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This first part of the text, Leonardo da Vinci’s ideas of the world form, was intended as part of a previous text ChGEN/1, but that text was primarily about the development of Genoese charts and not included. The next text, ChGME/1 was not really applicable either, as it is primarily the development through Genoa to Majorca and the rest of the Mediterranean Sea area noted for Portolan charts. Thus it has become a standalone text and amplified to cover the whole subject and developments. It studies the main thrust of the L da V text but does not deal with items such as the height of rivers above the sea. L da V notes they fall constantly, and for his calculations at a Braccio per Mile, which in itself is acceptable but not if the length of the river, several hundreds of miles, is then transformed into several hundreds of Braccio; a good idea taken to the absolute extreme without the consequences being realised.
Thus I concentrate upon the facts written which can be sensibly evaluated.

The notebooks of Leonardo da Vinci contain a plethora of information which varies from the sublime to the ridiculous. We are told he was born in Vinci, to the west of Florence, 15/4/1452 and died in Amboise France, Chateau du Clous, 2/5/1559, having left Italy in 1516. Very little is known about his early life, his travels etc., through his 67 years, and the period 1482 to 1486 is a particular mystery. He trained in Florence under Verrocchio from the age of 14 and at the age of 20 was admitted to the guild of Artists and was set up by his father in his own workshop. But we do have proof of his Atelier in Milan and names of his “disciples”, and later copyists from the paintings they produced. It is also strange that he does not quote authorities for his facts and his observations as he states plainly in XIX Philosophy, No 987-991 that in all scientific research, his own experience should be the foundation of his statements.

But look at those statements and it is implausible that he saw/observed it all. However, in our research appertaining to his references to a Portolan Chart, “carta de navicare” we can be certain he studied one, but which one leaves us with no option but to assess what may have been available in either Milan or Florence as we do not know when or where he studied the “carta de navicare”. Logically it is between 1485 and 1510 that most of his notebooks were written, i.e. in his later life.

Text XIV; 937, Whether the Earth is less than the water.
Some assert that it is true that the earth, which is not covered by water is much less than that covered by water. But considering the size of 7000 miles in diameter which is that of the earth, we may conclude the water to be of small depth.

Text XIV; 940, Proves how the earth is not globular and not being globular cannot have a common centre.
We see the Nile come from Southern regions and traverse various provinces, running towards the North for a distance of 3000 miles and flow into the Mediterranean by the shores of Egypt; and if we will give to this a fall of 10 braccia a mile, as is usually allowed to the course of rivers in general, we shall find that the Nile must have its mouth ten miles lower than its source. Again, we see the Rhine, the Rhone and the Danube starting from German parts, almost the centre of Europe, having a course to the East, the other to the North, and the last to the Southern seas. And if you consider all this will see that the plains of Europe in their aggregate are much higher than the peaks of the maritime mountains; think then how much their tops must be above the sea shores.
Theory of the elevation of water within the mountains

Text XVII, IV, The Levant, The Levantine Sea, (1090)
On the shores of the Mediterranean 300 rivers flow, and 40, 200 ports. And this sea is 3000 miles long. Many times has the increase of its waters, heaped up by their backward flow and the blowing of the West winds, causes the overflow of the Nile and of the rivers which flow out through the Black Sea, having so much raised the seas that they have spread with vast floods over many countries. And these floods take place at the time when the sun melts the snows on the high mountains of Ethiopia that rise up into the cold regions of the air; and in the same way the approach of the sun acts on the mountains of Sarmatia in Asia and on those in Europe; so that the gathering together of these three things are, and always have been, the cause of tremendous floods; that is, the return flow of the sea with the West wind and melting of the snows. So every river will overflow in Syria, in Samaria, In Judea between Sinai and the Lebanon, and in the rest of Syria between the Lebanon and the Taurus mountains, and in Cilicia, in the Armenian mountains, and in Pamphilia and in Lycia within the hills, and in Egypt as far as the Atlas mountains. The gulf of Persia which was formerly a vast lake of the Tigris and discharged into the Indian Sea, has now worn away the mountains which formed its banks and laid them even with the level of the Indian Ocean. And if the Mediterranean had continued its flow through the gulf of Arabia, it would have done the same, that is to say, would have reduced the level of the Mediterranean to that of the Indian Sea.

Text XVII, The Red Sea, (1091. 1092)
For a long time the water of the Mediterranean flowed out through the Red Sea, which is 100 miles wide and 1500 long, and full of reefs; and it has worn away the sides of Mount Sinai, a fact which testifies, not to an inundation from the Indian Sea beating on these coasts, but to a deluge of water which carried with it all the rivers which abound round the Mediterranean, and besides this there is the reflux of the sea; and then, a cutting made to the west 3000 miles away from this place, Gibraltar was separated from Ceuta, which had been joined to it. And this passage was cut very low down, in the plains between Gibraltar and the ocean at the foot of the mountains, in the low part, aided by the hollowing out of some valleys made by certain rivers, which might have flowed here. Hercules came to open the sea to the westward and then the sea waters began to pour into the Western Ocean; and in consequence of this great fall, the Red Sea remained the higher; whence the water, abandoning its course here, ever after poured away through the Straits of Spain.

1092 (part only). The greatest river in our world is the Mediterranean river, which moves from the sources of the Nile to the Western Ocean. And its greatest height is in Outer Mauritania and it has a course of 10000 miles before it reunites with its ocean, the father of the waters. That is 3000 miles for the Mediterranean, 3000 for the Nile, as far as discovered and 3000 for the Nile which flows to the East, &c.

