GENOA; EXCELLENT MARINERS AND CARTOGRAPHERS, BUT WHENCE CAME THE CARTOGRAPHIC TRAINING?INTRODUCTION
In my earlier papers which are all cross-referenced here-in, I surmised that the origination of these charts was from “Roman Maps” of “Mare Nostrum” (text Ch12°/1) There are two deliberate sections to this text with the first dealing with a summary of the historical knowledge and the cartographers that appear in the records of Genoa, and the second section an analysis of their charts to indicate the continuing use of original data. However to proceed with the research I must first establish the possible life spans to enable a training period to be evaluated and if the preceding cartographer could therefore have trained others and then posit the theory of why they do not appear to be numerous perhaps because of a distinct lack of monetary gain from their profession.
I have used as my text guide the book by Gaetano Ferro, “The Genoese Cartographic Tradition and Christopher Columbus”; 1996 English version, rather than provide the extensive list of my researches into the subject and expand the text un-necessarily. It can be used as a general guide for the research and contains much but not all of the historical knowledge available.
LIFE SPAN EXPECTANCY
In The Lancet, February 1975, I.C.McManus wrote an intriguing short article entitled “Life Expectation of Italian Renaissance Artists”. He produced data in the form of two tables, here-in reproduced for Artists born between 1250 and 1550 which show only small differences for those born pre or post 1450. Similarly no major differences were found between those Artists working in Florence, Venice and Central/Northern Italy. Thus taking the quote from Psalm 90 verse 10, “The days of our years are three score and ten”, we could consider it a realistic option, but unfortunately infant and child mortality in Renaissance Italy and Old Testament Israel were probably very high and their survival did not necessarily attain any useful age, thus the number of children available to train was probably quite limited.
Of the 218 Italian Renaissance Artists according to age at death we see a peak number at 55 to 70 years of age, but when you study the table for, “Mean, S.D. and Median duration of life” a clear median of 65 years appears.
ChGEN/1/D01
Thus that is the age length used in the text tables which follow to investigate the probable Birth, Life and Death of our cartographers, unless of course we have documentary proof of the dates. My basic assumptions are always; Youth, 0-10 years: Apprentice or Clergy, 10-20 years: established as cartographer 20-25 years: and then the following 40 years of possible active life, be it charts or training apprentices or another occupation in a different city to gain a living wage.
NOTE; As you can see from the tables I have prepared it would not have materially changed anything had I chosen to use threescore and ten. But having obtained this excellent data it had to be used. But the interesting portion of the data is that the child mortality rate was very high and it probably accounts for why we do not see son following father into cartography in Genoa until c1500, but that could be a one off occurrence as is to be discussed.
TABULATION OF LIFESPANS
The tables I have set down indicate firstly (ChGEN/1/D02) a general lifespan for each cartographer (or Anon Chart) that is part of this study. It is a bar chart with the 65 year span set out as per the basis already discussed and indicates quite clearly the overlapping lifespan from c1260 to c1580AD and thus the distinct possibility of them being acquainted.
ChGEN/1/D02
ChGEN/1/D03
ChGEN/1/D04
The following two tables (ChGEN/1/D03 and D04) are to be joined as they provide for a continuous storyline commencing in 1395 with Francesco Beccario (1360-1426) and through the four sections, 1395-1433; 1433-1471; 1471-1509 & 1509-1547, deal with the Genoese cartographers and those whom I believe obviously influenced or shared a common knowledge/training source. I finish the listing with Vesconte de Maggiolo (1470-1549) and Giovanni Battista Agnese. I have subdivided each lifespan, by years 10/10/5/40 and indicated chart dates and other pertinent activities as found in the records.
I believe these tables clearly indicate that the training and working periods are closely intertwined such that Clergymen and jobbing cartographers are together at singular periods and that in all probability the Clergy all had training in one establishment, probably a scriptorium attached to a Monastery in NW Italy. I reiterate the point previously made that altering the lifespan length or adjusting the lifespan positions on the years makes little or no difference to the probable linkage from cartographer to cartographer.
