1434 (10 page)
Authors: Gavin Menzies
The Medici family spent 663,755 florins on patronage between 1434 and 1471. Recipients included Pope Eugenius IV, Toscanelli, Alberti, Poggio Bracciolini, Friar Mauro (for the world map of 1459), Christopher Columbus (described in chapter 10), and the young Amerigo Vespucci.
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The family supported Florentine humanists such as Toscanelli and Alberti, who showed a new approach to the world, explaining it through reason rather than mysticism. Cosimo financed artists who used perspective and proportion and scientists who argued that the earth was a globe, who could envision new lands full of riches that could be reached by sailing across the seas and never falling off the edge. He supported and financed scientists who could explain man's place in the universe.
Mary Hollingsworth cites Cosimo and his brother Lorenzo's embellishment of the sacristy at San Lorenzo as a notable insertion of science into the very heart of the church:
In the little dome above the altar, an astronomical fresco depicted the position of the sun, moon and stars for 6 July 1439, the official day of Union between the Eastern and Western Churches signed at the Council of Florenceâ¦. His choice of such an explicitly modern theme to commemorate this event was significant. Ceilings painted blue and studded with gold stars to represent Heaven were common in medieval churches. But this scientifically accurate depiction of a particular day's sky was unfamiliarâ¦.
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The position of the sun, moon, and stars for July 6, 1439, as seen in Florence may be checked by setting up the software package “Starry Night” for that day at latitude 43°48' N. The puzzling question is, how did Cosimo's artistâwithout the benefit of computer-based astronomical tablesâknow the position of the sun, moon, and stars for that day?
My first thought on seeing the painted heavens on the blue dome above the altar was that the artist must have had some sort of camera to photograph the sky so accurately. The mystery deepened after I studied color photographs of the dome, which displayed detailed celestial information.
Someone knew the precise positions of the stars relative to one another, as well as the positions of the sun and moon relative to each other and to the stars. Whoever painted that fresco understood the solar system. Author Patricia Fortini Brown, in “
Laetentur Caeli:
The
Council of Florence and the Astronomical Fresco in the Old Sacristy,” states: “This is not just another star-patterned vault: with its carefully defined celestial meridians and graduated band of the ecliptic, distinctly marked off in measured degrees, it represents a dated and located sky with apparent âscientific' exactitude.”
Canis Major as depicted in Alberti's night sky in the Sacristy of San Lorenzo.
As described in chapter 4, the apparent position of the stars relative to sun and earth changes daily over a 1,461-day cycle. Because of the astonishing accuracy of the fresco, it is possible to date the day in this cycle that the fresco represents. Brown explains:
The recent development of computer based astronomical tables which accord a degree of accuracy unavailable to Warburg's astronomer [a previous attempt at dating] now makes it possible to ascertain with certainty the date indicated by lunar and solar positions in the old Sacristy frescoâ¦. Professor John Heilbron has been able to verify independently the 6 July 1439 dating first mentioned by Bing and to fix the time of day at approximately 12 noon.
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At noon on July 6, 1439, a mass celebrated the triumph of Pope Eugenius IV, who, at the Council of Florence the day before, had sealed the union of the western and eastern Christian churches. (With the union achieved, Venice's navy subsequently defeated the Ottoman navy and lifted the blockade of Byzantium.) July 6 was named a public holiday, and the Cathedral of Santa Maria del Fiore was prepared with thrones for the Catholic and Orthodox bishops. Pope Eugenius IV celebrated a pontifical mass at noon with the epistle and gospel read in both Latin and Greek. The Decree of Union was then proclaimed in a papal bull, which began,
“Laetentur caeli,”
Let the heavens rejoice.
The dome was later painted to depict the moment of heavenly rejoicing. But how was it painted with such accuracy, and by whom?
My first thought was that the painting was done by observation of the sky. On examination, I realized this was impossible. It was broad daylight; although the stars were indeed in the positions revealed by the dome, they could not have been seen at noon.
What if the sky had been observed on the night of July 6, and the star positions extrapolated backward? This suggestion fails for two reasons. First, the fresco shows sun, moon, and stars, but the sun, of course, is not visible at night. Second, an army of observers would have been necessary to measure precisely the angles between stars and between the stars, sun, and moonâall at a time when the sun was not visible. Florence in 1439 had neither an army of qualified observers nor sufficient measuring instruments.
