Stars in History of Science

Very exciting news for the field of history of science came out about a month ago: the first known star catalogue ever written was finally discovered in an old parchment originally kept at St. Catherine’s Monastery, in Sinai, Egypt. The parchment consists of 146 leaves of Syrian texts containing –behind them– a palimpsest, which is an older work that has been scraped out.

Scholars and scientists are now able to access palimpsests such as these using multispectral imagery. What they found in the case of this parchment was a set of coordinates for the position of stars belonging to the Corona Borealis constellation. As stars are seen to be shifting slowly to the west in a movement known as precession, the values are different from the modern ones and –more surprisingly still– they even differ from those given by Ptolemy in the oldest catalogue extant. So, the question that remained was: whose measurements were they? And when were they taken? By accounting for the movement of precession, it was possible for scholars to determine that the coordinates were taken around the second century B.C. and would most likely belong to the ancient astronomer Hipparchus, whose catalogue is known only because it was mentioned by later authors.

Stars are a fascinating topic for us members of the RUTTER project, for they played a crucial role in navigation. Latitude measurements at night were based on the determination of the position of the Poles through visible stars –Poles which were still relatively distant from Polaris and even more so from the Southern Cross, in the northern and southern hemispheres respectively. Longitude values, although not so frequent, could also be taken through the stars. The lunar distance method, for instance, could be used by measuring the angular distance between the moon and a particular fixed star in two different places. Sailors in the Indian Ocean had also developed a stellar compass rose in which the rising and setting position of 16 stars would mark the cardinal points and, thus, serve as indicators of direction.

It was with great excitement that we read about such an amazing historical finding as a part of Hipparchus star catalog, and we wonder at the potential impact that this discovery will have. [Inês Bénard]

Narrating Magellan Today: An Exhibition About the Circumnavigation in a Small Italian Town

Is it possible today to narrate Magellan’s experience around the world outside Iberia with an exhibition? Even more so, in a rural small Italian town, possibly the most different place from the world of ocean navigation that gave birth to the Portuguese explorer? This was the challenge I faced when I decided to organize the exhibition Il Giro del Mondo in 500 Anni, on display from September 17th, 2022 to January 31st, 2023 in the town of Guastalla, a small renaissance town in the rural heart of northern Italy. The exhibition is designed to take visitors step by step along Magellan’s journey, to visit the places of the circumnavigation and the wonders encountered by its protagonists, from the giants of Patagonia to the penguins of the eponymous Strait.

The planispheres exhibited in the rooms of the local Gonzaga’s Ducal Palace are meant to show how in the age discoveries and encounters different ways of representing the world could exist simultaneously. For a long time, geographers and cartographers debated the possibility of Asia and America being united. Magellan himself, in order to reach the Mar del Sur, i.e. the Pacific Ocean, had to find the passage that still bears his name. Finally, we wanted to show to visitors the connection between this global journey and the local context: Guastalla. On display in the exhibition are a series of objects: paintings, religious vestments, and textbooks, in which the vast world peeps into the erudite culture and daily reality of the small town. Geography books for use in local schools testify to the knowledge about the world and its nature that entered people’s collective awareness. Depictions of animals and plants on textiles and pictorial canvases tell us of a cultural globalization which was different from how we know it today, but no less pervasive. Even Bernardino Baldi’s poetical treaty La Nautica, displayed in the exhibition, tells of distant ways of transmitting scientific knowledge derived from early modern oceanic sailings.

Among the exhibition’s purposes was the desire to showcase the documentary and bibliographic heritage of the local Maldotti Library, from which all the iconographic and book material on display comes. This institution represents a still too little-explored treasure of historical sources of local, but also regional, and even national importance. The mounting of an exhibition on a global theme, a bold choice for a vibrant but small reality such as Guastalla, testifies to the great research potential guarded by local cultural and archival institutions, of which the Maldotti Library has been the centerpiece for more than two hundred years.

Last but not least, it is important to mention the educational value of the exhibition, designed to be visited by schoolchildren of various grades as an interactive and audiovisual moment of learning. In fact, the exhibit features a three-dimensional model of the ship Victoria, the only one to return to Spain in 1522, as well as various wooden reproductions of navigational instruments used by 16th-century navigators, made to be used by visitors. It was also possible to borrow a mobile planetarium from the University of Parma, housed in the rooms of the Ducal Palace, to show visitors the celestial vault of the southern hemisphere as seen by Magellan and his sailors after crossing the equatorial line.

I hope I have achieved the goal of narrating Magellan in one context not directly affected by the tradition of ocean voyages. Have I succeeded? I leave that answer to the exhibition visitors. [David Salomoni]

From the “leap day before the calends of March” to the 29th of February – Part III

Taking up from where we left in our latest episode, and to draw some conclusions, we can see how the need for tables with astronomical references, such as those for the Sun’s Declination, led to a new representation of the month of February: in the three common years with 28 days, in the “leap” years with 29 days— actually switching the added or “leap” day to the end of the month, from being a duplication of February 24th, to the new and shiny 29th of February. But the result is the same: the month of February had 29 days every 4 years.

