The use of astronomical instruments in Colonial Chile, by Virginia Iommi Echeverría, Instituto de Historia, Pontificia Universidad Católica de Valparaíso (Chile)

The use of astronomical instruments in Chile during the colonial period (1540-1810) remains an obscure subject. Despite a few references in contemporary sources to glasses and armillary spheres, very little is known about the instruments themselves and how they were used. Although the introduction of the printing press in Chile has been dated to near the end of the eighteenth century, the existence of numerous libraries and an active book market by then show the importance of considering bookish astronomy as a fundamental part in this historical task, for not only did books provide theoretical insights into the discipline but also astronomical tables, models and visual instructions for the fabricating instruments. The purpose of this project was to examine these paper instruments as surviving testimonies of astronomical study and practice.

Thanks to an SIS grant, I was able to examine astronomical books printed between the sixteenth and eighteenth centuries preserved at Biblioteca Nacional de Chile in Santiago. One of the founding collections of this library was the books owned by the Jesuits at the moment of their expulsion from the territories of the Spanish crown in 1767, when their possessions were requisitioned and inventoried in detail. The catalogues of belongings found in churches, houses, missions, and colleges show that the members of the order owned several books on astronomy and mathematics. The largest book collection in eighteenth-century Chile was located at the Colegio de San Miguel in Santiago, where more than 6,000 volumes were preserved. By comparing the titles mentioned in the inventories with the present holdings at the Biblioteca Nacional, it was possible to conclude that most of their astronomical books are now lost. One of the few exceptions is the copy of the second volume of Tabulae Primi Mobilis by Andrea Argoli (1570-1657), which is clearly identified as a possession of the Colegio de San Miguel with a handwritten inscription in the frontispiece (see figure 1).

In the inventory, it is described as “Argoli Tabula” (Archivo Nacional de Chile, Fondo Jesuitas, 1767 Vol. 7, fol. 311r). Although not mentioned in the catalogue, a copy of Giovanni Paolo Galluci’s Theatro del mundo y del tiempo contains signs of use that may be helpful for studying astronomical practice in the period (see figure 2). The copy in Biblioteca Nacional belonged to the Jesuit house of San Juan and has numerous handwritten annotations and marks. This research has confirmed that despite the scarcity of sources and objects preserved, a study of astronomical activity in Colonial Chile should give books a central role in the reconstruction of observation, computation and instrument fabrication.