This complex painting required years to execute, during which the position of the stars relative to the earth would have changed according to the 1,461-day cycle. Thus it could not have resulted from piecemeal observations over the course of the job. Instead, the inescapable conclusion is that the artist had access to accurate astronomical tables.
From the financial accounts (quoted by James Beck, listing payments to the artists in
Leon Battista Alberti and the Night Sky at Sun Lorenzo
),
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it appears that the painting was started after the death of Giovanni and his wife, Piccarda Bueri, in April 1433, possibly halted during the Medicis' exile (October 1433âOctober 1434) and started again in 1435, later payments being made in May 1439 and January and
September 1440. The painting thus took at least six years. The explanation for the astonishingly accurate dating seems to me that the constellations with their figures (the major part of the work) were painted over six years up until the Union of the Churches, after which specific stars were painted in positions they would have occupied at noon on July 6, 1439âa relatively minor and easy piece of work if the declination and right ascensions of the stars were known.
Beck, has shown that the painter was Leon Battista Alberti, perhaps assisted by his friend Paolo Toscanelli. These two were Florence's leading astronomers and mathematicians in 1439. Alberti in 1434 had accompanied Eugenius IV to Florence, where he met Toscanelli.
As we shall shortly discover, the most likely explanation of the fresco mystery is that Alberti, who served as the pope's notary, met the Chinese delegates and obtained a copy of the astronomical calendar presented by the Chinese to Eugenius IV. The calendar provided the necessary information of right ascensions and declinations of stars to draw the night sky for a particular day and hour.
H
ere is a translation of Paolo Toscanelli's letter, written in Florence on June 25, 1474, to Canon Fernan Martins (Martinez de Roriz), King Alfonso of Portugal's confessor at the court in Lisbon.
Canon of Lisbon, Paulus the physician [i.e. Toscanelli] It pleased me to hear of your intimacy and friendship with your great and powerful King. Often before I have spoken of the sea route from here to India, the land of spices: a route which is shorter than that via Guinea. You tell me that His Highness wishes me to explain this in greater detail so that it will be easier to understand and take this route. Although I could show this on a globe representing the earth, I have decided to do it more simply and clearly by demonstrating the way on a nautical chart. I therefore send His Majesty a chart drawn by my own hand, on which I have indicated the western coast line from Ireland in the north to the end of Guinea, and the islands which lie upon this path. Opposite them, directly to the west, I have indicated the beginning of India [i.e., China, using the nomenclature of the 15th century], together with the islands and places you will come to: how far you should keep from the Arctic pole and the equator; and how many leagues you must cover before you come to these places, which are most rich in all kinds of spices, gems and precious stones. And be not amazed when I say that spices grow in lands to the West, even though we usually say to the East: for he who sails west will always find these lands, in the west and he who travels east by land will always find the same lands in the east.
The upright lines on this chart show the distance from east to west, whereas the cross lines show the distance from north to south. The chart also indicates various places in India which may be reached if one meets with a storm or head wind or any other misfortune.
That you may know as much about these places as possible, you should know that the only people living on any of these islands are merchants who trade there.
There are said to be as many ships, mariners and goods there as in the rest of the world put together especially in the principal port called Zaiton where they load and unload one hundred great ships of pepper every year, not to mention many other ships with other spices. That country has many inhabitants, provinces, kingdoms and innumerable cities all of which are ruled by a prince known as the Grand Khan, which in our language means “The King of Kings,” who mainly resides in the Province of Cathay. His forefathers greatly desired to make contact with the Christian world, and some two hundred years ago they sent ambassadors to the Pope, asking him to send them many learned men who could instruct them in our faith; but these ambassadors [the Polos] met with difficulties on the way, and had to turn back without reaching Rome. In the days of Pope Eugenius [1431â1447], there came an ambassador to him, who told him of their great feelings of friendship to all the Christians, and I had a long conversation with the ambassador about many things: about the vast size of the royal buildings, about the amazing length and breadth of their rivers, and about the great number of cities on their banksâso great a number that along one river there were two hundred cities with very long, wide bridges of marble that were adorned with many pillars. This country is richer than any other yet discovered, not only could it provide great profit and many valuable things, but also possesses gold and silver and precious stones and all kinds of spice in large quantitiesâthings which do not reach our countries at present. And there are also many scholars, philosophers, astronomers, and other men skilled in the natural sciences who govern that great kingdom and conduct its wars.
