John Herapath (30 May 1790 – 24 February 1868) was an English

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 ...

who gave a partial account of the

kinetic theory of gases The kinetic theory of gases is a simple classical model of the thermodynamic behavior of gases. Its introduction allowed many principal concepts of thermodynamics to be established. It treats a gas as composed of numerous particles, too small ...

in 1820 though it was neglected by the scientific community at the time. He was the cousin of William Herapath, the chemist and William Bird Herapath, the physician who discovered

herapathite Herapathite, or iodoquinine sulfate, is a chemical compound whose crystals are dichroic and thus can be used for polarizing light. Its formation was investigated by 1852 by William Bird Herapath, a Bristol surgeon and chemist, after his pupil (M ...

. In 1847 he published an early textbook on

mathematical physics Mathematical physics is the development of mathematics, mathematical methods for application to problems in physics. The ''Journal of Mathematical Physics'' defines the field as "the application of mathematics to problems in physics and the de ...

Kinetic theory

Herapath's scientific interests started with an attempt to provide a mechanistic explanation for

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

. Motivated by his search for a mechanical explanation of gravitation, he started to consider how a system of colliding particles could give rise to ''

action at a distance Action at a distance is the concept in physics that an object's motion (physics), motion can be affected by another object without the two being in Contact mechanics, physical contact; that is, it is the concept of the non-local interaction of ob ...

''. In considering the effect of the high

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

s near the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

on his ''gravific particles'' he was led to a relationship between temperature and particle

velocity Velocity is a measurement of speed in a certain direction of motion. It is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of physical objects. Velocity is a vector (geometry), vector Physical q ...

. Herapath postulated that the

momentum In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...

of a particle in a

gas Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...

is a measure of the

absolute temperature Thermodynamic temperature, also known as absolute temperature, is a physical quantity which measures temperature starting from absolute zero, the point at which particles have minimal thermal motion. Thermodynamic temperature is typically expres ...

of the gas. He used momentum, rather than the

kinetic energy In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Rober ...

on which the later established theory is based, as it seemed to him to avoid some difficulties around whether

elastic collision In physics, an elastic collision occurs between two physical objects in which the total kinetic energy of the two bodies remains the same. In an ideal, perfectly elastic collision, there is no net loss of kinetic energy into other forms such a ...

s were possible between indivisible

atom Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished fr ...

s. Apparently ignorant of

Daniel Bernoulli Daniel Bernoulli ( ; ; – 27 March 1782) was a Swiss people, Swiss-France, French mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family from Basel. He is particularly remembered for his applicati ...

's work, he was led to the incorrect, but suggestive, relationship that expresses the product of

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

''P'' and

volume Volume is a measure of regions in three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch) ...

''V'' as proportional to the square of his ''true temperature''. The correct relationship is proportional to the absolute temperature, not its square, the error arising from his identification of momentum, rather than

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

, with temperature. * * He submitted his ideas in a paper to 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 1820 where it was

peer review Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (:wiktionary:peer#Etymology 2, peers). It functions as a form of self-regulation by qualified members of a profession within the ...

ed by Sir

Humphry Davy Sir Humphry Davy, 1st Baronet (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several Chemical element, e ...

. Davy had already sympathised with the view that heat was associated with

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

motion rather than with

Joseph Black Joseph Black (16 April 1728 – 6 December 1799) was a British physicist and chemist, known for his discoveries of magnesium, latent heat, specific heat, and carbon dioxide. He was Professor of Anatomy and Chemistry at the University of Glasgow ...

caloric theory The caloric theory is an obsolete scientific theory that heat consists of a self-repellent fluid called caloric that flows from hotter bodies to colder bodies. Caloric was also thought of as a weightless gas that could pass in and out of pores ...

heat In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...

but he rejected Herapath's paper with some coolness, uncomfortable with the implication that there was an

absolute zero Absolute zero is the lowest possible temperature, a state at which a system's internal energy, and in ideal cases entropy, reach their minimum values. The absolute zero is defined as 0 K on the Kelvin scale, equivalent to −273.15 ° ...

of temperature at which all

motion In physics, motion is when an object changes its position with respect to a reference point in a given time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an o ...

ceased. Davy may also have had some distaste for the mechanistic Newtonian picture, influenced as he was by the more

holistic Holism is the interdisciplinary idea that systems possess properties as wholes apart from the properties of their component parts. Julian Tudor Hart (2010''The Political Economy of Health Care''pp.106, 258 The aphorism "The whole is greater than t ...

philosophy Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...

of the

Romantic movement Romanticism (also known as the Romantic movement or Romantic era) was an artistic and intellectual movement that originated in Europe towards the end of the 18th century. The purpose of the movement was to advocate for the importance of subjec ...