PART ONE OF TEXT
THE EARLY YEARS; SUMMATION OF KNOWLEDGE
The oldest extant charts are the “Carta Pisana”(ChCPS/1)(ChGEN/1/D05) and “Cortona” (ChCOR/1)(ChGEN/1/D06) dating from c1300AD and the Luxuro Atlas dated c1300/1325(ChGEN/1/D07). We know nothing of their authors or precise dates but various researchers have agreed they are probably Genoese in origin. Starting with the “Carta Pisana” which I have already written about as text ChCPS/1, I consider it to be a palimpsest because of the obvious scratching out of sections and the horrible rectangular forms drawn across the chart. This is no doubt to hide other removed sections (they are diabolically drawn compared to the charts coastlines) and shows that whomever drew the original had had training in the art in the 1200’s and thus we can assume there was a “cartographic school” in a scriptorium where the art was learnt, or that there are older cartographers totally unknown to us who reverse the beginnings probably as I have surmised to the 9th century. The cartographer must have been taught!
ChGEN/1/D05
ChGEN/1/D06
To put it plainly; a person does not just pick up a quill pen or pens etc and decide to draw a chart of the Mediterranean Sea area. It is utter nonsense to even consider it a possibility when the work involved and the knowledge required is accounted for. The only method possible to start immediately would be a highly trained individual in script and miniatures, the use of a quill, mixing inks, scale and proportion to copy an extant chart. And that is highly unlikely as given the apparent problems with monetary gain for a chart they surely would be sold immediately and thus that person could only be part of a family who purchased the chart, or related to the original cartographer.
And thus we return to a scriptorium and monks who have been schooled for years to produce high quality (although not always perfect) copies of texts etc.
Therefore if we accept the 1290 date for the Carta Pisana the first cartographer who drew the coastlines was in all probability born around 1260/1265, thus leaving a 10 year period for youth or prior to entering a monastic establishment and then a 10 year apprenticeship to achieve the high standards of the art. Finally a brief period, c5 years before the separate commission was given to produce a chart and thus this timescale will produce a lifespan of 1260/65 to 1320/25, by my chosen methodology.
We are therefore at a Genoese commencement date, be it via private cartography or a scriptorium of c1200/1250AD.
ChGEN/1/D07
At this point I will mention the Luxoro Atlas of which 4 double pages exist. It is sometimes referred to as the Tammar Luxoro Atlas and has been linked to Petrus Vesconte, (ChPV/1) but with a range of dates given from 1300 to 1325 by researchers it is hard to see the presentation as Vesconte’s because of the fact that a chart is required from which to compose Atlas pages. If it was Vesconte then I would expect an early chart before 1309 and possibly the Riccardiana Ms 3827 chart, and then the Tammar atlas in 1310 as the Vesconte calendar of extant works only has a window from 1314 to 1317 and by then his style was well advanced, far better than the Tammar Luxoro Atlas.
ChGEN/D08
On a lifespan basis Fra Giovanni Mauro da Carignano (ChGEN/1/D08) whose chart was drawn in 1320/25, dated by the Aragonese Coat of Arms on Sardinia, his lifespan can be surmised. We know he was at the Genoese church of San Marco in 1291 and appears to have died between September 1329 and May 1330, which dates would give us a birth around 1265AD. On that basis we can extrapolate a life and assume he started Holy Orders at the age of 10 and was 20 in 1285 when possibly appointed a Presbyter. But that leaves a period of 25/30 years before the chart, “Presbiter Joannes rector sancti marci de janua me fecit”. By using the Aragonese Flag on Sardinia as a dating tool it does not mean the chart was not drawn much earlier and annotated as and when during the Frater’s life. The Frater would have been c55 years old if the dates given are correct. Thus we must ask if He learnt his cartographic skills c1275/1285 or are they a later accomplishment when the Church of San Marco became a repository for “shipping paraphernalia” and it went with the whole ethos of serving the mariners. But of course He required to be trained in the art and the aforementioned cartographer was probably around! But, I think with the amount of research already carried out we will never know.
The first and most important Genoese cartographer of this age is Petrus Vesconte (ChPV/1)(ChGEN/1/D09).
ChGEN/1/D09
He undoubtedly commenced his career in Genoa but decamped for Venice, perhaps merely for financial reasons as c1250/1300 it appears cartography may not have been a valued profession. But as Petrus Vesconte signed and dated his works we can establish a time-line. The first extant chart is dated 1311 and thus applying the formula of 10+10+5 years we can surmise he was born c1285 and thus his span ends c1350AD. His extant works are from 1311 to 1327 and include charts, atlases, mappa mundi and maps for texts by others (ChMAT/1). It is a prodigious work load and would have been continuous for the 16 years given the timescale required to actually carry out the draughtsmanship. And we must note that in his 1318 Atlas He sets out the mathematical basis for drawing a Wind Rose sans compasses, (ChWR/1&2) and thus we must add to his training mathematics and geometry and thus He had the highest form of apprenticeship available in that era. Again I return to the facts available; only the monastic institutions of that era were capable of such training unless Petrus Vesconte was placed with a highly educated person who knew the Arts, calligraphy, mathematics and draughtsmanship skills required, and I suspect there were not many such person around at the time. I will therefore quote directly from Gaetano Ferro’s book, pages 28/29 to conclude this part and commence the next.
