William Fishburn Donkin
Encyclopedia
William Fishburn Donkin (15 February 1814 – 15 November 1869) was an astronomer and mathematician, and Savilian Professor of Astronomy at the University of Oxford
University of Oxford
The University of Oxford is a university located in Oxford, United Kingdom. It is the second-oldest surviving university in the world and the oldest in the English-speaking world. Although its exact date of foundation is unclear, there is evidence of teaching as far back as 1096...

.

Private life

He was born at Bishop Burton
Bishop Burton
Bishop Burton is a village and civil parish in the East Riding of Yorkshire, England. It lies on the A1079 road approximately to the west of the market town of Beverley.According to the 2001 UK census, Bishop Burton parish had a population of 628....

, Yorkshire, the son of Thomas Donkin, Land Agent, and was educated at St Peter's School, York
St Peter's School, York
St Peter's School is a co-educational independent boarding and day school located in the English City of York, with extensive grounds on the banks of the River Ouse...

 and (from 1832) St Edmund Hall, Oxford
St Edmund Hall, Oxford
St Edmund Hall is one of the constituent colleges of the University of Oxford in England. Better known within the University by its nickname, "Teddy Hall", the college has a claim to being "the oldest academical society for the education of undergraduates in any university"...

  He was a nephew of Bryan Donkin
Bryan Donkin
Bryan Donkin was an English engineer and industrialist. Of his six sons, John, Bryan, and Thomas also became engineers.-Early life:Born in Sandoe, Northumberland, his father was a surveyor and land agent...

.

In 1844 he married Harriet, the third daughter of the Revd John Hawtrey of Guernsey. They had six children: William Frederick (an explorer and mountaineer), Arthur (assistant master, Rugby School
Rugby School
Rugby School is a co-educational day and boarding school located in the town of Rugby, Warwickshire, England. It is one of the oldest independent schools in Britain.-History:...

), Alice Emily (a painter), Alfred, Edward and Reginald.

He was a contemporary of Charles Dodgson (Lewis Carroll
Lewis Carroll
Charles Lutwidge Dodgson , better known by the pseudonym Lewis Carroll , was an English author, mathematician, logician, Anglican deacon and photographer. His most famous writings are Alice's Adventures in Wonderland and its sequel Through the Looking-Glass, as well as the poems "The Hunting of the...

).

Donkin's constitution was always delicate, and failing health compelled him to live much abroad during the latter part of his life. He died at his home in Broad Street, Oxford.

Academic life

From an early age Donkin showed talent for languages, mathematics, and music. In 1834 he won a classical scholarship at University College, Oxford
University College, Oxford
.University College , is a constituent college of the University of Oxford in England. As of 2009 the college had an estimated financial endowment of £110m...

, where in 1836 he obtained a double first class in classics and mathematics (BA 1836, MA 1839). In 1837 he won the mathematical and Johnson mathematical scholarships.

He was a fellow of University College, and for about six years was a mathematical lecturer at St Edmund Hall. During this period he wrote an early statistical essay for the Ashmolean Society, the ‘Essay on the theory of the combination of observations’. He also contributed some papers on Greek music to Dr Smith's Dictionary of Antiquities.

In 1842 Donkin was elected Savilian Professor of Astronomy, a post which he held for the remainder of his life. That year he was elected a Fellow of the Royal Society and the Royal Astronomical Society
Royal Astronomical Society
The Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...

.

Between 1850 and 1860 Donkin contributed several important papers to the Philosophical Transactions, including ‘On a class of differential equation
Differential equation
A differential equation is a mathematical equation for an unknown function of one or several variables that relates the values of the function itself and its derivatives of various orders...

s, including those which occur in dynamical problems’ (PTRS, 144, 1854) and ‘The equation of Laplace's functions’ (PTRS, 147, 1857). In these and other papers he drew upon W. R. Hamilton's theory of quaternion
Quaternion
In mathematics, the quaternions are a number system that extends the complex numbers. They were first described by Irish mathematician Sir William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space...

s. He also deployed the symbolic methods of solving differential equations widely used by English mathematicians at the time; a major figure was George Boole
George Boole
George Boole was an English mathematician and philosopher.As the inventor of Boolean logic—the basis of modern digital computer logic—Boole is regarded in hindsight as a founder of the field of computer science. Boole said,...

, who published some of Donkin's results in his Treatise on Differential Equations (1859). They included new ways of solving Laplace's equation
Laplace's equation
In mathematics, Laplace's equation is a second-order partial differential equation named after Pierre-Simon Laplace who first studied its properties. This is often written as:where ∆ = ∇² is the Laplace operator and \varphi is a scalar function...

, and also an important equation due to Laplace concerning potentials of a nearly spherical spheroid (such as the earth). He and Boole also exchanged ideas on methods of computation in probability theory
Probability theory
Probability theory is the branch of mathematics concerned with analysis of random phenomena. The central objects of probability theory are random variables, stochastic processes, and events: mathematical abstractions of non-deterministic events or measured quantities that may either be single...

. In 1861 he read an important paper to the Royal Astronomical Society
Royal Astronomical Society
The Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...

 entitled ‘The secular acceleration of the moon's mean motion’ (printed in the society's Monthly Notices for 1861). He was also a contributor to the Philosophical Magazine, his last paper in which, ‘Note on certain statements in elementary works concerning the specific heat of gases’, appeared in 1864.

Donkin's acquaintance with practical and theoretical music
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...

 was very thorough. His work on acoustics
Acoustics
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...

, intended to be his opus magnum, was commenced in 1867, and the fragment of it which he completed was published, after his death, in 1870. Basing his mathematical treatment on Fourier series
Fourier series
In mathematics, a Fourier series decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions, namely sines and cosines...

, he covered transverse and lateral vibrations of strings and rods, and free and forced oscillation
Oscillation
Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...

s. He also examined the composition of the musical scale
Musical scale
In music, a scale is a sequence of musical notes in ascending and descending order. Most commonly, especially in the context of the common practice period, the notes of a scale will belong to a single key, thus providing material for or being used to conveniently represent part or all of a musical...

, and had intended to present musical theory and practice in a third part. The second part would have treated elastic membranes, plates and solids, and the mathematical theory of sound. Although incomplete, his book was the principal work in English on this topic until Lord Rayleigh's Theory of Sound appeared in two volumes in 1877 and 1878. Among other interests, Donkin also corresponded on geometrical problems with William Spottiswoode
William Spottiswoode
William Spottiswoode FRS was an English mathematician and physicist. He was President of the Royal Society from 1878 to 1883.-Early life:...

.

Publications

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