Frederick Thomas Trouton
FRS (; 24 November 1863 – 21 September 1922) was an Irish
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 ...
known for
Trouton's rule and experiments to detect the Earth's motion through the
luminiferous aether.
Life and work
Trouton was born in
Dublin
Dublin (; , or ) is the capital and largest city of Ireland. On a bay at the mouth of the River Liffey, it is in the province of Leinster, bordered on the south by the Dublin Mountains, a part of the Wicklow Mountains range. At the 2016 ...
on 24 November 1863, the youngest son of the wealthy and prominent Thomas Trouton. He attended
Royal School Dungannon
The Royal School is a mixed boarding school located in Dungannon, County Tyrone, Northern Ireland. It was one of a number of 'free schools' created by James I (otherwise known as James VI of Scotland) in 1608 to provide an education to the son ...
and went on to
Trinity College, Dublin
, name_Latin = Collegium Sanctae et Individuae Trinitatis Reginae Elizabethae juxta Dublin
, motto = ''Perpetuis futuris temporibus duraturam'' (Latin)
, motto_lang = la
, motto_English = It will last i ...
in 1884, where he studied engineering and physical science. While still an undergraduate student, Trouton observed a relationship between
boiling points and
energies of vaporisations, which he presented in two short papers. He found the change of entropy per mole for vaporisation at a boiling point is constant, or expressed mathematically ΔS
m,vap = 10.5 R (where R is the
ideal gas constant
The molar gas constant (also known as the gas constant, universal gas constant, or ideal gas constant) is denoted by the symbol or . It is the molar equivalent to the Boltzmann constant, expressed in units of energy per temperature increment per ...
). This became known as
Trouton's rule and, despite having some exceptions, is used to estimate the
enthalpy
Enthalpy , a property of a thermodynamic system, is the sum of the system's internal energy and the product of its pressure and volume. It is a state function used in many measurements in chemical, biological, and physical systems at a constant ...
of vaporisation of liquids whose boiling points are known. Trouton himself belittled his discovery as it was merely the result of an afternoon's manipulation of data from a book of tables. Before graduating he also took a leading role in
surveying
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ...
for a railway.
Trouton graduated Master of Arts and
Doctor of Science
Doctor of Science ( la, links=no, Scientiae Doctor), usually abbreviated Sc.D., D.Sc., S.D., or D.S., is an academic research degree awarded in a number of countries throughout the world. In some countries, "Doctor of Science" is the degree used f ...
in 1884, and was immediately appointed assistant to the professor of experimental physics,
George Francis FitzGerald. They collaborated on many experiments and became good friends; FitzGerald's influence can be seen in much of Trouton's early work.
Trouton 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 June 1897.
His application citation read: "''Discovered the law connecting the latent heat of vaporisation and molecular weights of bodies known as "Trouton's law" and experimentally determined the directions of vibration of electric and inaquatic force in plane polarised light. He has made other important observations on the phase of secondary waves and on the influence of the size of the reflector in Hertz's equipment''."
A 1902 appointment as Quain Professor of Physics at
University College London
, mottoeng = Let all come who by merit deserve the most reward
, established =
, type = Public research university
, endowment = £143 million (2020)
, budget = ...
led to a 12-year career of experimental physics, including work on the Trouton-Rankine experiment. He received an
OBE in 1918.
Trouton married Anne Maria Fowler in 1887 and they had four sons and three daughters. Their first two sons, Eric and Desmond, were killed in
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
. He became severely ill in 1912 and an operation in 1914 left him paralysed in the lower limbs and caused his retirement. Despite this, he retained the wit and charm he was known for. After retiring, Trouton lived in
Tilford, Surrey, and then
Downe in Kent where he died on 21 September 1922.
References
{{DEFAULTSORT:Trouton, Frederick Thomas
Irish physicists
1863 births
1922 deaths
Alumni of Trinity College Dublin
Scientists from Dublin (city)
People educated at the Royal School Dungannon
Fellows of the Royal Society
Academics of University College London