1095. The Tigris passes through Asia Minor and brings with it water of three lakes, one after the other of various elevation; the first being Munace and the middle Pallas and the lowest Triton. And the Nile again springs from three very high lakes in Ethiopia, and runs northwards towards the sea of Egypt with a course of 4000 miles, and by the shortest and straightest line it is 3000 miles. It is said that it issues from the Mountains of the Moon, and has various sources. The said lakes are about 4000 braccia above the surface of the sphere of water that is 1 mile and 1/3, giving to the Nile a fall of 1 braccia in every mile.

1106, Why water is found at the top of mountains.
From the straits of Gibraltar to the Don is 3500 miles, that is one mile and 1/6, giving a fall of one braccia in a mile to any water that moves gently. The Caspian Sea is a great deal higher; and none of the mountains of Europe rise a mile above the surface of our seas; therefore it might be said that the water which is on the summits of our mountains might come from the height of those seas, and of the rivers which flow into them, and which are still higher.

The Sea of Azov
1107, Hence it follows that the Sea of Azov is the highest part of the Mediterranean sea, being at a distance of 3500 miles from the strait of Gibraltar, as is shown by the “carta de navicare”; and it has 3500 braccia of descent, that is one mile and 1/6; therefore it is higher than any mountains which exist in the West.
The Dardanelles

1108, In the Bosphorus the Black Sea flows into the Aegean Sea, and the Aegean Sea never flows into it. This is because the Caspian, which is 400 miles to the east, with the rivers which pour into it, always flow through subterranean caves into the sea of Pontus; and the Don does the same as the Danube, so that the waters of the Pontus are always higher than those of the Aegean; for the higher always fall towards the lower, and never the lower towards the higher.

1109, The bridge of Pera at Constantinople, 40 braccia wide, 70 braccia high above the water, 600 braccia long; that is 400 over the sea and 200 on the land, thus making its own abutments
Central Asia

1111, Mounts Caucasus, Comedorum, and Paropemisidae are joined together between Bactria and India, and give birth to the River Oxus which takes its rise in these mountains and flows 500 miles to the North and as many to the West, and discharges its waters into the Caspiuan Sea; and is accompanied by the Oxus, Dargados, Arthamis, Xariaspes, Dargamaim, Ocus and Margus, all very large rivers. From the opposite side towards the South rises the great river Indus which sends its waters for 600 mioles Southwards and receives as tributaries in this course the rivers, Xaradrus, Hyphasis, Vadris, Vandabal Bislaspus to the East, Suastes and Coe to the West, uniting with these rivers, and with their waters it flows 800 miles to the West; then turning back by the Arbiti mountains makes an elbow and turns Southwards, where after about 100 miles finds the Indian Sea, in which it pours itself by seven branches. On the side of the same mountains rises the great Ganges, which flows southwards for 500 miles and to the Southwest a thousand … and Sarabas, Diarnuna, Soas and Scilo. Condranunda are its tributaries. It flows into the India Sea by many mouths.

These translations of texts can be further illustrated by the following texts which are illustrated by the original page and then the standard Italian translation;
Codex Leicester (gla’ Hammer); F 35v
Codex Atlantico; F311r
Manuscript F, 68v and 68r,
these codices are all readily available at Biblioteca Leonardiana; web site address is http://www.leonardodigitale.com

Firstly, it is necessary to establish the measurements that Leonardo could or would have used. He quotes the Braccia, basically the length of the arm and in Italy it varied considerably from place to place. The cities we are interested in, Florence and Milan are as follows;

Florence; Braccia = 2 palmo = 20 soldi = 60 quattrini = 240 denari = 583.6mm
The Palmo = 291.8mm and is the 1/8th part of the canne. The Canne or Perche of architects etc, = 5 braccia = 10 palmo = 2.918metres. The soldi is thus 29.18mm.
Milan; Braccia = 12 uncia = 594.9mm with an uncia thus 49.975mm. From the Braccia the soldi is 29.745mm. Milan also had a “foot” of 435.2mm.

There is also the Braccia Marine or the fathom in English.
From the extracts we can clearly accept that Leonardo da Vinci had in front of him at some time a “carta de navicare”, a Portolan Chart and from the toponyms and his later descriptions he has used a copy of “Geographike Hyphegesis” by Claudius Ptolemy and probably the maps drawn by Dominus Nicolas Germanus, who started in Padua and from 1451 to 1456 was at Ferrara, after which he moved to Florence and produced the Ulm edition in 1482. However, Francesco Rosselli of Florence may have been the engraver for the set of “new” maps in editions of Ptolemy’s Geographia, published in Florence in 1480-82. But, book 7, map 10 has the Asian information that is discussed by Leonardo illustrated here as diagram CgLdV/1/D01


The items like the River Nile could equally have been taken from a chart such as that by Mecia de Viladestes, 1413 Portolan chart, and texts such as Strabo or Pliny could equally have provided information. Without references it is perhaps unwise to speculate on these items of information and concentrate on the certainty. Thus we can use a Portolan chart to glean the other distance measures given. And here we have a large choice ranging from c1318 to 1489 as they are practically all the same chart, drawn from the same copied Pattern/Template as my texts ChGEN/1 and ChGME/1 adequately prove. I have therefore chosen the latest chart I have written about in the appendix to ChGME/1, that by Jac Bertran; it dates 1489 and was drawn on Majorca and is Diagram CgLdV/1/D02. If there are doubts that such a chart would have arrived in Milan/Florence, there is the Chart by Alberto de Canepa of 1489 drawn in Genoa which would equally have sufficed as the basic chart.


