Fra Mauro followed to produce the 1960mm diameter planisphere which is a work of outstanding beauty and was preceded by other smaller portolans, equally well drawn.

This text evaluates the scale of the planisphere and thus contradicts the Book regarding its construction merely by following the path Fra Mauro took in its production. The work of the copyist who produced the Vatican Borgiana V Portolan chart and the work of Andreas Bianco are obviously keys to the whole subject. Finally it questions just when it was finally finished?

The text is 9, A4 pages and contains 22, A3 diagrams

Contacted again by the Notarial Archives of Malta, when they discovered in 2021 this larger fragment of a Portolan Chart it was a pleasurable surprise and a wonderful challenge. Because of the ensuing travel restrictions it was not possible for me to fly to Malta (yet again) and I had to rely upon the Archival staff who were charged with securing the Archives for posterity to photograph as best possible the remnant.

They have taken numerous photos which are all pre-restoration state of the fragment and that made the task more challenging, but, a systematic approach was required as well as some specific photographs that were requested and supplied to supplement the data..

This short narrative text relates the research story as it unfolded over the year to the point where the cartographer was discovered with the help of those on Malta. However, it is only a preliminary narrative text as the contents will clearly indicate.

The text contains 06, A4 pages and has 15, A3 diagrams.

“Cartographfia Mallorquina”, sigilo IV; LOS RUSSO, LOS PRUNES, has the following; Russo. Pietro (Messina) (XV2.1508) and lists four charts as follows;
S.XV 2 Conte Giul. Merenda, Forli, en. (Messina)
1508, Coronel Torrens, Madrid, en. (Messina)
S.XV2 BN Paris, en (Genoa) (attrib)
e.Xv2 BN Paris, en. (?) (attrib)
and in the Bibliografia for s.XV2, Conte Giul. Merenda, Forli,
U>A>; p280 (Uzielli Giuseppe y Amat di San Filippo, Pietro) (Mappamondi carte nautiche portolani, Rome 1882, Societa Geografica Italiana XXVI)
One would have thought that S.XV 2 was a well recorded Portolan Chart, but it took from mid 2020 to April 2022 to find and obtain a copy. The sequential story told here-in is a record of a simple search utterly frustrated by the horrific consequences of a ferocious bacteria, and the very necessity of records being well maintained and properly shared.
I must say here a big thank you to Deborah Shapiro and Joan Boudreau of the Smithsonian Institute, who even working from home with infrequent visits pulled the rabbit out of the hat!

The text contains 07, A4 pages and has 16 A4/A3 diagrams (including appendices)

Rather late in the context of Majorcan/Catalan influences, but having written ChGME/1 linking those charts by author and teacher which basically finished as a text c1500AD, this text nominally follows two dynasties from c1470 to c1640. It concentrates on information on those who influenced them and whom they influenced but only the work of the Rubeus/Russus Family is fully discussed. The Olives family is basically noted as a time line and it should be noted that the first two Olives family cartographers have 35 charts between them extant. They are included as the Cartografia Mallorquina listings combine them and the cross fertilisation through the ages can be indicated.

However, the preceding text, ChCGM/1, sets down the basic facts concerning the first (?) chart by Petrus Rubeus, that once owned by Conte Giuliano Merenda of Forli and the full research texts I found from the 1880’s , 1957 and 1970. They are only referred to here-in and thus for the full storyline that text should be analysed first, particularly the appendices.

Prior to my conclusions on this text there is a section headed “Why did Petrus Rubeus leave Majorca for Messina?” This is an attempt to reconcile many questions which arise in this text and have perplexed me and endeavour to answer the question, Why Messina?
Finally I have appended the text from ChGME/1 Appendix which discusses Rubeus/Russus.

The text is 9 (25) A4 pages and contains 31 (27 +4 APP) A4 and A3 diagrams.

In studying the charts and atlases, I noted that there was a significant number of Mythical Animals and Christian Iconography there-on. Bartolomeo Olives is obviously “Catholic Majorcan” and thus I would expect there to be some reference such as the vignette of the Madonna and Child on the neck of the vellum, but, having written ChBAO/1, a text detailing the Bartolomeo Olives chart dated 1584, which I sub-headed “History Writ Large on a Chart” I was not surprised to see that others were so detailed.

Thus the criteria for this text, starting with his probable cartographic training and thence his move from Palma Majorca to Messina Sicily, was to determine just what his raison d’être was for appearing to be an educator as well as a cartographer.

Please note that I have a copy of all Bartolomeo Olives’ Atlases and charts except a privately owned chart, as noted. However not all of them are actually shown as copies but are all described here-in; certain charts as noted may be extant but missing.

