Henry Kater FRS, FRAS (16 April 1777 – 26 April 1835) was a British

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

descent.

Early life

He was born at

Bristol Bristol () is a City status in the United Kingdom, city, Ceremonial counties of England, ceremonial county and unitary authority in England. Situated on the River Avon, Bristol, River Avon, it is bordered by the ceremonial counties of Glouces ...

. At first he intended to study

law Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. It has been vario ...

; but he gave up the idea on his father's death in 1794. He entered the army, obtaining a commission in the

12th Regiment of Foot 1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length&nb ...

, then stationed in

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

, where he assisted

William Lambton Lieutenant-Colonel William Lambton, FRS (c. 1753 – 20 or 26 January 1823) was a British soldier, surveyor, and geographer who began a triangulation survey in 1800-1802 that was later called the Great Trigonometrical Survey of India. His init ...

in the

Great Trigonometric Survey The Great Trigonometrical Survey was a project that aimed to survey the entire Indian subcontinent with scientific precision. It was begun in 1802 by the British infantry officer William Lambton, under the auspices of the East India Company.G ...

. Failing health obliged him to return to England; and in 1808, then a lieutenant, he entered on a student career at the Senior Division of the new Royal Military College at

High Wycombe High Wycombe, often referred to as Wycombe ( ), is a market town in Buckinghamshire, England. Lying in the valley of the River Wye, Buckinghamshire, River Wye surrounded by the Chiltern Hills, it is west-northwest of Charing Cross in London, ...

. Shortly afterwards he was promoted to the rank of captain. In 1814 he retired on half-pay, and devoted the remainder of his life to scientific research.

Scientist

His first major contribution to science was the comparison of the merits of the Cassegrainian and

Gregorian telescope The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke. James Gregory was a contemporary of Isaac Newton. Both oft ...

s; Kater determined the latter to be an inferior design. His most substantial work was the invention of

Kater's pendulum A Kater's pendulum is a reversible free swinging pendulum invented by British physicist and army captain Henry Kater in 1817 for use as a gravimeter instrument to measure the local acceleration of gravity. Its advantage is that, unlike previous ...

, enabling the strength of gravity to be determined, first at

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

and subsequently at various stations throughout the country. As the inventor of the floating collimator, Kater rendered a service to practical

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

. He also published memoirs on British standards of length and mass; and in 1832 he published an account of his work on verifying the Russian standards of length. For these services to

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

he received in 1814 the decoration of the order of St. Anne; and the same year he was elected a

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural knowledge, including mathemati ...

. In 1826, he was elected a foreign member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for prom ...

. Kater was elected a Foreign Honorary Member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

in 1832. In 1833 he was elected a fellow of the

Royal Astronomical Society (Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NG ...

. He won the

Copley Medal The Copley Medal is an award given by the Royal Society, for "outstanding achievements in research in any branch of science". It alternates between the physical sciences or mathematics and the biological sciences. Given every year, the medal is t ...

in 1817 and the

Gold Medal of the Royal Astronomical Society The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...

in 1831. He is considered as the inventor of the

prismatic compass A prismatic compass is a navigation and surveying instrument which is extensively used to find out the bearing of the traversing and included angles between them, waypoints (an endpoint of the lcourse) and direction. Compass surveying is a typ ...

, patented a year later by Charles Schmalcalder. He also studied

compass needle A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with ...

s, his

Bakerian lecture The Bakerian Medal is one of the premier medals of the Royal Society that recognizes exceptional and outstanding science. It comes with a medal award and a prize lecture. The medalist is required to give a lecture on any topic related to physical ...

''On the Best Kind of Steel and Form for a Compass Needle''
Phil. Trans., 1821. containing the results of many experiments. The treatise on "Mechanics" in

Dionysius Lardner Professor Dionysius Lardner FRS FRSE (3 April 179329 April 1859) was an Irish scientific writer who popularised science and technology, and edited the 133-volume '' Cabinet Cyclopædia''. Early life in Dublin He was born in Dublin on 3 Apr ...

's '' Cabinet Cyclopedia'' was partly written by him; and his interest in more purely astronomical questions was shown by two papers in the '' Memoirs of the Royal Astronomical Society'' for 1831–1833 — one on an observation of

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

's outer ring, the other on a method of determining

longitude Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek let ...

by means of

lunar eclipse A lunar eclipse occurs when the Moon moves into the Earth's shadow. Such alignment occurs during an eclipse season, approximately every six months, during the full moon phase, when the Moon's orbital plane is closest to the plane of the Ear ...

Works

References

Notes

External links

Awarding of RAS gold medal

Obituaries

{{DEFAULTSORT:Kater, Henry 1777 births 1835 deaths 19th-century British astronomers English physicists Fellows of the American Academy of Arts and Sciences Fellows of the Royal Society Members of the Royal Swedish Academy of Sciences Scientists from Bristol Recipients of the Copley Medal Recipients of the Gold Medal of the Royal Astronomical Society 18th-century English people 19th-century English people Suffolk Regiment officers Military personnel from Bristol