The measurements upon the chart CgLdV/1/D02 are direct in a straight line, as Leonardo da Vinci implies from his text; they are as follows; from the Strait of Gibraltar to the River Don is 3483 Miliaria, which is of course Leonardo’s 3500 miles and the length of the Mediterranean Sea is either, 3047 Miliaria in a straight line from Gibraltar to Gaza or 3170 along the putative 36N latitude and thus we can see that Leonardo da Vinci has chosen the horizontal measurement and concluded it is 3000Miles.

But of course that exercise leaves only one conclusion to be had, that the MILE of Leonardo da Vinci was in fact the Miliaria of the Medieval Cartographer which is 1.2326KM and 90 Miliaria make a degree of Latitude.

However when we come to the explanation of the diameter of the Earth given as 7000 miles we must pause and calculate from the known to the required answer of Leonardo da Vinci’s given figure. The world is 360 x 90 = 32400 Miliaria or in Roman Miles from which the Miliaria is derived and is 360 x 75 = 27000 Roman Miles. Thus the diameter of a circle of 32400M comprises PI x Diameter and is 32400 x 7/22 = 10309 Miliaria = 12707Km and thus 7000 x 1.8153KM. There is another nautical Mile used in the medieval period, the Miglia Marittimo which is 1 ½ Miliaria or 1.8489KM and a mere 2% difference, a minor change . It would therefore appear that Leonardo da Vinci appears to be “massaging” the figures to obtain simple whole numbers which are similar and thus easy to remember, that is 3500 and 7000.
Thus I can opine quite definitely that Leonardo da Vinci knew the nautical measurements used on Portolan charts and their basis in Roman Measurement of the Miglia, 1.4791Km which comprises 8 Stadia of 184.89 metres, whereas the Miliaria is 1.2326Km and comprises 6.667 Stadia. Thus the Miglia Marittimo has of course 10 stadia of 184.89 metres being 1.8489Km and derived from the Roman Mile as 1.25RM.

That was the basic text I would have included in either of my previous texts if in fact it had really fitted the subject matter. But it was in the end obvious it would require to be a stand-alone text to cover all of the items I have used as examples in the first section, ranging from Charts to Claudius Ptolemy etc. Thus an exploration concerning Leonardo da Vinci occurred.

This is now the second part of the Essay which develops the Leonardo da Vinci history and the new text I was asked to read entitled “America’s Birth Certificate”.

LEONARDO’S WHEREABOUTS IN HIS 67 YEARS; (timescale chart at end of text)
Born 15 April 1452, he was apprenticed to the artist Andrea di Cione, known as Verrochio at the age of 14 in 1466. Verrochio was the leading Florentine painter/sculptor and Leonardo was there for 7 years. In 1472 at the age of 20 he started his own workshop, but until 1478 there is little record of his whereabouts. It appears he left for Milan in 1482 and stayed basically there until 1499. But in 1485 he apparently received a commission from Hungary. This is possibly because Matthias Corvinus, King of Hungary married Beatrice of Naples and her brother is Duke of Calabria. It was possibly a Royal invitation to produce a painting from the Duke of Calabria’s knowledge of his works. However in 1499 he fled to Venice and in 1500 returned to Florence. He then went to Cesena in 1502 and returned again to Florence in 1503, but in 1506 returned to Milan. After the death of his father in 1504, he had to return to Florence in 1507 to act on his Father’s estate division, but in 1508 returned to Milan. From September 1513 to 1516 Leonardo lived in the Vatican, Rome and in 1516 entered the service of Francis 1st of France, dying in Amboise, 2nd May 1519. Thus it would appear that Milan held greater appeal than Florence for Leonardo.

Having nearly completed my ChGME/1 text, when I was asked to read this new text regarding Globes and Gores and particularly regarding a copper engraved Globe Gore set which was within this new text attributed to Leonardo da Vinci, and is the raison d’être for including it now in this text. I should add here that the NYPL which holds the copper engraving denotes it differently as this text explains later. I found it a fascinating exercise in research on part of the Geographic presentation of charts I had not previously thought to study as I prefer the technical aspect of a charts production. Thus I saw little to discuss in the construction of a globe, which I had noted as a simple geometric exercise from a set of gores and which to my eyes was a rather excellent way of producing a view of the known world in c1500, but, actually showed very little that a chart did not show other than its form.

However my interest was piqued when I read the sections as follows;
“3: This globular map is an anonymous, highly artistically decorated map, only known to exist in one single archetype, measuring 18.0cm by 36.0cm without date.”

This refers to the NYPL globular map gores which they attribute to Waldseemuller and date it to 1517. They state quite clearly “the extent of the engraving is 18 x 36cm” which means the gore size itself along the equator is much less than the 36cms quoted and hence fallacious figures are calculated within the text I am reading. (See notes at end on NYPL gores.)
“4: The Dimensioning of a globe (size of the gores on the globular map) in proportion with the diameter of the Earth43 as calculated by Leonardo da Vinci”.

As you can readily see I had already quantified the root diameter of the Earth by Leonardo da Vinci and thus decided to investigate this section in depth. Generally the Globes are made from 12 Gores of 30 degrees equatorial longitude and are a series of curved diamonds based upon the circumference chosen for the basic under-frame globe to which they will be applied, or if purchased as a plain wood cut the length of the equator will provide for the size of the under-globe. The six printed globular maps all have relatively the same circumference and thus diameter of approximately 110mm but varying from 110 to116mm, according to this research text I am reading. The diameter was being used to denote the size of the Globe which perturbed me as it is not as important as the equatorial dimension and hence the size of each gore. But alarm bells rang loud and clear when I read in a footnote (48) that “the nautical Mile in the Mediterranean Sea was c1.280KM”, a fact I knew to be so very wrong; it is 1.2326Km. I was even more perturbed when the 1.28Km was used with the 7000 mile diameter to produce world of 28149Km, “the imagined size of the Renaissance world”. The text went on as follows; “The diameter of the smaller world during Renaissance47 was calculated by someone who lived during this Renaissance in Tuscany and who wrote this down. The person I refer to is Leonardo da Vinci. The diameter of the Renaissance world as reported by Leonardo measured 7000 miles48.” This is absolute rubbish!!!

