The Newberry Sfera and the Study of Renaissance Geography
Raymond Clemens

Much contemporary research on Renaissance cartography has centered around European exploration and the mapping of the new world. The graphic knowledge conveyed by increasingly detailed and accurate maps is a seductive pleasure that delights historians and confirms assumptions about western culture and its place in the world. Medieval maps are, by contrast, not exclusively a representation of the “real” world; they combine geographical with historical and theological knowledge. Medieval mappamundi explain man’s place in the cosmos and his role in salvation history from the fall of Adam and Eve to the apocalyptic last days. Between these extremes are the encyclopedic maps of Macrobius and Isidore; these represent in schematic format what was believed to be the actual earth’s surface as it was then understood, often with mythical but rarely theological dimensions. Dati’s Sfera, written before 1435, draws on all three traditions. The Sfera was a didactic text, designed for self-instruction in astronomy and geography, and as such, it provides a window on the world as the merchant class of Florence understood, lived, and traveled in it.

The Newberry possesses a beautifully illustrated manuscript copy of the Sfera with a complete set of illuminations. The text of the Sfera dates from sometime before 1435, when its author, Gregorio Dati, died. A Florentine merchant who rose from humble beginnings as the grandson of a purse vender to a position of prominence in the city council, Gregorio Dati (1362-1435) was eventually appointed Standard Bearer of Justice, the highest civic office in Florence, in 1429. Some manuscripts of the Sfera attribute the work to Gregorio’s brother Leonardo (1360-1425), a Dominican friar who became master general of his order, but most scholars agree this is a false attribution. Although Leonardo was well known as an author of sermons and commentaries on Aristotle, what survives of his works is written in Latin. In addition to the Sfera, Gregorio is also the author of the History of Florence 1380-1406, a chronicle of Florence’s war with Giangaleazzo Visconti, the despotic Duke of Milan (1351-1402), written in Italian. We also know a great deal about Gregorio’s life from a register he kept (a ricordanze) in which he recorded various business and personal information. This was a common practice in Renaissance Florence. Such books, called libri segreti (secret books) to distinguish them from official business registers, were often beautifully bound in brilliantly dyed leather covers color coded to distinguish the public from the private and various years and business ventures. In his ricordanze, Dati describes his business ventures as a silk merchant with extensive international contacts who often traveled across the western Mediterranean to conduct business in Spain. After the death of his first wife in 1390, he lived in Valencia for two years, where he sired a son with a Tartar slave named Maria. His sent his son, whom he named Thomas, back to Florence.

The journal reveals that in 1393, Gregorio set out for Valencia again but was set upon by pirates from Briganzone near the Riviera (outside of Genoa). He lost personal assets including pearls, merchandise and clothing valued at 250 florins and company merchandise valued at 300 florins. He alluded to this event and to the perils of sea travel in general in his Sfera, where he wrote:

And with a chart on which are marked the winds and ports and all the coastlines, merchants and pirates sail the sea—one for profit, the other for plunder. And in an instant the rich and unlucky know, sometimes in the evening and sometimes in the morning, that Fortune in any other thing does not show herself so ruinous.

At the end of his ricordanze, we learn that Gregorio had twenty children, ten boys and ten girls, by three different wives; each of his wives and all but five of his children had predeceased him by 1427, the last year Gregorio recorded his affairs in the ledger. That Gregorio had an interest in education is clear from his Florentine history, which describes the development of the city’s unique governing structure in great detail. The Sfera was yet another way to communicate vital information about the world outside of Florence to his fellow citizens.

The Sfera opens with a discussion of the cosmos; Dati’s text and diagrams represent the traditional earth-centered view of the universe common in the early fifteenth century (see Figure 2). Once man’s place in the cosmos is established, Dati turns to discuss various astrological phenomena such as solar and lunar eclipses. Dati adopted the common encyclopedic technique of placing diagrams in the margins of his work to explicate the text and to serve as an aide-memoire (see Figure 3). Dati was the first to refer to Isidore’s world map as a T-O map, and his verses assisted the student in committing this description to memory:

The drawing of a T inside an O shows how the world was divided into three parts, and the upper and larger realm, which takes almost half the circle, is called Asia; the straight leg, the sign that separates the third name from the second, separates Africa from Europe. The Mediterranean Sea appears in the middle between them [that is, the stem of the T].

Dati’s T-O map (Figure 3), following Isidore’s example, neatly divides the continents into three parts; his non-schematic map found directly under the Isidorian map, more realistically portrays the same division of the continents. One can easily make out the boot of Italy at the center of the Mediterranean and the Arabian peninsula separated from Africa by the Nile. If Dati incorporated Isidore’s diagram because it was a useful didactic tool, he also wanted his readers to know that the diagram didn’t represent the actual shapes and relationships of the land masses. The astronomical and cosmological part of Dati’s book have excited little interest and little research, despite the fact that his work was the first in western Europe designed to convey such information, often beleived to be unnecessary or even dangerous, to the “common man.”

