Humphrey Lloyd
FRS FRSE
Fellowship of the Royal Society of Edinburgh (FRSE) is an award granted to individuals that the Royal Society of Edinburgh, Scotland's national academy of science and letters, judged to be "eminently distinguished in their subject". This soci ...
MRIA (1800–1881) was an Irish physicist. He was
Erasmus Smith's Professor of Natural and Experimental Philosophy at Trinity College Dublin (1831-1843) and much later Provost (1867–1881). Lloyd is known for experimentally verifying
conical refraction
Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, excluding any remnant of Newton's corpuscular the ...
, a theoretical prediction made by
William Rowan Hamilton
Sir William Rowan Hamilton Doctor of Law, LL.D, Doctor of Civil Law, DCL, Royal Irish Academy, MRIA, Royal Astronomical Society#Fellow, FRAS (3/4 August 1805 – 2 September 1865) was an Irish mathematician, astronomer, and physicist. He was the ...
about the way light is bent when travelling through a
biaxial crystal. He was 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 science, natural knowledge, incl ...
, and President of both the
British Association
The British Science Association (BSA) is a charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Science (BA). The current Chie ...
and the
Royal Irish Academy
The Royal Irish Academy (RIA; ga, Acadamh Ríoga na hÉireann), based in Dublin, is an academic body that promotes study in the sciences, humanities and social sciences. It is Ireland's premier List of Irish learned societies, learned socie ...
.
Early life
The eldest son of the Rev.
Bartholomew Lloyd
Bartholomew Lloyd (1772–1837) was an Irish mathematician and academic whose entire career was spent at Trinity College Dublin. As Erasmus Smith's Professor of Mathematics there, he promoted significant curricular reforms, including the introdu ...
, and his wife, Eleanor McLaughlin, he was born in Dublin on 16 April 1800. His father had also served as
and Provost of TCD.
After early education at Mr. White's school in Dublin, he entered
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 1815, first out of 63 competitors in the entrance examination. He was
elected a Scholar in 1818, and graduated B.A. in 1819, taking first place and the gold medal for science, and proceeding M.A. in 1827, and D.D. in 1840. He became a junior fellow in 1824, and a senior fellow in 1843.
Scientific career
Lloyd in 1831 succeeded his father as Erasmus Smith's Professor of Natural and Experimental Philosophy. At the meeting of the
British Association
The British Science Association (BSA) is a charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Science (BA). The current Chie ...
in 1833 he spoke on his establishment by experiment of the existence of conical refraction in biaxial crystals, in conformity with the theory of William Rowan Hamilton. He also succeeded in establishing experimentally the law by which the
polarisation of the rays composing the luminous cone is governed. Shortly after, by means of an
experiment
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into Causality, cause-and-effect by demonstrating what outcome oc ...
on the interference of light proceeding directly from a luminous source, with light coming from the same source but reflected at a very high angle of incidence from a plane surface, he contributed to the theory of reflected light. A letter from
Sir David Brewster
Sir David Brewster KH PRSE FRS FSA Scot FSSA MICE (11 December 178110 February 1868) was a British scientist, inventor, author, and academic administrator. In science he is principally remembered for his experimental work in physical optics, ...
led him to turn his attention to the phenomena of light incident on thin plates. In 1841 he submitted a communication on the subject to the British Association, and in 1859 he described his investigation of the phenomena to the
Royal Irish Academy
The Royal Irish Academy (RIA; ga, Acadamh Ríoga na hÉireann), based in Dublin, is an academic body that promotes study in the sciences, humanities and social sciences. It is Ireland's premier List of Irish learned societies, learned socie ...
(see ''Transactions'', vol. xxiv.)
When the magnetic observatory of Trinity College Dublin, was established under the auspices of his father, it was placed in Lloyd's charge, and the instruments for it were devised by him and constructed under his superintendence. He was a member of the committee of the British Association lobbying government to improve knowledge of
terrestrial magnetism
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic fi ...
by establishing observing stations. He prepared the instructions for the observatories, and the officers appointed to take charge of them were trained by him in Dublin.
Later life
From 1846 to 1851 Lloyd was president of the
Royal Irish Academy
The Royal Irish Academy (RIA; ga, Acadamh Ríoga na hÉireann), based in Dublin, is an academic body that promotes study in the sciences, humanities and social sciences. It is Ireland's premier List of Irish learned societies, learned socie ...