On reading this section I contacted the author and expressed my complete opposition to this thesis and stated why quite clearly with the examples from the foregoing text. We differed!

How it is possible for Leonardo da Vinci to state from Gibraltar to River Don is 3500 miles which by the charts scale bar gave that reading, and knowing that distance is some 45 longitudinal degrees, and then state the diameter of the world is 7000 of the same units is absolute balderdash. Leonardo may have “massaged” the figures lightly to arrive at a whole number as do many other mathematicians of the age given the lack of decimals, but to consider 90 degrees of longitude is equivalent to the world diameter is just nonsense for him to consider.

Returning to the Gores and other spurious measurements given I will set down the correct procedure and the possible measurements the makers could have used, but must remark upon the comment in that text which states, “The 11.2cm differs only 3.4% from 4 soldi or 11.6cm”. To put it plainly 112mm to 116mm is 4mm and a very noticeable distance, and 4 soldi is actually 116.72mm and thus nearer 5mm difference, an enormous amount. Then in note 51 we have “the Palmus Minor of 4 fingers and 6 fingers make 11,16cm”. If you read my text RmVt/2, diagram 4 sets down the actual words of Leonardo in translation, where he states it is Vitruvius ‘s measurements and 4 fingers make a palm and 4 palms make a foot. Hence 16 fingers or digitus make a foot, the Roman subdivision with each finger being 18.49mm and hence 6 digitus equals 110.938mm. Vitruvius was a Roman, not Florentine!

But more certainly, below the Vitruvian Man drawing is a single line subdivided with mirror text annotation “palmi” with the outer most subdivided by 4 and each are annotated “diti”.

The text I was asked to read clearly states that the diameters are basically 110mm and thus the equator is 345.7143mm and that equates to 14.02 uncia, which would mean each of the 12 gores was 1+ 1/6th uncia, and a quite manageable measurement.


However if we look to an actual example, we can utilize the Martin Waldseemuller 1507, wood cut as the diagram CgLdV/1/D03 illustrates and we are told produces a diameter of c110mm, and hence 345.7143mm equator. This wood-cut base was drawn at St Die en Vosges and then carved by a “so called” expert. Study the copy attached, (and the explanatory diagram CgLdV/1/D04 for construction methodology,) and note that it is only just acceptably accurate in its dimensions from the West to gore 6 then from 6 to 10 they are smaller than they should be, number 11 is correct and then the last, number 12 in the East is in fact much larger with a section attached to make up for the lost measurements. In St Die en Vosges, the standard measurement was a Pied of 10 pouce measuring 28.593mm. Divide 345.7145 by 12 and you have a gore size of 28.8095mm and as such we can consider they are one and the same with 12 gores of 28.593 having a diameter of 109.17mm; the difference in gore size is 0.2165mm and in diameter, 0.83mm. I think the woodcutter lost his way with the curves and thus I must comment that the wood engraver for the gores appears to be a rank amateur and probably ruined a well drawn original.

But the number of gores is critical for ease of draughtsmanship. If you have 12 gores of 30 degrees longitude each at the equator then the Pole to Pole distance is 6 gores, with three being either side of the equatorial line. Then each of the pole gores represents also 30 degrees of latitude and they are thus 30/60/90 degrees with the 60 degree line being a half gore width and thus a guide for the curved limit of each gore which has a radius of 9.25 gores or in the case of the Waldseemuller diagram also 9.25 pouce or inches (CgLdV/1/D04).


It is quite feasible to have gores of 22 ½ degrees, that is 16 number and thus 4 each side of the equator but with 22 ½ degree spacing, not an easy use for plotting the coastal outline. Of course it is possible to have many gore numbers provided they are all a definite whole section of the 360 degrees, but none are as easy to use as the 12 gores illustrated.

Then in section 9, I read “No other globular maps have the detailed numbered latitude notation on the interval line between 280-290 degrees east”, and this is supposed to be a major point that this NYPL globular chart cannot be Waldseemuller when he has drawn the same.

But I was quite concerned also by the dating of Globes and particularly that supposedly by Leonardo da Vinci. (The NYPL Globe Gore print will be analysed at the end of the text). I was aware that Leonardo had produced diagrams for octants as illustrated on Codex Atlanticus 923r and many other possible circular sections, but surprisingly the use of Gores to produce a globular chart was not amongst them. Several of his manuscripts incorporate geometric analysis of the sphere, and he is supposed to have drawn an octant world map now held in the Royal library at Windsor. But, this is also thought to be the work of one of his students from his sketches, and it is practically impossible to read as a map of the known world being so fragmented and in two sections of four.

The timescale for the production of an original to be copied by an engraver, if Leonardo had carried it out surely he would have investigated the geometry first?

