16 Facts About Jesse Ramsden

Jesse Ramsden FRS FRSE was a British mathematician, astronomical and scientific instrument maker.

Jesse Ramsden's reputation was built on the engraving and design of dividing engines which allowed high accuracy measurements of angles and lengths in instruments.

Jesse Ramsden produced instruments for astronomy that were especially well known for maritime use where they were needed for the measurement of latitudes and for his surveying instruments which were widely used for cartography and land survey both across the British Empire and outside.

Jesse Ramsden was born at Salterhebble, Halifax, West Riding of Yorkshire, England the son of Thomas Jesse Ramsden, an innkeeper and his wife Abigail nee Flather.

In 1765, Jesse Ramsden married Sarah Dollond, daughter of John Dollond, the famous maker of high quality lenses and optical instruments.

Jesse Ramsden received a share in Dollond's patent achromatic lens as dowry.

In 1773, Jesse Ramsden moved to 199 Piccadilly but Sarah and her son lived at Haymarket at a home belonging to her father's family.

Jesse Ramsden's dividing engine allowed instruments to be made smaller without loss of measurement accuracy.

Jesse Ramsden was of a genial disposition, but at the same time infuriated his clients with his tardiness in delivering their purchases, particularly of larger commissions.

Jesse Ramsden was elected to the Royal Society in 1786 and to the Royal Society of Edinburgh in 1798.

Jesse Ramsden's health began to fail and he traveled to Brighton on the south coast to try to benefit from its better climate; he died there on 5 November 1800.

Jesse Ramsden published a Description of an Engine for dividing Mathematical Instruments in 1777.

Jesse Ramsden built an early plate electrostatic generator in 1768.

Jesse Ramsden is responsible for the achromatic eyepiece named after him.

Jesse Ramsden's most celebrated work was a 5-feet vertical circle, which was finished in 1789 and was used by Giuseppe Piazzi at the Palermo Astronomical Observatory in constructing his catalogue of stars and in the discovery of the dwarf planet Ceres on 1 January 1801.

Jesse Ramsden was the first to carry out in practice a method of reading off angles by measuring the distance of the index from the nearest division line by means of a micrometer screw which moves one or two fine threads placed in the focus of a microscope.