The Descripción de las provincias del virreinato del Perú, printed a few provinces a year in an almanac
A survey of ninety-six provinces of a South American viceroyalty, issued serially in the annual almanac of the chief cosmographer of Peru and arranged by bishopric. Each entry gives bounds in leagues, climate, crops and yields, mines, rivers and parishes, and sometimes a population figure. Its closing paragraph says how it was made and why it took so long: the corregidores were slow, and many returns came back too thin to use.
Why this wins its question: The descriptions are cited constantly by Andean historians and almost never described, so a reader who asks what they are gets a title and a date. What wins the question is the pairing of a sample entry with the compiler's own account of how the entries were got: Huancavelica in one page - latitude to the second, mine discovered 1563 and registered on 1 January 1564, villa founded 5 August 1572, a guild of 40 miners paid a fixed price per quintal, 124 furnaces, a mine in decline after 200 years - and then, at the end of the survey, the sentence that says the corregidores were slow, that many returns arrived too thin and had to be sent back, and that successors had to be re-questioned. That admission is what lets a modern reader use the numbers correctly, and it is exactly what a summary of the work leaves out.
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 survey opens by measuring the kingdom rather than praising it. Peru, it says, was discovered in 1526 and its conquest begun in 1531; north to south it runs from 3 degrees 25 minutes south, where it borders the kingdom of Quito on the coast of Tumbes, to 25 degrees 10 minutes at the middle of the despoblado of Atacama where it borders Chile, 432 leagues; and taking in the whole extent of its viceroyalty, as far as the last southern lands discovered at 56 degrees 50 minutes, 1068 maritime leagues. Its width, as far as the line of demarcation between Spanish and Portuguese America, is at most 680 leagues.
The administrative frame is stated in the same paragraph: the whole viceroyalty is divided into 96 provinces distributed in three jurisdictions belonging to three royal audiencias, of which the first, the audiencia de los Reyes or Lima founded in 1535, is listed province by province. The descriptions themselves are then grouped by ecclesiastical district - the archbishopric of Lima first, then the bishoprics of Arequipa, Trujillo, Huamanga, Cuzco and the archbishopric of La Plata or Chuquisaca - so a civil survey is filed under a church map.
What a province entry actually contains can be read off one of them. For Angaraes: its boundaries with six neighbouring provinces, its dimensions - 24 leagues east to west by 12 wide, with much irregularity of figure - a cold temperature except in one or two ravines, and the note that in the jurisdiction of the curato of Acobamba alone some 25,000 fanegas of wheat are taken in a year, with which the villa is supplied. Then the ichu grass cut as fuel for the quicksilver furnaces, which leaves no small profit because the miners pay well for it; the llamas that carry ore from the hill to the furnaces; a coal seam at Pallalla left forgotten "por no usarse en este reyno"; silver mines worked with little profit; earths used as pigments; the rivers; and, at Acobamba, stones like pyramids with seats cut in them which have been there since before the conquest.
The entry for the villa of Huancavelica is where the survey is most quantitative, and the numbers are of an industry in decline. Its latitude is given as 12 degrees 48 minutes 24 seconds south and its distance from the sea as at least 40 leagues. The quicksilver mine, "el alma de todos los minerales del reyno", was discovered in 1563 and registered on 1 January 1564, and the villa was founded on 5 August 1572 by the viceroy Francisco de Toledo. The mine is not worked on the king's account but by a guild of miners who deliver all the quicksilver they take out into the royal treasury, the king allowing them a fixed price per quintal; the number of miners is 40 and is not always complete, because after the much metal taken out in these 200 years and the depth of the workings the mine, and with it its profits, has gone into decline. There are 124 furnaces for refining quicksilver in the neighbourhood of the villa, and the mouth of the mine is about a league from it.
Population appears as a round figure attached to a jurisdiction, not as a census: the inhabitants of the villa are put at 8,000, those of the rest of the province a little fewer, and the neighbouring province of Castrovireyna - rugged and sterile, and for that reason thinly peopled - at scarcely 6,900 for 22 leagues by 35 or 40. The survey gives no indication of how either number was arrived at.
The survey corrects maps where it can, and names what it is correcting. Describing the Patagonian coast in latitudes - Cabo Blanco at 47 degrees 10 minutes, the bay of San Julian at 49 degrees 12 minutes, the Cabo de las Virgenes at 52 degrees 30 minutes, so named because Magellan reached it on St Ursula's day in 1520 - it reports that no permanent rivers of any consideration exist on that whole coast, however some maps paint them; that the account of Anson's voyage, on false relations, gives San Julian a great river issuing from a large lake, a fiction found in some maps; and that in 1746 and 1747 the coast was minutely visited by a frigate named the San Antonio sent by the king for that purpose, which from the river of los Sauces found no permanent river at all, nor fresh water at San Julian. The same pages place the islands called Falkland, from a Scotsman of a town of that name, and Malvinas from the ships, under the government of Buenos Aires.
The closing paragraph of the whole survey is a statement of method and of its failures, in the author's own voice, and it is the most valuable passage in the work. The descriptions, it says, have been printed annually as the notices were acquired; all that time was necessary because of the slowness of the corregidores, some excusing themselves with the occupations of their offices, others by the want of capable persons in the provinces to whom the relations could be entrusted; many sent them "diminutas, y nada ajustadas á la instruccion que se les remitió", so that it was necessary to send them back; and because it is not easy to learn the qualities of a province where there is nobody with the instruction to understand what is being asked, it was necessary to re-question their successors and to investigate with one and another by every means until the point was cleared up.
That paragraph also fixes what the survey is worth as evidence, and this object states the consequence rather than leaving it to the reader. Since each province was described from a return supplied by its corregidor, and the compiler says himself that the returns varied from adequate to too thin to use, the accuracy of the work varies province by province with the official who answered; figures such as the 8,000 inhabitants of Huancavelica are administrative reports passed through one editor, not counts, and nothing in the printed text distinguishes the provinces whose returns satisfied him from those he had to send back.
The serial form is confirmed from outside the work. The eulogy printed after the author's death describes his annual almanacs as being in two parts, one adorned with physico-medical dissertations and the other containing the descriptions of the provinces of Peru, Chile and Buenos Aires, and regrets that a second edition of that geography was never made - so what survives is a work published a few provinces at a time over years, never revised as a whole by its author.
The text read here is not the almanac sheets. It is the collected printing made by Manuel de Odriozola at the Imprenta del Estado in Lima in 1872, as the third tome of his Coleccion de documentos literarios del Peru, whose index runs the descriptions from page 11 to page 260 and lists them province by province under each bishopric. Nothing in the volume states which almanac year each province came from.