Then as my professional life kicked in and I remembered visits to many Art Galleries and viewing the works of Leonardo da Vinci and his main atelier which was in Milan not Florence. I was aware of the Leonardo da Vinci painting “Salvatore Mundi” where he drew a glass Orb in the left hand and this mimicked a Globe. (Note, I now read that the Louvre experts doubt the attribution and deem it School of Leonardo!) Thus one of his students, Marco d’Oggiono c1500 drew his version of “Salvatore Mundi” with a Globe showing clearly a portrayal of the Mediterranean Sea, Africa and then the Ptolemy form for India etc. This is not the only copy of the “Salvatore Mundi” to feature a Globe. Hence it appears that Leonardo’s atelier either obtained a globe or perhaps, although doubtful, Leonardo had produced an earlier Globe than that being considered in the text I am using and failed to acknowledge it in his writings. The second copy is by Giampietrino who we know from Leonardo’s own text that he was one of his students, and the third by Gian Giacomo Caprotti, and I am including a print of each here for study purposes, as diagrams CgLdV/1/D05; CgLdV/1/D06 & CgLdv/1/D07.




However, if you study the paintings note that the parts of the world drawn there-on are not curved to the globe they are supposed to be drawn upon, but they are a flat map as per the illustrations in the Claudius Ptolemy “Geographike Hyphegesis” and thus would not have been taken from a globe, but are just representations. And, I cannot find any indication in the texts that Leonardo da Vinci made or considered making a globe. The closest I can get is the help he gave to fabricate the copper globe atop the dome of Florence Cathedral when he was apprenticed to Verrocchio’s workshop in 1471.

To illustrate that point, and concentrate on the period that the Globe Gore diagram held by NYPL, given in this new text as c1507 (but dated by them as 1517), following are the notes as penned for the Museo Galileo, Institute and Museum of the History of Science for the years 1506, 1507 and 1508.

1506; Leonardo annotates and rearranges, up to 1509, his studies on water, cosmology and astronomy in the Codex Hammer (formerly Leicester, now in the Bill Gates collection at Seattle, USA) and other studies on geometry, anatomy, the flight of birds, channelling, optics and architecture in the third part of Paris Ms.K, which includes folios 81-128 with notes datable at least up to 1508.

On April 27, in Milan, Giovanni Ambrogio de Predis reaches an agreement, also on behalf of Leonardo, with the Brotherhood of the Conception in regard to the second version of the Virgin of the Rocks.

In May there is correspondence between Alessandro Amadori, brother of Ser Piero’s first wife, and Isabella d’Este, concerning “those figures we had requested of Leonardo”.

On May 30, before leaving for Milan, Leonardo is obliged to commit himself by contract to returning to Florence within 3 months’ time, to finish the Battle of Anghiari.

On August 18 the Marshall of France asks the Florentine Signoria for an extension of time that will allow Leonardo to finish a number of works he has started in Milan. In October the Signoria protests. On December 16, Charles d’Amboise, praising the “egregious works”, insists on keeping Leonardo in Milan. Leonardo devotes himself to the funerary monument to Marshall Trivulzio, with a marble arch and bronze horse, and to designing the sets for Poliziano’s “Orpheus” with the ingenious invention of the “mountain that opens”.

1507; On January 12 the Florentine ambassador to the court of France, at Blois, informs the Signoria that Louis XII intends “to make use” of Leonardo, called “our dear and cherished painter and trusted engineer”.

In March Leonardo is in Florence with Salai. He conducts studies in anatomy in Santa Maria Nuova, draws the “Etruscan mausoleum”(Paris, Louvre) and musical instruments (Codex Arundel), in addition to taking note of Fra Giocondo’s hydraulic system at Blois (Ms K III). In Lombardy Leonardo meets his new pupil, Franceso Melzi.

He studies the course of the Adda and the surroundings of the villa of Charles d’Amboise; in Milan he carries out a project for a “garden of Wonders” at Saint Babila. In April he is given back his rights to the vineyard at San Vittore.

On July 26 Robertet, in the name of the King of France, urges the Florentine Signoria to intervene in favour of Leonardo, in his dispute with his brothers over his Uncle Francesco’s heredity. On September 7 Leonardo also requests the intervention of Cardinal Ippolito d’Este.

Lenardo goes to Florence and Charles d’Amboise writes to the Signoria asking them to allow the artist to return to Milan to finish a painting “most dear” to the King. The very young Pontormo, having been left an orphan, goes to Florence and spends a brief period in Leonardo’s shop.

1508; Leonardo notes in the Codex Arundel, on folio 79r, “Begun in Florence at the home of Piero di Braccio Martelli ( where he lives with the sculptor Rustici) on the day of March 22, 1508. This is a collection without order of many papers that I have copied here, intending to put them in order later”.

He then moves to Milan, where he lives in the parish of San Babila outside Porta Orientale, the East gate. He draws a bird’s-eye view of the city with a schematic map; elaborates projects for a church with central plan, conducts studies in compataive anatomy and compiles a treatise, now lost, on the anatomy of the horse.

His notes on painting from the lost Book A were later included by Franceso Melzi in the Codex Urbinate of the “Book on Painting”(Vatican Library). He designs water clocks and an automaton that marks the hours; compiles Ms F: “Begun in Milan on the day of September 12, 1508” including writings on astronomy, geology, hydraulics, the flight of birds, optocs, theory of shadows, studies for producing “mixtures” resembling plastic material, with references to Alberti and Vitruvius. Dating from the same period is Ms D with notes on optics and the physiology of the eye, also datable to 1509, which is related to Ms K3, Ms F and the folios of Windsor and the Codex Atlanticus. Both manuscripts are now in the Library of the Institut de France.

He paints two “Our Ladies” for Louis XII for which he receives 300 scudi and 200 Francs as salary from July 1508 to April 1509.

This is the most probable dating for the “Scapiliata”(The Girl with the Tousled Hair) in the Pinacoteca of Parma.

