Reverend Charles Pritchard (29 February 1808 – 28 May 1893) was a British

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

, clergyman, and educational reformer. He founded the

Clapham Clapham () is a suburb in south west London, England, lying mostly within the London Borough of Lambeth, but with some areas (most notably Clapham Common) extending into the neighbouring London Borough of Wandsworth. History Early history ...

Grammar School in 1834 and included sciences in the curriculum. A chapel was erected in 1846.

Biography

He was born at

Alberbury, Shropshire Alberbury is a village in Shropshire, England, west of Shrewsbury on the B4393 road which travels from Ford to Lake Vyrnwy. It is on to the England-Wales border, marked by Prince's Oak. The River Severn runs just north of the village, and mos ...

and attended Poplar Academy where he was taught by John Stock, the progressive educationalist. Pritchard later described his studies as consisting of "a systematic course of instruction relating to physical phenomena". At sixteen he was enrolled as a

sizar At Trinity College, Dublin and the University of Cambridge, a sizar is an undergraduate who receives some form of assistance such as meals, lower fees or lodging during his or her period of study, in some cases in return for doing a defined jo ...

St John's College, Cambridge St John's College is a constituent college of the University of Cambridge founded by the Tudor matriarch Lady Margaret Beaufort. In constitutional terms, the college is a charitable corporation established by a charter dated 9 April 1511. The ...

, graduating in 1830 as fourth wrangler. In 1832 he was elected a fellow of his college, and in the following year he was ordained, and became head of a private school at

Stockwell Stockwell is a district in south west London, part of the London Borough of Lambeth, England. It is situated south of Charing Cross. Battersea, Brixton, Clapham, South Lambeth, Oval and Kennington all border Stockwell. History The name ...

. From 1834 to 1862 he was headmaster of

grammar school A grammar school is one of several different types of school in the history of education in the United Kingdom and other English-speaking countries, originally a school teaching Latin, but more recently an academically oriented secondary school ...

. He then retired to

Freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does incl ...

, in the

Isle of Wight The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Is ...

, and took an active interest in the affairs of the

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

, of which he became honorary secretary in 1862 and president in 1866. His sister, Margaret died this same year. His career as a professional astronomer began in 1870, when he was elected

Savilian professor of astronomy The position of Savilian Professor of Astronomy was established at the University of Oxford in 1619. It was founded (at the same time as the Savilian Professorship of Geometry) by Sir Henry Savile, a mathematician and classical scholar who was ...

at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

. At his request the university decided to build a fine equatorial

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

for the instruction of his class and for purposes of research, a scheme which, as a result of Warren de la Rue's munificent gift of instruments from his private observatory at Cranford, expanded into the establishment of the new university

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. ...

. By De la Rue's advice, Pritchard began his career there with a determination of the physical

libration In lunar astronomy, libration is the wagging or wavering of the Moon perceived by Earth-bound observers and caused by changes in their perspective. It permits an observer to see slightly different hemispheres of the surface at different tim ...

of the

moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

, or the

nutation Nutation () is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behaviour of a mechanism. In an appropriate reference frame ...

of its axis. In 1882 Pritchard commenced a systematic study of stellar

photometry Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electro ...

. For this purpose he employed an instrument known as the "

wedge photometer A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by conver ...

", with which he measured the relative brightness of 2,784 stars between the

North Pole The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Ma ...

and about -10°

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of th ...

. The results were published in 1885 in his ''Uranometria Nova Oxoniensis'', and their importance was recognized by the bestowal in 1886 upon him, conjointly with Professor Pickering, of 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 ...

. He then decided to experiment with applying photography to the determination of

stellar parallax Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects, and a basis for determining (through trigonometry) the distance of the object. Created by the different orbital p ...

. With the object of testing the capabilities of the method, he took for his first essay the well-known star

61 Cygni 61 Cygni is a binary star system in the constellation Cygnus, consisting of a pair of K-type dwarf stars that orbit each other in a period of about 659 years. Of apparent magnitude 5.20 and 6.05, respectively, they can be seen ...

, and his results agreed so well with those previously attained that he undertook the systematic measurement of the parallaxes of second-magnitude stars, and published the outcome in the third and fourth volumes of the ''Publications of the Oxford University Observatory''. Although some lurking errors impaired the authority of the concluded parallaxes this work ranks as a valuable contribution to astronomy, since it showed the possibility of employing photography in such delicate investigations. When an international survey of the heavens was proposed, the zone between 25° and 31° north declination was allotted to him, and at the time of his death some progress had been made in recording its included stars. Pritchard became a fellow of

New College, Oxford New College is one of the constituent colleges of the University of Oxford in the United Kingdom. Founded in 1379 by William of Wykeham in conjunction with Winchester College as its feeder school, New College is one of the oldest colleges at ...

, in 1883, and an honorary fellow of

, in 1886. He was elected a fellow of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

in 1840, and in 1892 was awarded one of the royal medals for his work on

and stellar

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby object ...

Works

* *
Occasional thoughts of an astronomer on nature and revelation
' (1889) *
Modern science and natural religion
' (1874)

References

*''Proc. Roy. Soc.'' liv. 3 *''Astr. and Astrophysics'', xii. 592 *J. Foster, ''Oxford Men and their Colleges'', p. 206 *''Hist. Register of the Univ. of Oxford'', p. 95 *''

The Times ''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper '' The Sunday Times'' ( ...

'' (30 May 1893) *C. J. Robinson's ''Register of Merchant Taylors' School'', ii. 210 *''Charles Pritchard, D.D., Memoirs of his Life'', by Ada Pritchard (London, 1897). *

External links

Awarding of RAS gold medal
*

Obituaries

{{DEFAULTSORT:Pritchard, Charles 1808 births 1893 deaths Scientists from Shropshire Alumni of St John's College, Cambridge British Christians 19th-century British astronomers Fellows of the Royal Society Fellows of New College, Oxford Royal Medal winners Recipients of the Gold Medal of the Royal Astronomical Society Savilian Professors of Astronomy Presidents of the Royal Astronomical Society