seamus dubhghaill

Promoting Irish Culture and History from Little Rock, Arkansas, USA

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Birth of Mathematician William Rowan Hamilton

william-rowan-hamiltonSir William Rowan Hamilton, Irish mathematician who makes important contributions to classical mechanics, optics, and algebra, is born in Dublin on August 4, 1805.

Hamilton is the fourth of nine children born to Sarah Hutton (1780–1817) and Archibald Hamilton (1778–1819). He is part of a small but well-regarded school of mathematicians associated with Trinity College, Dublin, which he enters at age eighteen. He is said to have shown immense talent at a very early age. Astronomer Bishop Dr. John Brinkley remarks of the 18-year-old Hamilton, “This young man, I do not say will be, but is, the first mathematician of his age.”

Trinity College awards him two Optimes, or off-the-chart grades. He studies both classics and mathematics, and is appointed Professor of Astronomy just prior to his graduation. He then takes up residence at Dunsink Observatory where he spends the rest of his life.

Although Hamilton regards himself as a pure mathematician rather than a physicist, his work is of major importance to physics, particularly his reformulation of Newtonian mechanics, now called Hamiltonian mechanics. This work has proven central to the modern study of classical field theories such as electromagnetism, and to the development of quantum mechanics. In pure mathematics, he is best known as the inventor of quaternions.

Hamilton’s scientific career includes the study of geometrical optics, classical mechanics, adaptation of dynamic methods in optical systems, applying quaternion and vector methods to problems in mechanics and in geometry, development of theories of conjugate algebraic couple functions, solvability of polynomial equations and general quintic polynomial solvable by radicals, the analysis on Fluctuating Functions, linear operators on quaternions and proving a result for linear operators on the space of quaternions, which is a special case of the general theorem which today is known as the Cayley–Hamilton theorem. He also invents Icosian calculus, which he uses to investigate closed edge paths on a dodecahedron that visit each vertex exactly once.

Hamilton retains his faculties unimpaired to the very last, and steadily continues the task of finishing the Elements of Quaternions which occupies the last six years of his life. He dies on September 2, 1865, following a severe attack of gout precipitated by excessive drinking and overeating. He is buried in Mount Jerome Cemetery in Dublin.


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Death of Inventor Alexander Mitchell

alexander-mitchellAlexander Mitchell, Irish engineer who from 1802 is blind, dies on June 25, 1868. He is known as the inventor of the screw-pile lighthouse.

Mitchell is born in Dublin on April 13, 1780. His family moves to Belfast while he is a child. He receives his formal education at Belfast Academy where he excels in mathematics. He begins to notice that his eyesight is failing. By the age of 16 he can no longer read and by the age of 22 he is completely blind.

Undeterred, Mitchell borrows £100 and starts up a successful business making bricks in the Ballymacarrett area of Belfast. This enables him to start building his own houses and he completes approximately twenty in the city. It is during this period that his talent for inventing comes to the fore and he fabricates several machines for use in brick-making and the building trade.

Mitchell patents the screw-pile in 1833, for which he later gains some fame. The screw-pile is used for the erection of lighthouses and other structures on mudbanks and shifting sands, including bridges and piers. His designs and methods are employed all over the world from the Portland, Maine breakwater to bridges in Bombay. Initially it is used for the construction of lighthouses on Maplin Sands in the Thames Estuary in 1838, at Fleetwood Lancashire (UK) Morecambe Bay in 1839 and at Belfast Lough where his lighthouse is finished in July 1844.

In 1848 Mitchell is elected member of the Institution of Civil Engineers (ICE) and receives the Telford Medal the following year for a paper on his invention.

In May 1851 Mitchell moves to Cobh to lay the foundation for the Spit Bank Lighthouse. The success of these undertakings leads to the use of his invention on the breakwater at Portland, the viaduct and bridges on the Bombay, Baroda and Central India Railway and a broad system of Indian telegraphs.

Mitchell becomes friendly with astronomer John Thomas Romney Robinson and mathematician George Boole.

Alexander Mitchell dies at Glen Devis near Belfast on June 25, 1868 and is buried in the old Clifton graveyard in Belfast. His wife and daughter predecease him.