On August 18 he delegates De Predis to issue a receipt of payment for the “Vigin of the Rocks”, on condition that it will be possible to copy the painting, removing it from the Altar during the week.

That trawl through the texts and notes of Leonardo would surely have noted information concerning a globe, but nothing exists, and it is a comprehensive trawl, and the original drawing plus the copper engraving would have taken a rather long time.

However it must be noted that Martin Behaim produced his globe in 1492 and the anonymous Laon globe is dated to 1493, either of which would qualify for the painting model if it can be shown a copy was available in Milan.

But as I have postulated, we must consider that a globe was not in fact used to give the illustrations we have seen, but the artist has merely taken part of Claudius Ptolemy’s work and painted it on the “glass” globe to be seen as an up to date model. In other words no globe was required!

(As an aside, and completed much later, it is also worth noting that Vincenzo Coronelli produced a terrestrial globe of 110cm diameter, as opposed to the 110mm diameter we are discussing here; 10 times the size? And each gore 10 times the width, but the mathematics is the same.)

It is worth quoting in full the Galleria Borghese catalogue entry for the Marco d’Oggiono (c1475-1530), an oil panel 35 x 26cm.

“Portrayed as a young man, Christ is raising his right hand as a sign of blessing; in his left hand he holds a globe where the earth’s surface is represented according to the conventions of the period. The artist may have seen Henricus Martellus’s map (C1490) or that of the anonymous Lombard cartographer (1502), and he would certainly be aware of Leonardo’s demonstrating the sphericity of the earth (Sedini 1989). He was in fact a pupil of Leonardo’s during his final years of his first period in Milan. A gift from Pope Paul IV to Scipione Borghese, the painting, datable to c1500 entered the collection in 1611 where it was believed to be by Leonardo until Giovanni Morelli attributed it to Marco d’Oggino. In any case, it appears to be based upon an original painting by Leonardo, evidence for which includes an engraving dating from the mid 17th century and a copy that appeared on the Milan art market a few years ago.”

I have already written about the charts of Henricus Martellus and the work of Martin Waldseemuller in text ChHMWM/1 and although we are told perhaps a thousand copies of the Waldseemuller chart and the accompanying text were printed they appear to be after the events above and Henricus Martellus work being earlier and not a Portolan Chart would not therefore be in the frame as the “carta de navicare”.


From my research for the charts drawn in Majorca and their Genoese influence to their design as text ChGME/1 illustrates, I came across a text in the proceedings of the 3rd Geography Congress of Italy held in Florence 1898 and have used that within the text. However the second text, one I did not expect to find was headed, “Notizie in torno ad un mappamondo e ad un globo terrestre posseduto nel 1509 da Luigi Guicciardini”. It discusses the work of Conte di Ottomanno Freducci, one of my interests to be followed up as he worked in Ancona and travelled to Genoa, but the mention of a Globe held in 1509 and thus earlier in date for its manufacture, completely piqued my interest.

Copy of notes from the papers of the 3rd Geography Congress as original plus translation of the main text of each where necessary;

1) E. Casanova, La carta nautical di Conte di Ottomanno Freducci da Ancona…, pp. 8, 51, Firenze. Carnesecchi, 1894
2) La bottega di Alesandro di Francesco Rosselli merciaio e stampatore nella Miacellanea flor. Di erud. E storia, pubbl. Da I. dei. Badia, Vol II, pp 24-30, Firenze, Landi, 1894.

The inventory is dated 1528 but Rosselli died in 1525. He left in the shop, a very large number of cartographic and topographic maps, 37 in total between Globes and terrestrial globes of different species and dimensions. It may be thought that these globes were built by his father Francesco, illuminator, printer painter, cartographer and cosmographer. Francesco was born around 1445, died in the first 25 years of the 16th century, travelled to Hungary and settled in Venice. The accuracy and the different types of globes and globes are not specified in this inventory. A globe of F Rosselli was published in the second edition (1532) del suo Isolario da Bartolomeo da li Sonetti (Zamberti); fu unito poi ad alcuni esemplari dell’opera del Santerem, Essai sur l’histoire de la cosmographie et de la cartographic pendant le moyen-age, Parisi, 1849; e riportato ultimamente dal Berchet nella patre 3, vol II, della Raccolta Colombiana, pp 367, 394, 395. Il mappamondo che corrisponde perfettamenta a quello esposto nel nostro r. Archivio di Stato dal comm. Landau durante Il Terzo congress geografico, e ovale, a paralleli equidistant, e di grands bellezza, certo molto anterior al 1532. Cfr. M. Fiorini, Le protezioni delle carte geografiche, p597. Bologna, 1881; Sopra tre speciali proiezioni meridian e I mappamondi ovali del secc.XVI nelle Memorie della Societa geogr. It. ( e a parte), vol V, Roma, 1895, p26; G. Uzielli, La vita e I tempi di Paolo dal Pozzo Toscanelli, p524 e segg., Roma, 1894. >3) Ved. Il mio scritto Giuliano Vannelli Monaco fiorentino degli Olivetani costruttore epittore di sfere terrestri in Arte e Storia, anno XV, pp 57-61, 1896. Al Vannelli la Signoria florentina commise di restaurare e ridipingere un globo terrestre della Sala maggiore del Palazzo, ricompensandolo, poi, in seguito a parer del cancelliere Marcello Virgillio Adriani, con 56 florini d’oro. Si rileva incltre da una sua lettera del di 29 nov. 1524 che egli avea gia fatto, e stave facendo, diversi globi per I cardinal Salviati, Ridolfi e Rucellai. Di lui e di un’altra grande e bellissima sfera ch’egli avea costruita, si ha un cenno nelle “Historiae olivetanae, auctore D. Secundo Lancellotto per usino abate olivetano…” (Venezia, typ. Gueriliana, 1828, pp, XXII-362, (sotto l’anno 1518-20); “Floruit, Barnaba praesidente, Julianus Vannellus florentinus cosmographus, qui, inter caetera, magno artificio et labore, sphaeram mirae magnitudinis, quae in Bibliotheca Montis Oliveti hodie cernitur, aedificavit….”

