Observatorio Astronómico de Santa Fe de Bogotá (begun 1802, finished 1803), described by Francisco José de Caldas
An octagonal tower raised in the garden of the Real Expedición Botánica at Mutis's expense, begun 24 May 1802 and finished 20 August 1803, with a meridian line on the floor of its main room and a gnomon of 37 feet 7 inches. Caldas, who took charge in December 1805, printed its position in his own weekly along with the reasons it was not yet certain: cloud at three December solstices, and no European observatory had sent back a single corresponding observation of Jupiter's satellites.
Why this wins its question: The Bogotá observatory is usually met in English as a one-line fact - built by Mutis in 1803, often called the first in the New World - with nothing behind it, and the "first" is asserted more often than it is sourced. This object goes to the description Caldas himself printed and takes from it the things a one-line fact cannot carry: the gnomon of 37 feet 7 inches thrown by a hole in the vault onto a meridian line, the crown's instrument list set beside the three cases lost at Cádiz, a Graham pendulum traced from La Condamine's equator mission through a Quito friar and an Audiencia to this tower, and above all the position published with its own defects attached - three clouded December solstices, and not one corresponding observation returned by any European observatory. It also declines to repeat the "first in the Americas" claim, because the page does not make it, and prints the passage in the same volume that blames the province's indigenous dead for their own extermination.
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 dates and the patron are given by Caldas in his own article, headed "Descripcion del Observatorio astronómico de Santa Fé de Bogotá, situado en el jardin de la real Expedicion botánica: por D. Francisco José de Caldas": "El Observatorio astronómico de esta capital, debido á la generosidad y patriotismo del Dr. D. José Celestino Mutis, se comenzó el 24 de mayo de 1802, y se acabó en 20 de agosto de 1803." It stood in the garden of the royal botanical expedition, not on a university or naval site.
The builders are named in a footnote rather than the text: "El arquitecto á quien confió el Sr. Mutis la formacion de los planos y la ejecucion de la obra fué el Hermano Fr. Domingo Petrez, capuchino. Tambien merece una honrosa mencion D. Salvador Rizo, mayordomo de la Expedicion, cuya actividad y celo contribuyó tanto á la pronta conclusion de este bello y sólido edificio."
The building is described as an instrument, not only as architecture. It is "una torre octágona de 13 piés de rey de lado, y 56 de altura", 27 feet across inside the walls, in three bodies. The upper vault is hemispherical and "perforada en el centro": "El agujero de la segunda bóveda da paso á un rayo de luz que va á pintar la imágen del sol sobre el pavimento del salon en que se ha tirado una línea meridiana, y forma un gnomon de 37 pies y 7 pulgadas de elevacion." The highest room, at 60.5 feet and closed by another at 72.5, has "una ranura de Norte á Sur" where the astronomical quadrant for meridian altitudes was placed.
The instrument list separates what the crown gave from what was bought locally. "Los instrumentos donados por S. M. son: un cuarto de circulo de Sisson, dos teodolites de Adams, dos cronómetros de Emery, dos termómetros de Nairne, dos agujas portátiles, y seis docenas de tubos para barómetros." To these the director's own effort added "cuatro acromáticos de Dollond de diferentes longitudes, tres telescopios de reflexion del mismo artista, un grafómetro, octantes, horizonte artificial, muchas agujas, termómetros de Dollond, barómetros, globos, muchos anteojos menores".
The loss is printed next to the gift, in Caldas's own words. A pendulum, a transit instrument, two achromatics with rhomboidal reticle and Herschel's stellar apparatus had been destined for the Expedition by the Marqués de Sonora, "pero por una desgracia funesta á los progresos de la astronomía entre nosotros, se perdieron en Cádiz los tres cajones que los contenian." The equipment of the observatory is therefore reported as what survived a shipping loss, not as what was intended.
One instrument has its provenance traced through four owners, and it ties the observatory to the eighteenth-century geodetic mission to the equator: an astronomical pendulum by Graham, "obra maestra de este artista célebre, que sirvió á los SS. académicos del viaje al ecuador para la determinacion de la figura de la tierra". The footnote adds that La Condamine sold it to Fr. Terol, a Dominican of Quito skilled in clockwork; at his death the Audiencia bought it to set its hours; it passed to D. N. Proaño, a clockmaker; and Caldas took it from him for the observatory.
Caldas states when the work became continuous and who authorised it: "En diciembre de 1805 puso el Sr. Mutis el Observatorio á mi cuidado. En esta época monté los instrumentos y comencé una serie de observaciones astronómicas y meteorológicas que no he interrumpido."
The article publishes the observatory's position together with the reasons it is not yet secure, which is the least triumphal thing in it. On latitude: "las nubes que ocultaron al sol en el solsticio de diciembre de 1805, y en los de 1806, y uno de 1807 no han permitido concluir de un modo invariable é independiente de toda suposicion la latitud de este edificio"; from numerous meridian altitudes of sun and stars taken north, south and at the zenith he gives 4° 36' 6" N, "determinacion que no puede incluir 5" de error". On longitude: many emersions and immersions of Jupiter's first and second satellites were observed through 1806 and 1807, but "no hemos recibido correspondiente ninguna de los Observatorios de la Europa", so only "nuestros primeros ensayos, usando del cálculo" place the meridian 4h 32' 14" west of the Real Observatorio de la Isla de León. Its height above the sea, from a long barometric series, is given as 1352.7 toesas, or 3156.3 varas de Burgos.
The observatory then became the origin of longitudes for surveying the viceroyalty itself, which is what makes it an instrument of government and not only of science. A memoir on the province of Antioquia printed later in the same volume opens its geography with the footnote: "Todas las latitudes de la provincia de Antioquia son boreales, y las longitudes las comienzo á contar del Observatorio astronómico de Santa Fé de Bogotá. Este se halla al occidente del Observatorio real de la isla de Leon 4 horas 32' 10", que en partes del círculo son 68° 2' 30"." The two figures in the one volume disagree by four seconds of time, which is the measure of how provisional the number still was.
Caldas's own comparative claim is modest about equipment and immodest about place: "Si los Observatorios de la Europa hacen ventajas á este naciente por la coleccion de instrumentos, y por lo suntuoso del edificio, el de Santa Fé de Bogotá no cede á ninguno por la situacion importante que ocupa sobre el globo", being in the middle of the torrid zone, seeing the sun at its zenith twice a year, high on the equatorial Andes and so with little to fear from unstable refraction. The advantage he claims is latitude and altitude, and he concedes the instruments.
The counterpoint is in the same volume and should not be left out. The Antioquia memoir whose longitudes are reckoned from this observatory explains the collapse of the province's indigenous population by blaming the dead: of all the Indians of the first times "solo han quedado 4769, tristes reliquias de unos padres crueles y sanguinarios", their extermination coming "sin duda" from human sacrifice, want of agriculture and mutual war. The Creole science housed in this tower shared its era's contempt, and the two things are printed within a hundred and fifty pages of each other.
The limits of what is claimed here follow from the single witness. Everything above is read from one volume - the Paris reprint of 1849, whose editor is an interested party and whose registry entry records that partisanship - and the pages opened contain no observation series, no instrument-by-instrument accuracy audit, no cost, and nothing about what became of the observatory after the Semanario stopped. That it was the first purpose-built astronomical observatory in the Americas is a claim frequently made for it and is not asserted here: the pages read do not say so.