“One of these planispheres, then, is found even among the maps of Marin Sanudo’s “Liber secretorum fidelium”(1306-1321); the maps were inserted into the book that the Venetian presented to Pope John XXII in September 1321 in Avignon in order to illustrate his plan for a new crusade. Today all scholars agree that these maps are the work of Pietro Vesconte, a Genoese, even though he almost certainly executed them in Venice”.
“The Holy Land, therefore, is still the centre of the earth and thus re-echoes themes from the geographical and cosmological culture mentioned earlier. Also, it shows that Vesconte obviously harkened back to the work of the Minorite Friar, Fra Paolino, who was a Venetian, author of a treatise “De Mapa Mundi”.
Note; I do not think the dates allow for this last point and will proceed by time line as I started and indicate why later.
But, PDA Harvey in HOC 1/18, p314 clearly states; “the Vesconte Mappaemundi, together with the contemporary examples found in the chronicle compiled by the Franciscan Minorite Friar, Fra Paolino, clearly shows that influence of the Portolan Charts in three major characteristics.” I take contemporary to mean existing or happening at the same period and thus only logical thought on where the first gained the knowledge to draw such a mappa mundi will answer that question. It all depends on the training and when and where.
ChGEN/1/D10
The next cartographer is also a clergyman, Opicino de Canistris, (ChGEN/1/D10) c1296/1350, from Lomello who studied in Biella, Lomello, Bassignana and Pavia, and who learnt to “illuminate books” in Genoa where he stayed from 1316 to 1318. He was possibly acquainted with Petrus Vesconte as we do not have an accurate date for his travel to Venice. But, Opicino de Canistris wrote in 1335 whilst speaking of a scale of distances, that is to be found, “in mappa maris navigabilis secundum Januenses et Maioricenes”, i.e. “on the map of the navigable sea according to the Genoese and the Majorcans”, making the point for us that Majorca had become by 1335 a mapping centre. In 1320, he became Presbyter and from December 1323 he was in charge of the parish of Santa Maria Capella in Pavia. In 1329 he proceeded to Avignon where he drew three images of the world at different scales.
The next clergyman whose work is extant has been mentioned already, Fra paolino Minorata, c1275 to 1344 (ChGEN/1/D11 & D12), from Venice who wrote in his text “Chronologica Magna” a section entitled “de Mapa Mundi” and included a circular map some 248mm diameter of the known world, a planisphere in fact. The text could therefore contain this planisphere due to the work of Petrus Vesconte for Marin Sanudo which has been discussed earlier. Fra Paolino was sent to the Avignon court and Professor Marica Milanesi discusses this in the section page 19, heading, “La Cartografia Italiana nel medio evo e nel rinascimento” from the book, “La Cartografia Italiana, 1992.”
ChGEN/1/D11
In the book, Venice and Antiquity by Patricia Fortini Brown, page 55 has the following quote from Fra Paolino, De Mapa Mundi, 1321.
“I think that it is not just difficult but impossible without a world map to make (oneself) an image of, or even for the mind to grasp, what is said of the children and grandchildren of Noah and the four kingdoms and other nations and regions, both in divine and human writings. Nor wilt thou deem one sufficient without the other because painting without writing indicates regions or nations unclearly (and) writing without the aid of painting truly does not mark the boundaries of the provinces of a region in their various parts sufficiently (clearly) for them to be descried almost at a glance.”
ChGEN/1/D12
The following time line is given; Venice for the first 50 years of life but travelled in 1315 on two diplomatic missions. In 1326 he was Bishop of Pozzuoli and died in Naples c1344. We also know that a commission was set up by Pope John XXII to examine the text by Marino Sanuto and Fra Paolino was one of those chosen.
Patrick Gautier Dalche in his 2010 text, “Cartes, reflexion strategique et projets de croisade”, makes the following points;”Historiography has naturally hesitated between two explanations of this community of interests and works: either Marino Sanudo borrowed from Paolino, or it is the latter that inspired it. The chronology seems at first sight to oppose the hypothesis of Paolino’s influence on Marino Sanudo: the first manuscript of Chronologia magna seems to have been completed in 1323, and the Satyrica historia after 1334”
A footnote then states; “precise comparisons made by Simonsfield seem to show that Paolino would have used a version of Liber Secretum posterior to the presentation of 1321”
Therefore it would seem Petrus Vesconte was copied not vice versa!