And even after the Gregorian Calendar Reform in 1582, we still have leap years and their model still has an intercalary day. Formerly, the leap day was introduced after February 23rd, now the leap day is added at the end of the same month of February. Formerly, February 24th was repeated and called the “leap day before the calends of March” (bis sextus ante calendas, remember?), but now the numbering of the days of February goes from 1 to 29 without interruption. It is as if there was no longer an intercalary “leap” day, but simply a month of 29 days, in which the 29th is an additional or “extra” leap day. The result is the same, as shown by the fact that intercalations at the end of the year were already used in the traditional Roman calendar and in Julius Caesar’s reform.

Perhaps this comes most naturally to us because we no longer organize the dates or the calendar in the manner of the Romans of the Republic or the Empire. But the basis of this solution, having years with days added every fourth, remains Julius Caesar’s because we prefer, like him, an annual solar calendar which follows the seasons, having equinoxes and solstices on (roughly) constant dates.

Here, in the Sun’s Declination Tables used by early modern mariners, we witness the transition from the medieval model of the month of February in the Julian calendar, still with Roman dates, to a month of February with the Indo-Arabic numerals we still use today.

Quadrennial table February page, from the Évora Nautical Guide, ca.1516.

This transition reflected, in some way, the transition from the use of Roman numerals to Arabic numerals, and the transition from handwritten to printed documents. The Évora Nautical Guide (shortly to be made available through our RUTTER Digital Library), may be among the first Portuguese calendars printed with the longer month of February including a 29th day—without a patron saint! [José Madruga]

The Ambassador and the Captain: a Classical Story of Espionage?

Drawing on previous blog posts (Surprises Awaiting the Visitors to Simancas Archive and A 16th-century Run for Gold and for… an Accurate Nautical Rutter?), we could not fail to report more novelties on Manuel Mesquita Perestrelo. It is another instance of how the Secretaria de Estado Portugal (in Simancas Archive) holds really a surprise at every corner.

In December 1569, King Philip II appointed a new ambassador to Portugal: D. Juan de Borja (1533-1606). The ambassador came from a prestigious noble house (he was the son of the famous Francisco de Borja, the duke of Gandia who renounced his title and later was appointed as the Jesuit general in Rome) and became known as the espía-embajador (the spy-ambassador). Shortly after arriving in Lisbon in 1570, Borja wrote a small warning to the Spanish court. He claimed that Manuel Mesquita Perestrelo had been convinced by a Portuguese pilot to return to Portugal, as he was given a formal pardon letter by the Portuguese King. According to the best rumours in Lisbon, Borja asserted that Perestrelo was to be named captain of the Portuguese Moluccas.

D. Juan de Borja (1533-1606)

Indeed, Perestrelo had fled to Spain during the 1560s. This was owed to his previous imprisonment in Lisbon. Perestrelo had been accused of siphoning money off for personal profit and mainly for not opposing John Hawkins’s fleet in 1562 at Mina, where he had succeeded as captain due to the previous captain’s decease. As Perestrelo considered this to be an injustice against him, he fled to Spain. However, some years later, the Portuguese ambassador in Spain seems to have mediated his return. But why would Borja, in 1570, be so worried about such an apparently insignificant story?

Manuel Mesquita Perestrelo's manuscript

The answer resides in a second letter by Borja to King Philip II. In this letter, Borja had discovered that Perestrelo had orders to attack the Spanish in the Philippines and had confirmed with several informants that he was, in his own words, a “great mariner and cosmographer” (let us not forget Perestrelo’s 1575’s famous nautical rutter on the East African coast). For this reason, Borja regretted deeply that he could not prevent Perestrelo’s departure. The letter seems to imply that Borja tried to disrupt Perestrelo’s expedition (which departed in 1570). Still, it remains unknown whether Borja approached Perestrelo to convince him to return to Spain. What remains certain is that this sort of episode remained very common all along the 16th century, when the acquisition of nautical knowledge could justify espionage. Borja knew well that in order to sustain a successful maritime empire, espionage under the utmost secrecy was a necessity. So too did King Philip II when he ordered Borja, in his December 1569 instruction, to use mucho segredo (much secrecy) in his important acquisitions in Portugal. Indeed, Borja’s story with Perestrelo is merely one of the espionage episodes of Borja’s embassy in Portugal. [Nuno Vila-Santa]

History of Science and Meeting the Sustainable Development Goals (II)

The 17 Sustainable Development Goals (SDGs) are the heart of the 2030 Agenda for Sustainable Development adopted by all the member states of the United Nations. They represent a call for action by all countries —developed and developing— to, among other aims, improve health and education, reduce inequality, and spur economic growth. The RUTTER project aligns with key aspects of the Declaration, goals and targets of the 2030 Agenda, which promotes a world of cultural diversity, and its appreciation, “to foster intercultural understanding, tolerance, mutual respect and an ethic of global citizenship” (par.36).

