Welcome to my web site.
I am a historian of science working at the Centro Interuniversitário de História das Ciências e da Tecnologia, at the University of Lisbon (CIUHCT-UL), and I teach at the Master Program in the History and Philosophy of Science. I am presently Chair of the Department for the History and Philosophy of Science.

Here you'll find information on my research, my papers, books and other topics. I have a number of ongoing projects with students and collaborators and will post some information here.

Research that's keeping me busy:

The edition of Pedro Nunes's Works (Obras de Pedro Nunes), by the Lisbon Academy of Sciences and the Calouste Gulbenkian Foundation is still my most absorbing project. The first six volumes are published: that is, ALL printed works by Pedro Nunes are now available in a modern, annotated edition. They can be bought at the Bookshop of the Calouste Gulbenkian Foundation. The volume on Nunes' manuscripts (vol. VII) is nearly completed; it should be ready in a couple of months. I am already working hard on vol. VIII (biographical materials and documents). See here for updated information.

In the past years I got more and more interested in problems in the history of cartography. I have been doing this work with Joaquim Gaspar. A few years ago we investigated the origins of the Mercator Projection -- and got some remarkable results; more recently we looked into the first charts with visual depictions of magnetic information, namely isogonic lines. Here are some of our papers: Joaquim Alves Gaspar and Henrique Leitão, "Squaring the Circle: How Mercator constructed his Projection in 1569", Imago Mundi, 66 (2014) 1-24; Henrique Leitão and Joaquim Alves Gaspar, "Globes, rhumb tables and the pre-history of the Mercator projection", Imago Mundi, 66 (2014) 180-195; Joaquim Alves Gaspar and Henrique Leitão, "How Mercator Did it in 1569: From Tables of Rhumbs to a Cartographic Projection", Newsletter of the European Mathematical Society, nº99 (March 2016) 44-49; Joaquim Alves Gaspar and Henrique Leitão,«What is a nautical chart, really? Uncovering the geometry of early modern nautical charts», Journal of Cultural Heritage, 29 (2018) 130-136Joaquim Alves Gaspar and Henrique Leitão, «Luis Teixeira, c.1585: The earliest known chart with Isogonic Lines», Imago Mundi, 70 (2018) 221-228; Joaquim Alves Gaspar and Henrique Leitão, «Early Modern Nautical Charts and Maps: Working through different cartographic paradigms», Journal of Early Modern History, 23 (2019) 1-28. More papers are submitted and will appear later this year. 

I am working with José Madruga Carvalho on the history of the Gregorian Reform of the Calendar in Portugal. The 1582 reform promoted by Pope Gregory XIII is a fascinating but sometimes very technical topic. There is an interesting body of documents on the correspondence between Portuguese astronomers and Roman authorities in the 16th century, but this was never studied in detail. A couple of years ago I traced unknown documents and we are now putting everything together and writing a book that we wish will become a reference work for the Portuguese reader.

I am working with Bernardo Mota on the edition of Francisco de Melo's mathematical works: Francisco de Melo: Obras Matemáticas. Melo (ca. 1490-1536) was a fine mathematician, perhaps the best Portuguese mathematician in the generation before Pedro Nunes. Volume I [Latin text and translation] is already published and got the prestigious prize for academic translation. Samuel Gessner published an extended Review of our book in Historia Mathematica, 45 (2018) 182-185. We are now working on volume II [Commentary and studies], which we plan to publish in 2019. See here for more information.

Luana Giurgevich and I have been engaged for some years on a wide research of old libraries in Portugal. Our initial objective was to study the circulation of scientific books in Portugal but we soon realized that a broader approach was needed. We ended up examining in detail the contents of hundreds of old libraries; the result was our 900-page book: Clavis Bibliothecarum: Catálogos e Inventários de Livrarias de Instituições Religiosas em Portugal até 1834 - an exhaustive list of nearly 1.000 catalogues of ca. 400 ancient libraries plus hundreds of related documents. (This book was awarded a "Menção Honrosa" of the Prize "Lusitania - História", Academia Portuguesa da História, 2016). Here's a review to the book, by Mário Santiago de Carvalho, in Revista Filosófica de Coimbra, 25 (2016) 462-464. The National Library [Biblioteca Nacional de Portugal] set up a Companion Site to the Book, with hundreds of digitised library catalogues. We are now researching the educational activities around these libraries and these ecclesiastical institutions.