The final cartographer that we are aware of to work in Genoa in the 14th century is Angelino Dalorto (ChGEN/1/D13). His extant work is dated 1325, but little else is known of his Genoese work. It is surmised that he travelled to Majorca shortly after that chart was drawn and became, but only because of the difference in language, “Angellino Dulcert” (ChDUL/1), a maker of nautical charts in the nation of the Majorcans in 1339”. Thus the Genoese period that we can determine as provable is restricted to probably 1330. But, the 1330 chart and the 1339 charts when superimposed, that is Dalorto on Dulcert, they match almost correctly, even with respect to the north western and northern coasts of Europe.
ChGEN/1/D13
Thus we can be certain of a migration from Genoa to Majorca of cartographers, for what reason though is not known, but hinted at by the lack of financial gain in Genoa.
And there this brief evaluation of early Genoese cartographers and their charts ends at c1330 as we have no extant information on others, until we read of Francesco Beccario who is in Barcelona. The dates for Him are 1400 and 1403 and thus we have a 50 or 70 year gap!
GENOESE CHARTS AND ATLASES OF THE 15TH CENTURY; SUMMATION
The following summary text is written chronologically as best adduced from the lifespan tables.
The first cartographer of this period is Francesco Beccario,(ChFB/1)(ChGEN/1/D14) born in Genoa, but travelled to Barcelona where he met Jehuda Cresques (Jaume Riba/Jacobus Ribes) and there worked on a commission for four charts. They completed two and then requested more funds for the next two to complete the project. This is rather a telling point as all through the history of Mediterranean cartography the exponents of the art appear to be underpaid, or have under-estimated the timescale required to draw and decorate the charts and thus their livelihoods were uncertain. All we know is that Francesco Beccario returned to Genoa via Savona, (just along the coast) where he produced a chart in 1403. It is thought he died by 1426AD.
ChGEN/1/D14
ChGEN/1/D15
The next cartographer is one Battista Beccario (ChFB/1)(ChGEN/1/D15 & D16) who produced at least two charts, one in 1426 and the other 1435. Battista Beccario was approached in 1426 to take on an apprentice, Raffaelino Sarzarna, of whom I will comment later. However after completing the 1435 chart it appears He departed for Majorca, c1438 when the apprenticeship was completed.
ChGEN/1/D16
I have included two Venetian Cartographers at this point as the first is a mariner who most certainly visited Genoa and was an accomplished cartographer, and the second a Friar/Monk who drew a fantastic planisphere aided by the first. They are included because of the obvious link of clergymen, but also because of the charts that were drawn which indicate both Genoese and Portuguese data being available.
ChGEN/1/D17
Andreas Biancho (ChAb/1)(ChGEN/1/D17) was both a Mariner- Comito de Gallia- and an accomplished cartographer completing an Atlas and charts whilst sailing from the Mediterranean Sea ports to Northern Europe and particularly London. His lifespan is c1400-1465 and thus he learnt both professions in his formative years, probably 1410-1420. In 1448 he drew His “Atlante Nautica Atlas” (ChAb/2) in London and hence must have taken on board the ship when it sailed from probably Venice, his patterns/templates in the knowledge that he would progress his expertise. He is thought to have been the assistant to Fra Mauro, Venice, who produced a fantastic Mappa Mundi in 1459 which is discussed later in chronological order.
ChGEN/1/D18
ChGEN/1/D19
We next meet Grazioso Benincasa, c1400/1482,(ChGEN/1/D18 & D19) a member of an Ancona family who was a mariner and prolific cartographer. We know of more than 25 charts produced but not necessarily where they were all drawn. He was certainly in Genoa from 1461 to 1466 but where he learnt the art is unknown as Ancona was not a hotbed of cartography in that period. We know he made a chart in Genoa dated 1461, that is now in the State archives in Florence, and it appears he was still active in the 1470’s.