In the last part of the Sfera, Dati treats lands around the southern and southeastern Mediterranean. Here Dati employs two different types of maps. His maps of Jerusalem and the Holy Land (see Figure 1) seem to draw on the Ptolemaic tradition of map making, which is possible as Ptolemy’s Geography was translated into Latin between 1406 and 1409 by Jacopo Angeli da Scarperia, and maps based on his translation appeared within twenty years, well before the Dati’s death in 1435. Without ports, rhumb lines, or roads, Dati’s map of the Holy Land would not have been useful for physical travel. Instead, his goal may have been to provide a graphic context for the people, places, and events in Biblical and ancient history. Roger Bacon, justifying the study of geography and the making of maps in his Opus Maius (c. 1268), writes:

. . . if one does not understand the physical form of the world, history is apt to become a stale and tasteless crust. . . But if he can picture to himself what the places named [in scripture] are like, and has learned their positions, their distances [from each other], their distance up or down, their longitude and latitude. . . then the letter of history will fill him with pleasure, and he can easily and confidently advance to a realization of its spiritual sense. (trans. Herbert Howe).

Dati’s map illustrates the major cities in the Holy Land, the historically significant waterways, mountain ranges and their relative relationship to each other. Like his earlier maps, Dati’s maps of the Holy Land have not been extensively studied.

What has attracted the historian’s attention has been Dati’s unique use of portolan charts in the last quarter of the work. Portolan maps largely fall into two categories: actual charts used to navigate the Mediterranean, Black Sea and the eastern Atlantic, the utilitarian function of which is manifest, when the maps survive at all, in their often worn condition; and at the opposite extreme, display copies, such as the Lopes Atlas, produced to display the power of the Portuguese empire in the sixteenth century. Dati was the only cartographer in the Renaissance to fragment portolan maps and press them into the service in an educational primer. His use of the portolan maps indicates his intention of providing the most up-to-date and accurate maps then available for his primary audience: Florentine merchants. Historians in the early part of the twentieth century dismissed Dati’s work because the charts did not demonstrate new knowledge (they only represent the coast of Africa as far south as the Canary or Fortunate Islands, information available from 1336), and they were not particularly good portolan maps—there are no rhumb lines, making them useless for navigation, and because they are fragmented, there is no path across the Mediterranean—the maps are useful only for those skirting along the shorelines. What Dati does provide, however, is the information necessary not for sailors but for merchants and traders—the distance between major trading ports and their location relative to each other.

Despite their fragmentation and their clearly didactic intention, there is no question that Dati’s maps are aesthetically appealing. The artist who copied the Newberry Sfera made creative use of the images by extending the shores of the Mediterranean into the the text itself so that the words form little islands. In his map of the Holy Land (see Figure 1), the Caspian Sea engulfs the end of the second and the entire third stanza. The Tigris and Euphrates radiate from the mountains, with the region of Mesopotamia between them. Babylon is identified by the tower of Babel (here illustrated by a pillar), and Mecca is shown as a stone box in Arabia. Noah’s ark is shown as a wooden house at the top of the Caucasus mountains, just to the right of the crease in the center of the manuscript. Depth has been indicated by color, and movement is portrayed by wavy lines that radiate out from the coast. His map of Fez and the Canary Islands is equally striking (see Figure 4). Here the text is the Mediterrenean with the coast of Africa jutting into the text. The map follows the coast to the Fortunate Islands before it reaches the end of the known world and the end of the page.

The Newberry’s Sfera is an early copy of this significant work. There is a coat of arms, as yet unidentified, on the front page of the work, indicating that this manuscript was copied for a particular individual. Based on an examination of the codex, we can be sure that the Newberry Sfera was composed in the manner typical for the fifteenth century: the text was copied first, followed by the initial letters in blue; then the marginal summaries were written, and finally the vinestem illumination and maps themselves were drawn. The Newberry Sfera is creased down the middle, indicating that the manuscript was almost certainly folded and carried in a pocket, consistent with its use for instruction.

Although the Sfera does not further our knowledge of western exploration and expansion, it serves a vital role in demonstrating what Europeans at the dawn of the age of exploration and before the invention of print knew and what they wanted to know about the world around them. It shows us that members of the merchant class wanted to know the secrets behind the movement of the heavens and the scientific explanations of solar and lunar eclipses. They wanted to know the layout of the Holy Land, including both Christian and Islamic sites, and the subsequent history of the region. Finally, the fragmented maps that dominate the margins in the last quarter of the work demonstrate the practical working knowledge that a merchant needed to conduct his business, such as where various ports were located and how far away from each other they were. Educational texts are often not the most advanced scholarship, but they are vital for communicating the information most needed by the majority of the population. As such, Dati’s Sfera provides an insight into European consciousness and its view of the world.