The text is 20, A4 pages and contains 23, A3 diagrams

Although two excellent texts regarding the work of the al-Sharafi family of Sfax Tunisia exist, they do not address the works from a draughtsmanship or even technical stand point which is necessary when it is stated they are all “copies”(?) of other cartographers work. Also those two texts do not utilize the statements within the three extant works to uncover a strange story line. Even acknowledged experts on Islamic works have missed their importance as these would not have been written if not correct, or at least highly indicative.

Within the al-Sharafi works are excellent hints at the actuality of what is extant and what is missing. This text uses the words of the al-Sharafi clan to uncover a story line and discuss the very apparent errors on the atlases and chart(s).

The text contains 15, A4 pages and 20, A3 diagrams (Appendix included as text)

Jaume Olives is the elder brother of Bartolomeo Olives and hence putative head of the Olives clan of cartographers. However he is also perhaps the least known of them all and thus the search for his history and the placing of his charts in the overall pattern of nautical cartography is not an easy task.
Therefore what follows may leave some gaps in the overall storyline to be filled with possibilities, but overall a life does appear along with the Portolan Charts and Atlases.

The text is 09, A4 pages and contains 25, A3 diagrams

Because of the text by G Caraci postulating that the 1574 chart could be either its brother I have appended a short narrative which is quite conclusive on its cartographer.
The text is ChCNM/1 and is 2 A4 pages, and will become a full text ChBOL/2.

ABSTRACT
Two very differently presented planispheres with a basically similar world format and containing copious texts as well as additional side pieces. The texts are in all probability copied from another source and are not by the cartographers. A major problem is that Sebastian Cabot did not draw the chart which bears his name, it is an engraving of a chart thus earlier than the 1544 date which appears on the chart. The format is surprising in that it is only one of a very few charts of such a size to be drawn as an oblate spheroid which as will be shown presented very many problems for the engraver. It is also visually perturbing in that the deformation of the continents is so very obvious. The Sancho Gutierrez planisphere is however a more normal rendition of a chart, that is it is four square, equal degrees and follows the original Portolan charts basic methodology. Both charts feature a very special cartouche of an Eagle which is a link to other charts and atlases being drawn in that period.

Having read various texts concerning these two planispheres and being of the opinion that the idea they were somehow copies was rather spurious and thus it became necessary to investigate them both and quantify their contents. One text however, mentioned at the end of this text will provide the details omitted here-in. This is a text about the cartography there-on.

The text contains 8, A4 pages and 12, A3 diagrams

A chart and an atlas signed “ANGELUS” were supposedly drawn in Marseilles, 1571 and 1575. However viewing them immediately raises many questions as it is obviously not one persons work, unless it is spread and held for some 20 years as the earlier work is poorer than the later work. But, it may even be a case of subterfuge as it is quite likely another person’s work has been used in the atlas. This text explores that question by describing the two works in detail and comparing them to other extant works and has surprising results.

The text is 11, A4 pages and contains 28, A3 diagrams.

A new text published in “Imago Temporis. Medium Aevum, XVI (2022) pp389-432, endeavors to make the case for the unknown author/cartographer of the King-Hamy chart to be Baptista Agnese and the date not 1502 but 1536-1564.

This text queries both arguments and discusses the proposed date change for the Baptista Agnese 1514 to 1554, (Wolfenbuttel).

The text is 04, A4 pages and contains 09, A3 diagrams.

The 1602 map is covered in texts, place names and geographical information which includes its setting out in a form of rectangular elliptical projection. It utilises the curved meridians to replicate on a flat plane the spherical nature of the Earth itself. This form of projection is in many guises on maps of the 1500’s, with variations mainly to the radii setting out. It has also in the corners four small charts on an azimuthal projection. This is studied and the setting out confirmed. Matteo Ricci, born 6 October 1552, died 11 May 1610, China.

ChMR/1/ABS

In the maps appended text Matteo Ricci states; “Now the real shape of the earth is spherical, where-as in the present map it is a flat surface, so that the truth of the matter is not easily comprehended at a glance. Therefore, again following the plan adopted in my own country, I also drew two hemispheres, one showing all that lies north of the equator, and the other all that lies south of it, the two poles falling exactly in the centre of the hemispheres, so as to give some idea of the real shape of the earth.” Thus we are told it was an Italian Map he has copied for these hemispheres.
Also in the text appended he clearly states ,”The prime meridian passes through the Fortunate Islands; hence Nanking is situated , 32N latitude and 128E longitude”. However, he then choses to set the perimeter bordure of the map 10° to the west of those Islands; Why?.

Then either fortuitously or a serendipitous occurrence we see that at 10° east the Islands and the west coast of Africa is marked ( it is actually at 17° W geog), and at 20° further east we have a meridian passing directly through LONDON, and correctly through the Mediterranean Sea and Africa marking the Geographical Longitude for the World.
Following that, why precisely 180° from the western bordure is the meridian set along what is obviously the International Date Line, set through the furthest east point of the major Eurasian Continent adjacent to the Bering Strait?