September, 2019

I am now starting RUTTER: Making the Earth Global (ERC AdG 833438). It is a new, ambitious, five-year Project to study early modern sailing directions (rutters) and ship's logbooks. I plan to make public some results along the way.

July, 2019

This is the site of the new Gynecia Project [PI: Cristina Santos Pinheiro; co-PI: Bernardo Machado Mota]. I am Scientific Advisor.

May, 2019. New book

Bernardo Jerosch Herold, Thomas Horst, Henrique Leitão (eds.),
A História Natural de Portugal de Leonard Thurneysser zum Thurn, ca. 1555-1556
(Lisboa: Academia das Ciências de Lisboa, 2019)
ISBN: 978-972-623-368-8, 129 pp. [free download here]

March, 2019

My latest paper is now online: Joaquim Alves Gaspar and Henrique Leitão, «Early Modern Nautical Charts and Maps: Working through different cartographic paradigms», Journal of Early Modern History, 23 (2019) 1-28. 

November, 2018

This is the site of the new Astra-Project [PI: Helena Avelar]. I am Scientific Advisor.

October 29, 2018

A brief article I wrote for newspaper Publico: Pedro Nunes e as voltas da linha de rumo. This was the last article in the series on History of Science by the Medea-Chart team.

September 5, 2018. A sample of my papers in 2018-2017:

Luís Campos Ribeiro and Henrique Leitão, «Astrology with new eyes: The telescope in astrological prognostication», Journal for the History of Astronomy, 49 (2018) 345-362; Joaquim Alves Gaspar and Henrique Leitão, «Luis Teixeira, c.1585: The earliest known chart with Isogonic Lines», Imago Mundi, 70 (2018) 221-228; Joaquim Alves Gaspar and Henrique Leitão,«What is a nautical chart, really? Uncovering the geometry of early modern nautical charts», Journal of Cultural Heritage, 29 (2018) 130-136Henrique Leitão and Antonio Sánchez Martínez, «Zilsel’s thesis, maritime culture, and iberian science in early modern Europe», Journal for the History of Ideas, 78 (2017) 191-210; Thomas Horst, Bernardo Herold e Henrique Leitão, «A “História Natural de Portugal” de Leonhard Thurneysser zum Thurn, ca. 1555-1556», Ágora. Estudos Clássicos em Debate, 19 (2017) 305-334;  Henrique Leitão and Antonio Sánchez, «Too much to tell: narrative styles of the first descriptions of the natural world of the Indies», History of Science, 55 (2017) 167-186.

September, 2018. Frontiers in the History of Science.

 New series: Frontiers in the History of Science, Birkhäuser, Basel. Editor: Vincenzo de Risi. I am one of the Associate editors.
Frontiers in the History of Science is designed for publications of up-to-date research results encompassing all areas of history of science, primarily with a focus on the history of mathematics, physics, and their applications. Graduates and post-graduates as well as scientists will benefit from the selected and thoroughly peer-reviewed publications at the research frontiers of history of sciences and at interdisciplinary “frontiers”: history of science crossing into neighboring fields such as history of epistemology, history of art, or history of culture. 

July 2018 - Melo's Obras Matemáticas is online (and free)!

It recently came to my attention that my book with Bernardo Mota: Francisco de Melo: Obras Matemáticas[vol. I: Texto Latino e Tradução] (Lisboa: Centro de Estudos Clássicos e Biblioteca Nacional de Portugal, 2014) is now fully downloadable (!) at the Repositório da Universidade de Lisboa.

See also the recent detailed Review of the book by Samuel Gessner here: Historia Mathematica, 45 (2018) 182-185

June, 18, 2018

A small piece I wrote for newspaper Público on the arrival of news about Galileo to China: "Galileu chegou à China no texto de um português". This is part of a series on History of Science by the Medea-Chart team.

June 2018 - Conimbricenses.org

The excellent site Conimbricenses.org is now online (beta version). (Director: Mário Santiago de Carvalho; editor: Simone Guidi ).
I am at the Advisory Board.

Recent and next speaking engagements:

November 8. Universidade: mas que sítio é este?, Masterclass Ludus.

Subpages (1): Old Stuff