The next cartographer, although we have no extant chart of his work is Agostino da Noli (ChCAN/1) Our knowledge of this cartographer comes from the records of the Republic of Genoa where in 1483 he asked to be exempted from all personal taxes and assessments on food and clothing for himself and his family for as long as he lived on the grounds that he was the only master of the craft of nautical cartography left in the city; this had already been granted to a master “ who….. makes guides for sailing that is, a manufacturer of compasses; for this craft, too, it seems that only one specialist had remained in Genoa). After calling himself very poor, Agostino alludes to the traditional importance of nautical cartography in the Ligurian capital, since “without these charts no one can sail anywhere, because it is they that furnish the sailors themselves with safe routes and point out ports” . The Doge acknowledged the charts’ importance and the fact that Agostino was poor, since he was unable to accumulate much money by the very laborious craft mentioned he therefore granted the requested exemptions, except for the consumption tax. The municipal offices then limited the exemptions to ten years and added a proviso that he should teach the craft to his brother.
Who his brother is, is open to question with some stating possibly Antonio da Noli (c1419-1466) who was also a mariner and discovered the Cape Verde Islands. But he HAD to leave Genoa under a cloud and went to Portugal. The records indicate Antonio’s brothers were Bartolomeo a Lawyer and Rafael, they do not mention Agostino.
COMMENT
If Agostino da Noli was the only exponent of the art in 1438, and Genoa was so concerned as to insist he trained his (unknown) brother in the art, it suggests that the preceding cartographer Battista Beccario was no longer in Genoa and had left for Majorca and his apprentice was not working for the , or in the Republic. It also suggests nobody had been trained in the art except Agostino da Noli in the preceding period and as the time-line indicates each cartographer trained and allowed his patterns/templates to be copied, or even handed them over to the next cartographer. Gaetano Ferro commented regarding Grazioso Benincasa and Genoese cartography being “alive”, and I find that fact very doubtful as it appears from the records to be just about surviving in the early 15th century, with Genoa being more interested in trade than Library charts.
We now discuss an enigma; an apprentice known by name but unknown. I can do no more than quote a paragraph from Gaetano Ferro as finding any other information has proven fruitless.
“Battista Beccario was certainly practising the craft of nautical cartography in Genoa in 1427, when he accepted as his “pupil and servant” ( as a document published and studied by Petti Balbi says) a nine year old boy, one Raffaelino, the son of a Genoese citizen by the name of Simone da Sarzana, navigator. The boy would have had eight years to learn “ the art of making charts and signs for sailing.” Hence it can be presumed that the master was in Genoa the year before this, and that the chart of 1426 cited above, must have been made in the city, whereas some uncertainty remains for the chart of 1435, since it is possible Beccario moved elsewhere”.
That information begs the question, “did Simone da Sarzana, navigator, have his son Raffaelino trained as a cartographer solely for the “art of making charts for sailing?”. Thus we do not read of his works as in all probability they were small cartographical sheets for sections of the Mediterranean Sea which “navigators” could purchase according to their sailing destinations. In other words, it was a private enterprise solely for the Sarzana family to exploit and did not concern the Republic, except for taxes! Thus if nobody else was involved it is unlikely another apprentice was trained.
ChGEN/1/D20
Moving on, the next cartographer Bartolomeo de Pareto was also a clergyman in Genoa. He drew a planisphere in 1455 (ChGEN/1/D20) and then became Provost of the church of San Giorgio in 1461. Therefore the strand running through the production of charts, atlases and planispheres does concern the Church and Monastic establishments who no doubt trained these clergy in the art of making a chart. It is attributed thus; “the priest Bartolomeo de Pareto of the city of Genoa, an acolyte of our most holy lord the pope, made this chart in 1455 in Genoa.” Gaetano Ferro makes the following comment, page 82; “This chart certainly has many elements similar to, or derived from, those of the 1435 chart, already mentioned, by Battista Beccario, and it should be compared to the anonymous Genoese world map of 1457; still the work of Ligurian hands, it could perhaps be the connecting link between these two documents.”
But before discussing the 1457 chart a slight deviation to Venice is required and the planisphere (ChGEN/1/D21) of Fra Mauro, a Camaldolese monk of San Michele, Murano. He produced one of the finest planispheres to exist today dated 1459, but as it must have taken several years to compose, or draw, it should be considered as at least 1457 to 1459 for research purposes.
ChGEN/1/D21
Considering it is 1950mm diameter, highly coloured and containing a myriad of toponyms and explanatory texts even that may be too little a period for its production. Obviously Fra Mauro required collecting many maps, charts and place lists as well as a copy of the works of Claudius Ptolemy and here we can see just how helpful Andreas Biancho with his wealth of experience would have been. It would be at least a 10 year period to amass the data. But the fact that there were two copies, one sent to Portugal probably indicates a far longer period or possibly the monastery of San Michele, Murano had a very active scriptorium and copyists were on hand to assist. Thus this could be a centre for cartographical training.