Regarding the Equator, he write as follows; “This central line of equal days and nights, divides the earth into two equal parts. All that lies above it is north, all below it is south. The countries lying near this line the seasons are each a month and a half in duration, there being eight seasons altogether in the year, two springs, two summers, two autumns, and two winters. The four seasons of the Northern region are opposite of those in the southern region: when it is spring in the north, it is autumn in the south: when it is summer in the north, it is winter in the south. The reason apparently is that the rays of the sun have to travel a greater or lesser distance, respectively.” Thus apart from the first section of that text, it clearly shows an understanding of the tilt of the earth and thus the change of seasons.
Thus we have a rather surprising set of occurrences drawn on a map of 1602, indicating decisions taken in the 19^th century and these must be investigated.

The text is 08 A4 Pages and contains 14 A3 diagrams. It contains a copy of text MS7 as an appendix and then totals 21 pages including MS7 diagrams.

The first paper ChCATA/1 published in February 2019 was a brief exercise of analysis to ascertain the physical works to produce the Atlas, its construction and knowledge c1375CE.

The paper determined that it was not a coherent single work in that the folios were based upon two setting out forms. A set of horizontal or latitudinal lines and a wind rose with a different basis. It also concluded that only one junction of the folios was accurate, one had major over-lapping which in the south was awry and the 3rd/4th extant folios did not in fact join at all. The conclusion was that between folios 3 and 4 or sub-folios 6/7 there was a missing folio.

At the time of writing ChCATA/1, the very arduous work load of identifying each and every town on those sub-folios was not possible and hence the obvious positional problems and duplications were not discussed. It was also perhaps a “lost cause project” as without the missing folio, many assumptions that were required could not be tested.

However, that work has now been carried out and the missing folio c650 x 500mm tentatively infilled with some missing geography. Obviously it is a “curates egg” just as the original Catalan Atlas is.

It is up to the readers of this latest text to make up their minds on the proposals.

The text is 08, A4 pages and contains 16, A3 diagrams.

Only four items thought to be by Bartolomeu are extant. Two are named and dated and two are both surmised for attribution and dating.

They are ; 1) 4 charts making a planisphere; 2) A Cosmographia; 3) an Atlas & 4) a Gore diagram showing the World. These are totally different in their being and thus presentation. The four charts making the planisphere are each c800 x 1200mm, dated 1561 and are the earliest of his works (see later) and contain a large amount of subsidiary data which indicates his mathematical skills and astronomical knowledge.

Nothing is known of his birth date but to gain the skills illustrated how he was educated and where would answer a lot of important questions. The scope of his knowledge is therefore one item to be discussed, the planetary science, the mathematics and subsidiary data which come from his Cosmographia of 1568 as well as his comments on the instruments of navigation form part of the research.

The Atlas ( attributed and undated) has a peculiar form of presentation which makes for an awkwardness in trying to gauge the “world picture” and is thus reset in an order.

His diagram of 24 Gores in circular form is again an awkward presentation and perhaps borne out of his desire to impress the King of France with his ideas.

That he died in peculiar circumstances is documented by the Obituary texts added to the cosmography and give it its date of 1568, which is challenged.

The text is in four sections in a revised date order to that given in PMC, which is explained.

Each Section has a separate heading and number such that it can become a stand- alone text. ChBV/1; ChBV/2; ChBV/3 and ChBV/4, with diagrams numbered sequentially.

THE WHOLE TEXT IS 11, A4 PAGES AND CONTAINS 35, A3 DIAGRAMS AND ALSO HAS AN APPENDIX OF 1 PAGE AND FIVE DIAGRAMS. (Total 12 +40)

During the 1500’s the charts were able to map the exploration of West Africa carried out in the late 1400’s, and then the gradual expansion of the known world as ships of many nations sailed both south then east and south then west from the Strait of Gibraltar to eventually encompass the whole 360 degrees of the Earth.
During that time many assumptions had to be made from the meagre data given by returning sailors. This led to cartographers having to “second guess” much geography to enable charts to be comprehensive. They also had to infill land masses with spectacular views to hide the fact that there was no hinterland knowledge.
Given also the supposed secrecy of discoveries made by Portugal and Spain and their respective “cartographic houses” vying to out-do each other, including ensuring that the “Treaty of Tordesillas”, when delineated on their charts was advantageous to each, actually by the political chicanery of cartographers, there tended to be wild variations.
This text merely notes the curiosities of the Portuguese Charts, Atlases and Planispheres as the world enlarged and the charts expanded in size to accommodate the 360 degrees, and finishes with a very peculiar atlas and its journey to the BnF Paris.

The text is 14, A4 pages and contains 25, A3 diagrams.