Jesse Ramsden facts for kids
Quick facts for kids
Jesse Ramsden
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Mezzotint by J. Jones, 1790, after Robert Home. This, the only portrait of Ramsden shows him with the dividing engine in front of him and a great circle made for the Palermo Astronomical Observatory behind him. Ramsden never wore fur coats but the artist added it because the painting commemorated an order from the Empress of Russia that Ramsden had worked on.
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| Born | 6 October 1735 Salterhebble, Yorkshire, UK
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| Died | 5 November 1800 (aged 65) Brighton, Sussex
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| Nationality | British |
| Known for | Dividing engine Ramsden eyepiece Surveying instruments Optical telescopes |
| Awards | Copley Medal (1795) |
| Scientific career | |
| Fields | astronomical optics |
Jesse Ramsden was a clever British scientist and instrument maker who lived from 1735 to 1800. He became famous for inventing special machines called dividing engines. These machines helped create scientific tools that could measure angles and lengths with amazing accuracy.
Ramsden made many instruments for studying the stars (astronomy). His tools were especially important for sailors, who used them to figure out their location at sea. He also made surveying instruments, which were used to map land across the British Empire and beyond. You might still hear about the Ramsden eyepiece, a part of telescopes and microscopes that he invented.
Contents
Jesse Ramsden's Life
Jesse Ramsden was born on October 6, 1735, in Salterhebble, a small village in Yorkshire, England. His father, Thomas Ramsden, was an innkeeper.
Jesse went to a free school in Halifax from 1744 to 1747. When he was twelve, he moved to live with his uncle and studied mathematics. After finishing his training as a cloth-worker in Halifax, he moved to London in 1755. There, he first worked as a clerk in a cloth warehouse.
In 1758, Jesse started learning how to make mathematical instruments. He was so good at it that he opened his own business just four years later. The high quality and accuracy of his instruments quickly made him known as the best instrument maker in Europe. He held this reputation for the next forty years until his death.
In 1765, Jesse Ramsden married Sarah Dollond. Her father, John Dollond, was a famous maker of high-quality lenses. As part of their marriage, Ramsden received a share in Dollond's special patent for achromatic lenses. These lenses helped telescopes show clearer images without blurry colors.
Jesse and Sarah had two sons and two daughters, but only one son, John, lived past childhood. John later became a commander in the East India Company's navy.
Making Instruments Better
Ramsden's dividing engine was a game-changer. It allowed instruments to be made smaller without losing their accuracy. This was a huge step forward for science and navigation.
In 1777, the Board of Longitude bought the rights to a portable sextant (a navigation tool) that Ramsden designed. They paid him £300 for the design and another £315 so that other craftsmen could use his building plans. This helped spread his amazing inventions.
Jesse Ramsden was known for being a friendly person. However, he often made his customers angry because he was very slow in delivering their orders, especially for larger projects. For example, he took three years to deliver a special surveying tool called a theodolite to William Roy. This caused a public argument within the Royal Society. Ramsden's delays often came from his desire for perfection. He would keep improving his designs until they were absolutely flawless.
In 1786, Ramsden was chosen to be a member of the Royal Society, a very important group of scientists. He also received the Copley Medal in 1795. This award was given to him for all his "various inventions and improvements in philosophical instruments."
Jesse Ramsden's health began to fail in his later years. He moved to Brighton on the south coast, hoping the better climate would help him. However, he died there on November 5, 1800. His instrument-making business was taken over by his foreman, Matthew Berge. Many of Ramsden's apprentices, like William Cary, went on to start their own successful businesses. Others, like Edward Troughton, used Ramsden's ideas in their own designs.
Ramsden's Amazing Instruments
Dividing Engines
Jesse Ramsden created one of the first high-quality dividing engines. This machine was very important for making accurate circles on scientific instruments. These circles were used to measure angles precisely, and they started to replace older tools in observatories by the late 1700s. In 1777, he published a book explaining how his dividing engine worked.
Other Inventions
Ramsden also invented early electrostatic generators, which were machines that could create static electricity.
Surveying Instruments
Around 1785, Ramsden made a new, large theodolite for General William Roy. A theodolite is a tool used to measure angles in both horizontal and vertical planes. This particular one was used to measure the distances between London (Greenwich) and Paris. This important work helped create the basis for the first detailed maps of Britain, known as the Ordnance Survey.
Telescopes and Eyepieces
Ramsden is also famous for the achromatic eyepiece that is named after him. An eyepiece is the part of a telescope or microscope that you look through. His design used two special lenses placed a certain distance apart. This design had the advantage of allowing more space between the lens and your eye, making it more comfortable to use. It also allowed other parts, like sunshades, to be added easily.
The small circle of light you see when you hold an eyepiece up to the light is sometimes called the Ramsden disc in his honor.
In 1791, he finished building the Shuckburgh telescope, a large telescope mounted in a way that allowed it to easily track stars.
One of his most celebrated works was a huge 5-foot vertical circle, completed in 1789. This instrument was used by Giuseppe Piazzi at the Palermo Astronomical Observatory. Piazzi used it to create his catalogue of stars and, famously, to discover the dwarf planet Ceres on January 1, 1801.
Micrometers
Ramsden was also the first to successfully use a new way to read angles. This method involved using a tiny screw, called a micrometer screw, to measure the exact distance from a marker to the nearest division line on an instrument. This made measurements even more precise.
Honours
Ramsden Rock in Antarctica is named after Jesse Ramsden, honoring his contributions to science.
See also
In Spanish: Jesse Ramsden para niños
