The metre is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second, where the second is defined by a hyperfine transition frequency of caesium.
Antonio de Ulloa was a Spanish Navy officer, scientist and colonial administrator. At the age of nineteen, he joined the French Geodesic Mission to South America. The mission took more than eight years to complete its work, during which time Ulloa made many astronomical, natural, and social observations in South America. The reports of Ulloa's findings earned him an international reputation as a leading savant. Those reports include the first published observations of the metal platinum, later identified as a new chemical element. Ulloa was elected as a fellow of the Royal Society in 1746, and as a foreign member of the Royal Swedish Academy of Sciences in 1751.
The history of geodesy (/dʒiːˈɒdɪsi/) began during antiquity and ultimately blossomed during the Age of Enlightenment.
The year 1749 in science and technology involved some significant events.
Pierre Bouguer was a French mathematician, geophysicist, geodesist, and astronomer. He is also known as "the father of naval architecture".
Charles Marie de La Condamine was a French explorer, geographer, and mathematician. He spent ten years in territory which is now Ecuador, measuring the length of a degree of latitude at the equator and preparing the first map of the Amazon region based on astro-geodetic observations. Furthermore he was a contributor to the Encyclopédie.
The year 1735 in science and technology involved some significant events.
Pichincha is a stratovolcano in Ecuador. The capital Quito wraps around its eastern slopes.
Louis Godin was a French astronomer and member of the French Academy of Sciences. He worked in Peru, Spain, Portugal and France.
The Ciudad Mitad del Mundo is a tract of land owned by the prefecture of the province of Pichincha, Ecuador. It is located at San Antonio parish of the canton of Quito, 26 km (16 mi) north of the center of Quito. The grounds contain the Monument to the Equator, which highlights the exact location of the Equator and commemorates the eighteenth-century Franco-Spanish Geodesic Mission which fixed its approximate location; they also contain the Museo Etnográfico Mitad del Mundo, Ethnographic Museum Middle of the Earth, a museum about the indigenous people ethnography of Ecuador.
Gabriel Mouton was a French abbot and scientist. He was a doctor of theology from Lyon, but was also interested in mathematics and astronomy. His 1670 book, the Observationes diametrorum solis et lunae apparentium, proposed a natural standard of length based on the circumference of the Earth, divided decimally. It was influential in the adoption of the metric system in 1799.
The Paris meridian is a meridian line running through the Paris Observatory in Paris, France – now longitude 2°20′14.02500″ East. It was a long-standing rival to the Greenwich meridian as the prime meridian of the world. The "Paris meridian arc" or "French meridian arc" is the name of the meridian arc measured along the Paris meridian.
A toise is a unit of measure for length, area and volume originating in pre-revolutionary France. In North America, it was used in colonial French establishments in early New France, French Louisiana (Louisiane), Acadia (Acadie) and Quebec. The related toesa was used in Portugal, Brazil, and other parts of the Portuguese Empire until the adoption of the metric system.
José Antonio de Mendoza Caamaño y Sotomayor, 3rd Marquis of Villagarcía de Arousa was a Spanish colonial administrator in the Americas. From 4 February 1736 to 15 December 1745 he was Viceroy of Peru.
Pedro Vicente Maldonado y Flores was an Ecuadorian scientist who collaborated with the members of the French Geodesic Mission. As well as a physicist and a mathematician, Maldonado was an astronomer, topographer, and geographer.
Jorge Juan y Santacilia was a Spanish mariner, mathematician, natural scientist, astronomer, engineer, and educator. He is generally regarded as one of the most important scientific figures of the Enlightenment in Spain. As a military officer, he undertook sensitive diplomatic missions for the Spanish crown and contributed to the modernization and professionalization of the Spanish Navy. In his lifetime, he came to be known as el sabio español. His career as a public servant constitutes an important chapter in the Bourbon Reforms of the 18th century.
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 0.5 Hz.
In geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length.
The history of the metre starts with the Scientific Revolution that is considered to have begun with Nicolaus Copernicus's publication of De revolutionibus orbium coelestium in 1543. Increasingly accurate measurements were required, and scientists looked for measures that were universal and could be based on natural phenomena rather than royal decree or physical prototypes. Rather than the various complex systems of subdivision then in use, they also preferred a decimal system to ease their calculations.
The French Geodesic Mission to Lapland was one of the two geodesic missions carried out in 1736–1737 by the French Academy of Sciences for measuring the shape of the Earth. One expedition was sent to Ecuador to perform measurements near the Equator; the other was sent to Meänmaa to perform measurements near the Arctic Circle.