The “so called anonymous Genoese world map of 1457” (Cg1457 (ChGEN/1/D22) at least is dated although it is only thought to be made in Genoa. I have written a complete analytical paper on this planisphere, exploring its inner workings and commented upon its elliptical bordure which is in all probability a nod to Christian symbolism. It most certainly gave the cartographical draughtsman a problem as unfortunately it is mis-drawn and not symmetrical.
ChGEN/1/D22
I will draw your attention here to a separate text, ChWAF/1, which discusses Portolan Charts from 1413, 1436, 1448 and 1463/69 and explores the knowledge time lines.
ChGEN/1/D23
Albino de Canepa, (ChAC/1)(ChGEN/1/D23 & D24) a Genoese cartographer has bequeathed to us two extant charts; the first dated 1480 and the second 1489. A study of these charts has indicated their similarity to those produced in Majorca and hence we no doubt see a development line from the Battista Beccario charts of 1426 and 1435. This point will be fully explored later when the continuity development is examined.
ChGEN/1/D24
ChGEN/1/D25
But from Albino de Canepa, I believe sprang a dynasty of cartographers, the “Maggiolo Clan” who it appears were also “Notares” and thus probably had clientele on tap with the wherewithal to afford the library editions of Portolan Charts. For a single family to be able to produce so many for so long, even though they had monetary support from the Republic to commence with indicates a different business model and client base. The first of this clan, Vesconte Maggiolo (ChGEN/1/D25) was probably born c1470 and thus a student apprentice 1480/1490 matching the production period of Albino de Canepa. Vesconte de Maggiolo must then have set up his own atelier and produced charts because c1508 he is asked to go to Naples to produce charts for a “Corsican” family. The first extant work is an Atlas dated January 1511 which would have taken at least a year to complete, that is 1510 and thus the latest he would arrive in Naples is 1509.
(There is a separate paper in production covering the complete works by Vesconte de Maggiolo and therefore I will complete this section by merely stating he passed away in 1549.)
Finalising this summary of Genoese cartographers I must include Nicolo de Caverio; King-Hamy and G B Agnese. The first two are discussed at length in my various texts.
Nicolo de Caverio appears on the cartographic scene of Genoa as suddenly as he disappears from it. His family apparently lived in Genoa from 1488 to 1529 which my lifespan table accord with giving 1475 to 1540 with his single extant chart dated to c1502. It is a planisphere (ChGEN/1/D26) and the first from a Genoese to show the West Indies and include a scale of latitudes. Where he learnt the art and from whom is not known but the lifespan table and known dates indicate only Albino de Canepa, 1450/1515. It also indicates that Nicolo de Caverio may have been a contemporary of Vesconte de Maggiolo and could easily have learnt his art from both master Albino de Canepa and his first pupil, Vesconte de Maggiolo.
ChGEN/1/D26
The King-Hamy chart (ChGEN/1/D27) held by the Huntington library is both anonymous and undated. It is certainly Italian, but unproven Genoese. It has been dated to c1502 and is compared to other charts in the following text section for possible provenance etc.
ChGEN/1/D27
ChGEN/1/D28
Giovanni Battista Agnese (ChGEN/1/D28) was active from 1514 to 1564 and Gaetano Ferro has a simple paragraph for explanation as follows. “Battista Agnese— should be placed among the Genoese cartographers of this century (although the apprentices in his workshop may have continued producing maps even after the death of the master, using his models). He was the maker of a large number of maps and atlases, the latter containing as many as 32 and 36 plates. We know for a fact that he was born in Genoa, because some of his documents are signed, Baptista Agnese Januensis, but we do not know whether he received his training as a cartographer in the Ligurian capital (this is only a probability)”.
COMMENT
Thus I have trawled through the documented evidence, applied a simple but scientifically based age limit to each cartographer and indicated the distinct probability that it was a logical singular procession from Master to student=Master cartographer from c1300 to c1550AD. The time scale is correct, the overlap is correct with each and every Genoese cartographer requiring training in the complex art of cartography. For complex it is with many subjects to study to produce a Portolan chart and particularly to produce good quality Library editions of charts and atlases. But at all times I was cognisant of the background Monastic scriptorium which appears to be hovering unknown and unrecorded.
Now it is possible to follow the Genoese pattern/template through the centuries and establish the continuity or not of this Republics cartographers.
PART TWO OF THE TEXT
Throughout my website but on the “Charts” page particularly there are several papers which already indicate the Genoese Cartographical genre and compare the work of both Majorcan and Venetian cartographers. It is quite apparent that the Majorcan Portolan Chart industry owes much to the Genoese tradition and that will be fully examined in the next text to be written which covers Genoa, Majorca and Egypt; a separate text from a Maggiolo text.
