Josef de Mendoza y Ríos facts for kids

Quick facts for kids Josef de Mendoza y Ríos
Portrait of Mendoza y Ríos.
Born	(1761-01-29)29 January 1761 Sevilla, Spain
Died	4 March 1816(1816-03-04) (aged 55) Brighton, England
Nationality	Spanish
Known for	His Tratado de Navegación and the Tables for facilitating the calculations of nautical astronomy.
Scientific career
Fields	Navigation, Astronomy, Mathematics
Institutions	Royal Society (1793). French Academy of Sciences.

Josef de Mendoza y Ríos (born in 1761, died in 1816) was a smart Spanish scientist. He was an astronomer and mathematician who lived in the 1700s and early 1800s. He became very famous for his important work on navigation, which is the science of guiding ships.

In 1787, Mendoza y Ríos published his first big work. It was a detailed book about how to navigate ships. He also created many special tables. These tables helped sailors easily calculate their ship's position at sea. They could figure out how far north or south they were (called latitude) using the sun. They could also find their east or west position (called longitude) by looking at the moon's distance from other stars.

He also made improvements to a special tool called the reflecting circle. This tool helped sailors measure angles accurately. In 1816, he was chosen as a member of the Royal Swedish Academy of Sciences. This was a great honor for his scientific achievements.

Biography

In 1787, Josef de Mendoza y Ríos published his first major book. It was a two-volume guide about the science and methods of navigation. This book became a very important resource for sailors and scientists at the time.

After writing his book, he suggested creating a special library for sea-related knowledge. This library was planned for Cádiz, a city in Spain. It eventually became known as the Depósito Hidrográfico, which is like a naval map and information center.

Mendoza y Ríos also created many useful tables for navigation. He used a new method he invented, sometimes called the haversine method. These tables made it much easier to do complex calculations needed for sailing.

His tables were mainly used to find a ship's latitude. Sailors could do this by measuring the sun's height twice and noting the time between measurements. His tables also helped find longitude using a method called lunar distances. This involved measuring the moon's distance from other celestial bodies.

He also improved a navigation tool called the reflecting circle. This tool was used to measure angles, which is crucial for finding a ship's position. In 1816, he was recognized for his work and became a foreign member of the Royal Swedish Academy of Sciences.

Here's a fun fact about how calculations were done back then. In 1815, while working on his famous Lunar Tables, he wrote a letter to a friend. He said he had so much work that he needed "four or five more calculators." Back then, a "calculator" was a person who did math by hand! This shows how much detailed work he put into his tables.

Honors

A place in Antarctica called Mendoza Cove is named after José de Mendoza y Ríos. This honors his important contributions to navigation and exploration.

See also

In Spanish: José de Mendoza y Ríos para niños

• Bowditch's American Practical Navigator
• Celestial navigation
• Haversine
• History of longitude
• Lunar distance (navigation)
• Marine sandglass
• Nautical almanac
• Navigational algorithms
• Sextant
• Reflecting instrument

Images for kids

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  Tratado de Navegacion, Volume 1.

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  Tables for facilitating the calculations of nautical astronomy.

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  Mendoza repeating circle, made around 1810 by Edward Troughton, London. On display at the Musée national de la Marine, Paris.