. *

James Prescott Joule James Prescott Joule (; 24 December 1818 11 October 1889) was an English physicist. Joule studied the nature of heat and discovered its relationship to mechanical work. This led to the law of conservation of energy, which in turn led to the ...

presented a short account of the work in 1848. Meanwhile, Herapath maintained a campaign against Davy and the Royal Society in the correspondence pages of ''

The Times ''The Times'' is a British Newspaper#Daily, daily Newspaper#National, national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its modern name on 1 January 1788. ''The Times'' and its si ...

'' newspaper.

Great Comet of 1831

On 7 January 1831 Herapath was on

Hounslow Heath Hounslow Heath is a local nature reserve in the London Borough of Hounslow and at a point borders London Borough of Richmond upon Thames, Richmond upon Thames. The public open space, which covers , is all that remains of the historic Hounslow He ...

when he sighted a

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

. Due to its brilliance, it is one of the

great comet A great comet is a comet that becomes exceptionally bright. There is no official definition; often the term is attached to comets such as Halley's Comet, which during certain appearances are bright enough to be noticed by casual observers who ar ...

s. The comet was also observed by Thomas Glanville Taylor at the Madras Observatory.

''Railway Journal''

In 1835 Herapath became editor of ''The Railway Magazine'', which underwent four changes of name during the boom years of railways to become Herapath's ''Railway Journal'' in January 1894. It is now published as ''

Railway Gazette International ''Railway Gazette International'' is a British monthly business magazine and news website covering the railway, metro, light rail and tram industries worldwide. Available by annual subscription, the magazine is read in over 140 countries by tran ...

'', and is not to be confused with ''

The Railway Magazine ''The Railway Magazine'' is a monthly United Kingdom, British railway magazine, aimed at the Railfan, railway enthusiast market, that has been published in London since July 1897. it was, for three years running, the railway magazine with the ...

'' which commenced publication in 1897. This gave him some limited opportunity to publish his scientific ideas. In 1836, he published a calculation of the

mean A mean is a quantity representing the "center" of a collection of numbers and is intermediate to the extreme values of the set of numbers. There are several kinds of means (or "measures of central tendency") in mathematics, especially in statist ...

molecular

speed In kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a non-negative scalar quantity. Intro ...

in a gas based on his kinetic theory and hence the

speed of sound The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elasticity (solid mechanics), elastic medium. More simply, the speed of sound is how fast vibrations travel. At , the speed of sound in a ...

. Joule reproduced his results but is usually incorrectly credited as the originator. The name changes were – *''Railway magazine'' May 1835-Feb. 1836 *''Railway magazine and annals of science'' Mar. 1836 – Aug. 1839 *''Railway magazine and steam navigation journal'' Mar. – Aug. 1839 *''Railway magazine and commercial journal'' 17 Aug. 1839 – Dec. 1840 *''Herapath's railway magazine, commercial journal, and scientific review'' Jan. 1841 – Dec. 1842 *''Herapath's railway and commercial journal'' Jan. 1843 – Dec. 1845 The editions from 1839 to 1895 can be viewed in the

National Archives National archives are the archives of a country. The concept evolved in various nations at the dawn of modernity based on the impact of nationalism upon bureaucratic processes of paperwork retention. Conceptual development From the Middle Ages i ...

National Archives list of records held 1839–1895
/ref> and several issues are also available as e-books, e.g
18371836–1839
and several in Google books.

Later work

He revised his theories in the 1840s, largely based on the experimental work of Thomas Graham and

Henri Victor Regnault Henri Victor Regnault (21 July 1810 – 19 January 1878) was a French chemist and physicist best known for his careful measurements of the thermal properties of gases. He was an early thermodynamicist and was mentor to William Thomson in ...

. * 1847
Mathematical Physics; or, the Mathematical Principles of Natural Philosophy, the causes of heat, gaseous elasticity, gravitation, and other great phenomena of nature
Whittaker and company via

HathiTrust HathiTrust Digital Library is a large-scale collaborative repository of digital content from research libraries. Its holdings include content digitized via Google Books and the Internet Archive digitization initiatives, as well as content digit ...

Herapath died at Catford Bridge,

Lewisham Lewisham ( ) is an area of southeast London, England, south of Charing Cross. It is the principal area of the London Borough of Lewisham, and was within the Historic counties of England, historic county of Kent until 1889. It is identified in ...

on 24 February 1868 and was buried at

West Norwood Cemetery West Norwood Cemetery is a rural cemetery in West Norwood in London, England. It was also known as the South Metropolitan Cemetery. One of the first private landscaped cemeteries in London, it is one of the " Magnificent Seven" cemeteries of ...

References

External links

* Dave Levermore (2001
Neglected Pioneers: John Herapath
from

University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public land-grant research university in College Park, Maryland, United States. Founded in 1856, UMD is the flagship institution of the Univ ...