From the city of Lisbon to the west, the chart shows twenty-six sections, of two hundred and fifty miles eachâaltogether nearly one-third of the earth's circumference before reaching the very large and magnificent city of Kinsai. This city is approximately one hundred miles in circumference and possesses
ten marble bridges and its name means “the Heavenly City” in our language. Amazing things have been related about its vast buildings, its artistic treasures, and its revenues. It lies in the Province of Manji, near the Province of Cathay, where the King chiefly resides. And from the island of Antillia which you call “the Island of the Seven Cities,” to the very famous island Cipangu are ten sections, that is, two thousand five hundred miles. That island [Cipangu] is very rich in gold, pearls and precious stones and its temples and palaces are covered in gold. But since the route to this place is not yet known, all these things remain hidden and secret; and yet one may go there in great safety.
I could still tell of many other things, but as I have already told you of them in person, and as you are a man of good judgement I will dilate no further on this subject. I try to answer your questions as well as the lack of time and my work [would] have permitted me, but I am always prepared to serve His Highness and answer his questions at greater length should he so wish.
Written in Florence on the twenty-fifth of June 1474
.
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Pope Eugenius IV was born Gabriele Condulmer in 1383 in Venice.
2
He was pope from March 3, 1431, until his death on February 23, 1447. His mother's side was a rich merchant family, the Corrers, whose magnificent palaces can be seen alongside the Grand Canal in Venice to this day.
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He was crowned pope at Saint Peter's in Rome on March 11, 1431. After June 1434, he spent his pontificate in Florence until he moved to Ferrara in 1438.
A short while after his letter to Canon Martins, Toscanelli wrote to Christopher Columbus:
Paul, the Physician to Christopher Columbus, greeting. I received your letters with the things you sent me, and with them received great satisfaction. I perceive your magnificent and grand desire to navigate from parts of the East to the West [i.e., to sail westward to China] in the way that was set forth in the letter that I sent you [a copy of the letter to Canon Martinez] and which will be demonstrated better on a round sphere. It pleases me much that I should be well understood: for the voyage is not only possible it is true, and certain to be honourable and to yield incalculable profit, and a very great fame among all Christians. But you cannot know this perfectly save through experience and
practice as I have had in the form of the most copious and good and true information from distinguished men of great learning who have come here in the Court of Rome [i.e., Florence at that time] from the said parts [China] and from others being merchants, who have had business for a long time in those parts, men of high authority. Thus when that voyage shall be made it will be to powerful kingdoms and cities and most noble provinces, very rich in all manner of things in great abundance and very necessary to us, such as all sorts of spices in great quantity and jewels in greatest abundance.
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In these two letters Toscanelli tells Canon Martins and Christopher Columbus that the earth is a sphere and that China can be reached by sailing west from Spain. Toscanelli writes that Eugenius IV received an ambassador from China and that he, Toscanelli, obtained this information from him and from men of great learning who came to Florence in the time of Eugenius IV (1434 or later).
Yet in 1474, when Toscanelli wrote these letters, Europeans had not reached southern Africa, and it was another eighteen years before Columbus set sail for the Americas. So how did Toscanelli know China could be reached, not only via the east around Africa, but via the west?
Toscanelli's claims to Columbus about the map or globe seem extraordinary.
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He asserts that the chart shows that the distance, sailing westward, from Lisbon to Kinsai in China is only one-third of the earth's circumference and that from Antilia (Island of the Seven Cities) to the “very famous island Cipangu” is a distance of 2,500 miles. He implies in his letter to Columbus that the information is on a round sphere and that the lands of spices can be reached by sailing westward.
The famous island Cipangu is Japan. So Toscanelli's claim that it is only 2,500 miles from Japan to Antilia, in the Caribbean, seems absurd. So does his claim that the map shows the distance from Lisbon westward to China is one-third of the earth's circumference; in fact, it is nearer two-thirds. If Toscanelli's account is true, it must have been a very distinctive map.
I have searched for this map for twelve years, starting with an investigation into the maps of Toscanelli's friend Regiomontanus. As described in later chapters, Regiomontanus worked closely with Toscanelli. Some
historians, notably Ernst Zinner, the leading authority on Regiomontanus, and Gustavo Uzielli, believe the map Toscanelli sent to Columbus was drawn up with help from Regiomontanus.
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Here is Zinner:
Toscanelli was famous for his 1474 letters to Columbus and Canon Martins in which he advised them about reaching the Indies by crossing the world ocean and suggested a map for the journey. It is possible that there was a prototype of this map in one of Bessarions's nautical charts which contained islands similar to those found by Columbus; this was reported by Marco Parenti in March 1493. Now Bessarion [backer of Regiomontanus and friend of the pope] died in 1472, so Uzielli who described Toscanelli's work took the position that the map had been designed by Regiomontanus with Toscanelli's assistance. Such a collaborative work is not impossible forâ¦the two men were in correspondence.
