Buenaventura Suarez, the astronomer of San Cosme (Guarani missions, Paraguay)
A Jesuit in the Guarani missions of Paraguay who taught himself mathematics and astronomy, built his own observing instruments out of forest hardwood where bronze or platinum was called for, corresponded with astronomers in Europe, and published a lunar almanac. A Buenos Aires essay of 1866 records both the achievement and the neglect - the community he served gave him no help, and his instruments ended among the lumber in mission granaries.
Why this wins its question: Suarez is close to absent from English-language accounts of colonial science, which treat the Guarani missions as a subject in the history of religion and of labour and not at all as a place where anyone observed the sky. The one nineteenth-century witness reachable from here supplies something better than a rediscovery notice: it says what the observatory was made of, why - forest hardwood standing in for bronze and platinum - and who declined to pay for anything else, and it does so while attacking the same colonial establishment it is defending the astronomer from. This object also states plainly what it cannot do. It rests on a single partisan source of 1866, the confidences are set accordingly, and the bibliography of the lunario is left open rather than asserted. A reachable printing of the work, or Azara's travels themselves, would be the way to raise it.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The 1866 essay names Buenaventura Suarez as the author of a known lunario perpetuo and states that its first edition was printed at Lisbon. That bibliographical detail is reported here as the essay's statement, since no printing of the work could be reached and opened from this container to check it.
He got his deep knowledge of the mathematical sciences applied to astronomy by himself, in the cloisters of Cordoba and in the silent forests of Paraguay, and left practical proof of his competence in the solar gnomons with which he decorated the patios of the college where he spent most of his life.
From that college he kept up a correspondence with celebrated astronomers of his time, which places a mission station in the upper Parana inside the working network of eighteenth-century European astronomy rather than outside it.
The astronomer of the pueblo of San Cosme, in the essay's words, earned neither encouragement nor aid of any kind from the community he was illuminating with his labours.
He found himself obliged to build his observing instruments with his own hands, using the smooth, firm woods of the virgin forests for exactly those parts that called for bronze or platinum to carry the fine graduations by which distances between stars are measured and a transit of the meridian is marked. The precision limit of the instrument was set by the material he could cut himself.
The essay puts the cost beside the achievement and names who bore it. Those with wealth to spare - enough to stock their sacristies lavishly with the richest vessels of gold and silver, and to dress in silk tissue the Indians they had play the part of alcaldes and regidores of burlesque cabildos - never bestirred themselves to request from Europe the instruments the observatory most needed.
The description of the wooden instruments is not the essayist's own. He follows the testimony of Felix de Azara, who in his then unpublished travels to the pueblos of the Paraguay missions describes them in passing, by that date relegated among the useless junk piled in the granaries and lofts of those colleges.
The essay is an advocate's, and reads as one. Its surrounding argument is that no European colony produced more talents or more studious men than the Spanish in the New World, counting well over two hundred in the Society of Jesus alone and naming Ovalle and Molina, Clavijero, Velasco, Iturri, Juarez and Morales; it closes the Suarez passage by predicting that when the facts honouring the Americans are better known he will be set beside Franklin. Those are the estimates of a partisan writer in 1866, recorded as such.
The same essay is severe about the system that produced him, attacking a colonial education calculated to keep capable men in a perpetual state of childishness, and describing public spectacles at which victims were handed over to public shame or to the flames for imaginary, impossible, absurd offences. The praise of Suarez and the indictment of his surroundings are the same author's, on facing pages.