The website pages which should be studied to understand fully the premise that the Genoese tradition is one of continuing training and the passing on of basic format information by way of copied patterns/templates from c1250 to c1550 are as follows explained here-in by their individual abstract sections, and are in the order they are to be found on the website.
ANDREAS BIANCHO DE VENERIIS ME FECIT M.CCCC.XXXvj: ATLANTE NAUTICO OF ANDREAS BIANCHO EXPLAINED
ABSTRACT
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.
There are 14 A4 pages and 29 A4 diagrams.
THE PTOLEMAIC INFLUENCE UPON ANDREAS BIANCHO; ATLANTE NAUTICO, 1436
ABSTRACT
The charts within ‘Atlante Nautico, 1436’, are all drawn upon the same size parchment, 260 x 380mm, which in all probability was produced as sheets measuring 262 x 393mm, 1 x 1 ½ Palmo and hence the measurement system of the charts can be assessed. The wind rose is constant upon each chart at 240mm which is thus 11 uncia, (the 262mm is 12 uncia, 1 Palmo). However the chart scales differ, but, they can all be shown to be drawn by the same hand, that of Andreas Biancho. However the last sheet, the Ptolemaic World map, although included in ‘Atlante Nautico’ may not be by Andreas Biancho, and thus its very individual form, its non-alignment to other similar maps is questioned.
This text is 9 A4 pages and 11 A4 diagrams
ABSTRACT
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
ABSTRACT
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.
There are 9 A4 pages of text and 26 (33) diagrams
CHARTS FROM 1300AD TO 1350AD COMPARED. IS THE RICCARDIANA MS 3827 THE MASTER TEMPLATE?
ABSTRACT
The conclusion to my text ChCs/1 was 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
ATELIER OF CRESQUES ABRAHAM OF MAJORCA CHART MS XII.D.102, NAPLES, ITALY ANALYSED
ABSTRACT
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 CARTA PISANA: BNF, Res. Ge. B1118 Amb. A FULL AND DETAILED EXAMINATION OF THE CHART
ABSTRACT
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 + 3 A4 diagrams.
MELANGE A TROIS AVEC L’UNE, MS 3827; CORTONA; VESCONTE 1311; DULCETO 1330
ABSTRACT
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.
10 DISTORTED CHARTS –LCN PROBLEMS CRITIQUES; HOC/1/19 p380-386 & LCP p 510/511
ABSTRACT
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, LCP, C2, INVESTIGATED AND THE BLACK SEA ENIGMA QUANTIFIED
ABSTRACT
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)
A. DULCETO, 1339 CHART (LCP C8) INVESTIGATED FOUR RESEARCH TEXTS ARE THEN ANALYSED
ABSTRACT
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.
PORTOLAN CHARTS OF 1413, 1436, 1448 & 1463/9; THEN CAPE VERT AND 3 LETTERS FROM 1495
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.
ABSTRACT
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 of 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
DIOGO HOMEN; LCP, A14 + 100 YEARS PORTUGUESE FLAWED EXPERTISE
ABSTRACT
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
1457 World Map; Genoese, Yes! Draughtsmanship before History
ABSTRACT
The planisphere known as the Genoese World Map, 1457, has no known author or actual place of production. It has been assumed by some researchers to be of Genoese origin, but this is contested. This text indicates from within the planisphere itself its point of origin and how it was constructed by melding a Portolan to the Ptolemaic Oikoumene.
The paper is 10 A4 pages and 15 A4 diagrams.
PART TWO TEXT CONTINUES
Thus having already made so many comparisons between charts this final section deals with the major players of the genre and indicates how their charts are close copies of a similar pattern/template and thus the charts are to be considered closely related but not copied.
1) Battista Beccario, 1435 chart
The chart is shown with the basic graticular latitudinal lines and a selection of longitudes only. It indicates that already explained in ChFb/1 and is compared as follows.
ChGEN/1/D29
2) Bartolomeo da Pareto, 1455 chart
ChGEN/1/D30,31,32
These three sheets interlink to form the whole chart and indicate the basic graticules for comparison to all others being analysed here-in. There is nothing surprising within those and this text is not the vehicle in which to discuss the excellence of the chart and its scope. The intent here is merely to illustrate the basic format of Genoese charts and thus perhaps confirm my belief that they all stem from one “training school”.