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At first this seemed a fruitful line of enquiry. In 1471, Regiomontanus received permission to make Nuremberg his home, and the next year he set up a printing press to print documents. In 1472 he stated his intention to publish maps: “
et fiet descriptio totius habilitatis note quam vulgo appellant Mappam Mund Ceteru germanie particularis tabula; ite Itali; Hispanie: gallie universe; Greciq.
” (My translation: “to make a description of the entire habitable world commonly called a mappa mundi. Germany is described in detail, likewise Italy, Spain, Gaul, and Greece.”)
For the next three years Regiomontanus was preoccupied with ephemeris tables and calendars. In 1475 the pope summoned him to Rome, where Regiomontanus died, probably of the plague. He never got around to publishing his world map. Zinner, in his lengthy book on Regiomontanus, does not mention publication of a world map. So that line of enquiry ended in a cul-de-sac.
Then, out of the blue, in April 2007 I received an e-mail from Mr. A. G. Self, a friend of our website, who attached ten pages from a book on Magellan by F. H. H. Guillemard.
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In the book, Guillemard exhibited globes that Johannes Schöner published in 1515 and 1520.
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The author wished to demonstrate that before Magellan set sail, European globes had been published showing
the strait leading from the Atlantic to the Pacific, which we now call the Strait of Magellan. The globes also showed the Pacific and China. The authenticity of Schöner's globes of 1515, 1520, and 1523 has never been challenged.
I studied Schöner's 1515 globe with the greatest interest. It was virtually identical to the copy of a globe shown on Waldseemüller's 1507 world map. Both are shown in the second color insert of this book.
Then the lightning bolt struck. Schöner's 1515 globe corresponded exactly with the description of the globe in the letters Toscanelli sent to the king of Portugal and Columbus. It is as if Toscanelli had Schöner's globe in front of him when writing the letters. Below I have quoted Toscanelli (Q) and followed with my remarks (R). Please have Schöner's globes to hand.
- Q: “Often before I have spoken of the sea route from here to India, the land of spices, a route which is shorter than that of Guinea.” R: This is what Schöner's 1515 and 1520 globes show.
- Q: “Although I could show this on a globe representing the earth, I have decided to do it more simply and clearly by demonstrating the map on a nautical chart [i.e., Toscanelli, like Schöner, is copying from a globe, putting the copy on a chart].”
- Q: “I therefore send His Majesty a chart drawn by my own hand.”
R: Schöner's 1515 and 1520 maps (or charts) are copies of a globe. - Q: “on which I have included the western coast line from Ireland in the north to the end of Guinea, and the islands which lie upon this path.”
R: This part is shown on the 1515 globe's eastern hemisphere. - Q: “Opposite them, directed to the west, I have included the beginning of India.”
R: China is shown as “India,” “India Superior,” and “India Meridconalis” by Schöner. - Q: “The upright lines on this chart show the distance from east
to west, whereas the cross lines show the distance from north to south.”
R: There are more upright and cross lines on Schöner's 1520 globe, but both of Schöner's have these. - Q: “From the City of Lisbon to the west, the chart shows 26 sections of 250 miles [6,500 miles] eachâaltogether nearly one third of the earth's circumference before reaching the very large and magnificent city of Kinsai.”
R: The Canaries (Fortunate Islands) are shown 120 degrees east of Quisaya [Kinsai]; therefore Lisbon is 125 degrees from Quisaya, approximately one-third of the earth's circumference (earth's circumference is 360 Ã 60 miles, viz 21,600 miles; one-third is 7,200 miles). - Q: “It [Kinsai] lies in the Province of Manji.”
R: Quisaya is shown in Manji province by Schöner. - Q: “near the Province of Cathay.”
R: This is what the 1515 globe shows: “Quisaya Manji which is shown in Manji province and shown above Manji is “Chatay” [Cathay]. - Q: “and from the island of Antilia which you call âthe Island of the Seven Cities,' to the very famous island of Cipangu are ten sections, that is, two thousand five hundred miles.”
R: Antilia is shown on the 1520 chart at 335° and Zipangu at 265°, a difference of 120 degrees, which at latitude 15° N is approximately 2,500 miles (one-third of earth's circumference at that latitude).