The translation is as follows;

See my paper Guiliano Vannelli Monaco etc., To the Vannelli, the Florentine Signoria committed to restore and paint a terrestrial globe of the Palazzzo’s main hall (sale maggiore), rewarding him, following the opinion of the chancellor Marcello Virgillio Adriani, with 56 florins gold. It is also noted from his letter of November 29, 1521 that he had made, and was doing, several globes for the cardinals Salviati, Ridolfi and Rucellai. About him and another big and beautiful sphere that he had built, there is a short quotation in the Historiae Olivetanae, (here for Olivetans info; https://en.wikipedia.org/wiki/Olivetans) of author, D. Secundo (Secondo) Lancellotto (Lancellotti), Olivetans abbot from Perugia (perusino>Perugia).

The Latin text is as follows;
The Florentine cosmographer Giulano Vannelli flourished under the guide of Barnaba, he (Vannelli) among others, with commitment and diligence, built a sphere of considerable size that could be seen in the Library of Mount Oliveto …

Page 553 of the text has the following;
Nel 1509, dunque, Luigi, fratello di Franceso Guicciardini, lo storico (1), possedeva, oltre una piccolo sfera terrestre, una carta, o meglio mappamondo (2), in cui era rappresentata quella parte della terra, che va dall’ Aurea Chersonneso, o da Cattigara, fino all’estremita della terra ultimamente scoperta.

Note 2; Tale si puo dir veramente, giacche, sebbene l’Acciaiuoli non parli che d’un solo emisfero, sembra verosimile che in esso fossero indicate tutte le terre conosciute, e che non mancassero nella carta le altro. Ad ogni mode, il mondo intero conosciuto dovea essere almeno reppresentato nella piccolo sfera.

Quite frankly if any party really wishes to follow this line of research they should read all pages from 551 to 559 and the multitude of footnotes appended.

I have completed my general text which explores all of the possibilities regarding the globes and gores and now turn my attention to an analysis of the NYPL Gore Diagram.


This is the contentious diagram which is claimed to be by Leonardo da Vinci through the use of spurious distance measures and calculations as previously discussed.

I have redrawn the print for analysis as Diagram CgLdV/1/D08


To be clear, the NYPL, image ID 5047403, dates the print to 1517, names the author as Martin Waldseemuller and gives an “attributed name” as Louis Boulengier. Then under “dates/origin” they have “Date issued; 1517 (questionable); Place, Lyons; Publisher, Jean de la Place and “issuance”, monographic. The extent of the engraving is given as 18 x 36cm.
Therefore an analysis was carried out upon the print obtained from the NYPL Digital Collections site as follows:


The 760px copy provides adequate information for the analysis which immediately gave the actual Gore Size of 353 x 176.5mm and thus individual gores of 29.417mm. I have already noted that the Soldi (One twentieth of a Braccia) of Florence was 29.18mm and the Soldi of Milan 29.745mm which indicates that the 29.417 gore is in fact the nearly mid-point of the two measurements. The “inch” which was prevalent in the area of Lorraine where M Waldseemuller worked is 28.593mm. Given the plethora of differing measurements in Europe/Italy of the Medieval Age, varying by very little for the same unit I was not surprised to see this slight variation. But of course it means the diameter is actually 353 x 7/22 = 112.32mm for comparison purposes with other gores which are extant and approximately 110mm diameter.

But, this diagram is not for a Globular map to be constructed via the Gores, it is a highly decorated engraving which was meant to be cut to the 364 x 180mm bordure lines of the copper engraving and then merely rolled into a cylinder and glued together to form what is probably the first cylindrical map of the world. This could then stand on a desk, be rotated for each segment and would not require a mount or to be stopped rolling off!

Diagram CgLdV/1/D09 illustrates the drawing and the cylindrical map.



The word PLANO over-runs the actual gore size by the letter “N” being set from the Gore line to the right and the letter “O” following but inside the copper engraved border line.

Now study the left hand side and the minor over-run of the diagrams engraving. There is a single letter “O” perfectly aligned to the main text and obviously meant to be the last letter of the word PLANO when the cylinder is formed. Unfortunately the engraver did not place the “O” in the correct position; there should be an “N” adjacent to the line just on its right to be followed by the “O”, then a perfect overlap would be achieved when the whole is rolled to form a cylinder and glued correctly along the Gore line. To aid the formation of the cylinder the equatorial double line has been extended past the edge of the diagram such that it provides an alignment in the centre when the whole cylinder is formed. My photograph of the original sketch and the cylinder really says it all. The diagram was never intended as a globe but an artefact that when joined could as I have stated stand on a desk and be rotated for a view of each section of the world as it rotates daily and by moving it one gore at a time every two hours the cylinder keeps pace with the world rotation.