, who in 1862 awarded him their
Cunningham gold medal. He resigned his chair of natural philosophy in 1843, on his accession to a senior fellowship in Trinity College. In 1862 he became vice-provost, and in 1867 was appointed provost, in succession to
Richard MacDonnell. He was president of the British Association in 1857, when it met in Dublin, and delivered an inaugural address, which was published, in which he gave a sketch of the recent progress made in astronomy, terrestrial magnetism, and other branches of science.
Lloyd was a leading member of the general synod of the Irish church which came into existence on
Irish disestablishment
The Irish Church Act 1869 (32 & 33 Vict. c. 42) was an Act of the Parliament of the United Kingdom which separated the Church of Ireland from the Church of England and disestablished the former, a body that commanded the adherence of a small min ...
, and took part in its committee for the revision of the prayer-book. He died in the provost's house, Dublin, 17 January 1881.
Awards and honours
Lloyd was a fellow of the Royal Societies of London and Edinburgh, and an honorary member of many other learned societies of Europe and America. He was elected as a member to the
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...
in 1839.
In 1855 the university of Oxford conferred on him the degree of D.C.L., and in 1874 the emperor of Germany the order ''
Pour le Mérite
The ' (; , ) is an order of merit (german: Verdienstorden) established in 1740 by Frederick the Great, King Frederick II of Prussia. The was awarded as both a military and civil honour and ranked, along with the Order of the Black Eagle, the Or ...
''. A bust of him, by
Albert Bruce Joy
Albert Bruce-Joy (21 August 1842 – 22 July 1924) was an Irish sculptor working in England. His original surname was Joy but he became known under his hyphenated name Bruce-Joy later in life.
He was the brother of the painter George W. Joy.
...
, was placed in the library of Trinity College in 1892.
Works
In 1834 Lloyd furnished the British Association, at its request, with a report on ''The Progress and Present State of Physical Optics'' (see Report for 1834). Papers which he wrote on terrestrial magnetism and other subjects are in the ''Reports'' of the British Association and in the ''Transactions'' and ''Proceedings'' of the Royal Irish Academy. Besides tracts, his other published works were:
* ''A Treatise on Light and Vision'', London, 1831.
* ''Two Introductory Lectures on Physical and Mechanical Science'', London, 1834.
* ''Lectures on the Wave-theory of Light'', two parts, Dublin, 1836 and 1841; republished, London, 1857, as ''Elementary Treatise on the Wave-theory of Light''.
* ''Account of the Magnetic Observatory at Dublin, and of the Instruments and Methods of Observation employed there'', London, 1842.
* ''An Account of the Method of Determining the Total Intensity of the Earth's Magnetic Force in Absolute Measure'', London, 1848.
* ''The Elements of Optics'', Dublin, 1849.
* ''Address delivered at the opening meeting of the British Association for the Advancement of Science, held at Dublin 26 Aug 1857'', Dublin, 1857.
* ''Is it a Sin? An Inquiry into the Lawfulness of Complying with the Rule of the National Board relative to Religious Instruction'', published anonymously, Dublin, 1860.
* ''The Climate of Ireland and the Currents of the Atlantic'', a lecture, Dublin, 1865.
* ''Observations made at the Magnetical and Meteorological Observatory at Trinity College, Dublin'', Dublin, 1865.
* ''The University of Dublin in its Relations to the several Religious Communities'', anonymous, Dublin, 1868.
* ''The Doctrine of Absolutism'', Dublin, 1871.
* ''Treatise on Magnetism, General and Terrestrial'', London, 1874.
* ''Miscellaneous Papers connected with Physical Science'', London, 1877.
Family
Lloyd married, in July 1840, Dorothea, only daughter of the Rev. James Bulwer, rector of Hunworth-cum-Stody, Norfolk. He had no children.
Notes
References
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External links
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{{DEFAULTSORT:Lloyd, Humphrey
1800 births
1881 deaths
Alumni of Trinity College Dublin
Fellows of the Royal Society
Fellows of Trinity College Dublin
Honorary Fellows of the Royal Society of Edinburgh
Irish physicists
Magneticians
Members of the Royal Irish Academy
Optical physicists
Scientists from Dublin (city)
Provosts of Trinity College Dublin
Recipients of the Pour le Mérite (civil class)
Scholars of Trinity College Dublin