Creating an open platform giving access to collections which preserve interconnected histories, of value to many cultures, RUTTER contributes “to accelerate human progress, to bridge the digital divide and to develop knowledge societies” (par.15).

Our digital library will be a gender-inclusive endeavour, thus furthering Goal 5, target 5.b, to “Enhance the use of enabling technology, in particular information and communications technology, to promote the empowerment of women.”

From a fundamental point of view, given the nature of the collections we cover, and how we will be promoting the study of different languages with scholarly equality, we will align with par. 36 of the Declaration, “to foster intercultural understanding, tolerance, mutual respect and an ethic of global citizenship and shared responsibility.”

The map above, from the project “CenterNet-An international network of digital humanities centers”, highlights the existence of teams and projects involving digital humanities all over the world. DH work tends by nature to form international networks, breaking geographic and cultural barriers, driven by the desire to learn and to share knowledge. Because our editions will be online, free to access, and with a multilingual interface, we will in fact bring languages and discourses from developing countries as equal interlocutors into the world-wide forum that the internet has become. — We’ll give details about our methods in the next post in this series. [S. Munzi and J. Acevedo]

From the “leap day before the calends of March” to the 29th of February – Part II

Pilots and navigators of the 15th and 16th centuries needed the Sun’s Declination Tables to determine their daily position on ocean voyages, using the reading of the sun’s altitude values they got from the astrolabe or quadrant.

As the Julian calendar had a cycle of 4 years, three common and one leap year, the most rigorous Tables had to be quadrennial. The calculations were made by astronomers from astronomical tables such as the Tables of the place of the sun from Abraham Zacuto’s Almanach perpetuum (Leiria, 1496). Astronomers calculated and sailors learned to read and use; sometimes they copied them for their notes or seaman’s books, other times they used printed editions that began to appear in Portuguese, as in the Évora Nautical Guide (Guia Náutico de Évora) (Lisbon, ca. 1516).

The four-year Tables presented the 1461 days of the four years of the Julian cycle. There, the month of February of the “leap year” actually has 29 days, but without the dating format and Roman numerals by Calends, Nones and Ides, only with the series of days of the month written in Arabic numerals. In most handwritten documents — Livros de marinharia, Atlas and Códice Bastião Lopes - we find the quadrennial Tables of the Sun’s declination. Let's look at the “Treaty of the Sphere” section in Évora Nautical Guide, printed in Portuguese:

“Treaty of the Sphere” in Évora Nautical Guide (Lisbon, ca. 1516), BPE, Res 0404, fol. Biv, detail.

This Guide includes the values of the “Place of the Sun” and “Solar Declination”. On the 23rd of February of the leap year (1st column, 3rd row), it indicates the place of the leap year (lugar do bis.) and the vigil of Saint Matias, but the last day of the month is the 29th (1st column, 9th row), without a Sunday letter , only with the values of the place of the sun and the declination of the sun (9th row, columns 4th to 7th). In traditional Julian calendars, the leap day took the place of 24th of February, Saint Matias’ day moved to the 25th of February, and the month retained its count of 29 days.

Here, the day itself 29th of February is writen, but without a Sunday letter (or, if we want we could repeat the Sunday letter from the previous day, ‘c’). Only the values in degrees and minutes of the ‘Place of the Sun’ and the ‘Declination of the Sun’ are displayed. The “leap place” of the traditional Julian calendar, which repeated the 24th of February, no longer makes sense because the “added day” is now the 29th of February, as we use it today in the most diverse calendars, printed in diaries or electronically. [José Madruga]

History of Science and Meeting the Sustainable Development Goals (I)

What’s the link between the Rutter project and sustainability? You will find out in this series of three posts.

At our project we draw directly from early modern scientific manuscripts, bringing them to light from half-forgotten shelves, showing their relevance, and making them available worldwide as much as possible.

Touching the sources themselves is key for an honest and fresh look into the past, for a real understanding, instead of a projection of our views, and this work can be exciting and fascinating, but it is hard work indeed, and it imposes limitations as far as open science and accessibility are concerned. Some typical scenarios are:

• Only one or just a few copies exist of a specific manuscript work, physically located in one/few libraries;
• The texts are hard to read unless the reader has a certain degree of expertise in paleography;
• The texts are written in the languages of the 15th-17th centuries;
• Some texts are considerably long, making it difficult to quickly retrieve information on specific topics.

Porllogo (instead of modern “Prólogo”) of the Esmeraldo de Situ Orbis, from the oldest manuscript (ca. 1750) kept at the Public Library of Évora (BPE COD. CXV/1-3).

Applying Digital Humanities techniques to Iberian and Arabic maritime works opens new ways to approach these early scientific and technical texts and to bypass most of their limitations at once. The transcription of texts into digital formats (XML), following international standards (TEI), with the modernization of the language, makes them actually available from everywhere and to anyone, regardless of sex, nationality, age or race. More about this in the coming weeks, stay tuned! [S. Munzi and J. Acevedo]