I consider this as probably an example of the cosmographical work carried out at St Die en Vosges in the early 1500’s where experimental projections were being developed. In the text I am criticising now, section 3 endeavours to move the author from M Waldseemuller to Donnus Nicholas Germanus Astrologus born c1420 and by 1507 would be 87 years of age, and that is unconvincing. If you study the letters so poorly engraved and thus indistinct on the right hand equator line (unfortunately you require to see the original in high resolution to appreciate the comment) and if in fact the first three letters are A B F then this would appear to be a variant of “Amico bene merenti fecit” and translates as “a friend, a benefactor made this”, and thus the following letters if they are D, S(possibly) G are perhaps the initials of the person who wrote this inscription, rather badly I would reiterate, or the initials of the Benefactor or the engraver. What they are not are the initials of the author of the gore diagram which an engraver has copied.

1) from the outset the size of the equatorial line for the gores has been wrongly identified in length. The overall engraved rectangle is actually 364 x 180mm and hence cannot be used to calculate the diameter as has been done in the text I am commenting upon.
2) The gore size is 353 x 176.5mm and hence each gore is 29.417mm.
3) The diagram was conceived as a “Cylindrical” artefact.
4) The “friend and Benefactor” is the important person in this investigation as the original drawing from which the engraver took his design is unknown and cannot be discerned from the engraving letters.
5) The diagram has engraved text which appears to be from the same genre as the Waldseemuller chart.

I suggest that a complete re-appraisal of the engraving is undertaken in the light of my findings, as the implication that it is possibly the forerunner of the cylindrical projections cannot be taken lightly. I also believe it indicates a dismissal of the text I was asked to read.


It appeared to me that these two Florentine scholars were in fact quite interlinked in their art and place of work during a part of their lives. Francesco Rosselli was obviously older and qualified much earlier than Leonardo and hence his work may well have been noted by both Verrochio and Leonardo. I found the coincidence of Francesco Rosselli being in Hungary at the court of Matthias Corvinus when Leonardo received his commission from the King intriguing and the fact that Rosselli not only assisted Contarini with a map but also produced the famed Oval map which was not the usual format. There were also town maps which may have inspired Leonardo. But it is all speculative and requires in depth research.



This is an essay of thoughts not a finished research paper as the time required to carry out a proper analysis is far in excess of the time I have available given the texts I have placed to one side to produce this essay.

The fact that the Gore diagrams are all roughly the same size I believe stems from the simple “inch” measurement that produces a sphere onto which the basic outline of the known world can be drawn. Anything larger requires much more information to be applied to the gores and in fact it exists already on the Portolan Charts and Mappa Mundi.

The “erdapfel” of Martin Behaim is one persons attempt to illustrate the world as it exists, globular, and thus I believe all we are witnessing is a band wagon effect of something rather simple to produce particularly if it is 12 gores of 30 degrees each.

The NYPL gore diagram is a variant to overcome the necessity for a globe to be made onto which the gores are applied. It serves exactly the same purpose and is in some ways more useful as an artefact than a globe. Decoration is everything, just look at the Majorcan Portolan Charts which stem from the Genoese charts, somewhat plainer. Can I sell many more prints of a cylindrical chart than a globular set of gores; surely a no brainer.


In the text HOC Volume 3, Part 1, chapter 6, Elly Dekker wrote concerning the globes made from 1300 until 1600 with an appendix, 6.1 which listed those known at the time of writing. But on page 150, figure 6.9 there is a surprising photograph, Cg LdV/1/D11.


Fig 6.9. J.C.Boulenger with globe. A drawing by a student of the Jesuit priest J.C.Boulenger, made during his lectures at Cleremont College at paris in 1588, viewing a globe and holding a pair of dividers. (Photo courtesy of BNF (Latin 10822, fol. 261v).

J C Boulenger 15?? – 1636, held the Chair of Mathematics at Clermont College, Paris, from 1607 to 1636. That under normal circumstances would give a birth date c1565.

The photographic copy is here appended and I draw your attention to the attributed name for the 1517 set of gores at NYPL: It is Louis Boulengier. But Olivier Cabaye in his paper “Un humaniste meconnu: Loys Boulengier d’Albi, mathematicien, cosmographe et geographe” in Revue historique CCCV/3, noted the following as a footnote;

Nous prenons ici le nom de ce personage retenu par l’ensemble des historiens. Ce n’est pas celui qui est le plus frequemment rencontre. On trouve d’autres orthographies: Boulonger, bolengier, Le Boulanger, Boulenger, Bolonger on Bolongic.

If we look at the probable life span of Louis Boulengier, he was on the last range of magistrates in 1506/1507, lived in Albi 1524 and is noted as deceased by two documents, one state’s 1545 and the other 1547. He was said to be long lived and if we allow 75 years he was born c1470.

Therefore we can be certain the two persons of similar name were not acquainted but it is quite possible J C Boulenger is the son of one of Louis Boulengier’s children and hence the continued attraction of Globes. Unfortunately documentation is very sparse on the family.

Finally I will deal with the date of the book in which the Gore diagram held by NYPL was found. It is fronted by a dedication as follows;

Reverendo in Christo Patri To the Reverend Father in Christ
et domino Jacobo Roberto albiensi and Seigneur Jaques Robertet, eveque d’Alb
dignissimo dominusque observandis- master extremely dignified and attentive
Ludivicus Boulonger Louis Boulengier

Jaques Robertet was Eveque d’Albi from 22nd November 1517 until 26th May 1518. But it appears there could be a hiccup in the transference of the Bishopric and in fact it could have occurred in 1514. But, quite frankly it is not 1507 and not Leonardo da Vinci carrying out the work.I think the coincidence of a Jesuit Priest with the same name, Boulenger/Boulengier and interested in Globes and thus cosmography gives reason to believe the family trait was from a humanistic stance to a definite mathematical, cosmographical and geography.

M J Ferrar, June 2019.