3) Comparison of Battista Beccario, 1435 and Bartolomeo da Pareto, 1455 charts.
ChGEN/1/D33,34,35
The three sheets, Diagrams ChGEN/1/D33, D34 & D35 have the two charts aligned at the Pillars of Hercules and to their wind rose graticule lines with the scale bars equivalent to each. The fact that I cannot draw much of the Battista Beccario coastline indicates one important point, that it is virtually identical to the Bartolemeo da Pareto coastal form in those situations of non drawing. Where there are red and black lines it indicates a minor deviation in the chart plot and “red ticks” have been used to illustrate the convergence. They are therefore to all intents and purposes one and the same chart for coastal profiles although 20 years apart for draughting.
4) Comparison of 1457 Genoese Chart to Bartolomeo da Pareto 1455 chart.
ChGEN/1/D36,37
This comparison as shown on Diagrams ChGEN/1/D36 & D37 is made only because of the Genoese connection. The 1457 chart is really much too small to compare adequately to the Bartolomeo da Pareto chart, but as they are so very close date-wise it is possible the Bartolomeo da Pareto chart was the instigator, being very large, to a smaller handier and perhaps different client base as its format indicates and is discussed in text Cg1457.
5) Albino de Canepa, 1480 chart
ChGEN/1/D38,39
Exhibiting many traits of previous charts it is a beautiful rendition of the Mediterranean basin and the Atlantic coast north to Scandinavia. There are obvious features copied from previous charts, but basically it is just a standard portolan.
6) Comparison of Albino de Canepa, 1480 to Bartolomeo da Pareto, 1455 Chart
ChGEN/1/D40,41,42
Again the closeness of the two charts, Diagrams ChGEN/1/D40, D41 & D42, which are some 25 years apart, clearly indicates a continuing use of a basic pro-forma which copied time and again will generate deformity in the pattern/template but retain all elements.
7) Albino de Canepa, 1489, Diagrams ChGEN/1/D43 & D44 compared to the 1480 chart
ChGEN/1/D43,44
Only nine years after the 1480 chart the 1489 chart still closely resembles it in both layout and style by visual examination. Therefore if we simply compare the two, as diagrams ChGEN/1/D45 and D46 indicate, we can see that the basic forma, a pattern or template has been used to provide the setting out onto which the detailed coastal profile is drawn and then the portolan chart adornment is added.
8) Vesconte de Maggiolo, 1512 chart
ChGEN/1/D47,48
This chart would appear to be incomplete in that the North West coast of Europe and the British Isles are not shown when there is more than adequate space on the parchment for their inclusion. The previous Atlas by Vesconte de Maggiolo, 1510/1511 has the British Isles and a World map with Scandinavia there-on, thus the Hispanic Society Portolan chart must be the working model for all of these that follow.
9) Comparison of Albino de Canepa, 1480 to Vesconte de Maggiolo 1512 chart.
ChGEN/1/D49,50
The diagrams ChGEN/1/D49 & D50 clearly indicate that the coastal profiles are taken from similar patterns/templates as they are in general agreement. The differences are the motifs and decoration which is to be expected based on a differing clientele.
10) Comparison of Albino de Canepa, 1489 and Vesconte de Maggiolo 1541 chart.
ChGEN/1/D51,52,53
These two charts are some 52 years apart in production, but a simple study of the three diagrams, ChGEN/1/D51, D52 & D53 clearly indicates that the original pattern/template is still being used to prepare the basic plot for the coastal form.
CONCLUSION
The intent of this research was to establish if it was possible for the extant Portolan Charts to be attributed to a continuity of both schooling and draughting practices in Genoa from c1200 to c1600 as their visual similarity appears to indicate.
I believe that this research indicates both a progression from cartographer to cartographer was clearly possible but also quite probable and that a continuity of the design work for a Portolan Chart was inherent in that training progression.
I also believe that many previous researchers have ignored the actuality of the time to draw a Portolan Chart or an Atlas and thus have conflated the historical record by dating charts without a rational timescale for their production. The Vesconte de Maggiolo Atlas drawn in Naples dated January 1511 would have taken all of 1510 to produce and had to be copied from a full chart to enable the parts to be properly aligned. Thus Vesconte de Maggiolo could only have travelled to Naples at the latest in 1509 and as I have surmised actually in 1508 taking a completed Portolan Chart with him which therefore must be dated to 1506/1507.
Thus I believe the dating of these and other works must be revisited as I have shown and a clearer picture of the actuality of chart production achieved there-by.
Michael J Ferrar December 2018