Magnetic field

A magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude (or strength); as such it is a vector field. The term is used for two distinct but closely related fields denoted by the symbols B and H, where H is measured in units of amperes per meter (symbol: A·m⁻¹ or A/m) in the SI. B is measured in teslas (symbol:T) and newtons per meter per ampere (symbol: N·m⁻¹·A⁻¹ or N/(m·A)) in the SI. B is most commonly defined in terms of the Lorentz force it exerts on moving electric charges.

Magnetic fields can be produced by moving electric charges and the intrinsic magnetic moments of elementary particles associated with a fundamental quantum property, their spin. In special relativity, electric and magnetic fields are two interrelated aspects of a single object, called the electromagnetic tensor; the split of this tensor into electric and magnetic fields depends on the relative velocity of the observer and charge. In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.

Barron Field (author)

Barron Field (23 October 1786 – 11 April 1846) was an English-born Australian judge and poet.

Early life

Field was the second son of Henry Field, a London surgeon and apothecary, and Esther, née Barron. Barron Field was educated as a barrister and was called to the Inner Temple on 25 June 1814. He was a great student of poetry and frequently contributed to the press, being for a time theatrical critic for The Times. He became acquainted with Charles Lamb and his circle; Crabb Robinson called on Field in January 1812 and found Lamb and Leigh Hunt there, and he records in another place that at Lamb's house on 23 May 1815 he met William Wordsworth, Field, and Thomas Noon Talfourd.

Judge in New South Wales

In 1816 Field accepted a commission as judge of the Supreme Court of New South Wales, and arrived in Sydney on 24 February 1817. Governor Macquarie, writing to Under-secretary Goulburn in April thanked him "for making me acquainted with Mr Field's character. He appears to be everything that you say of him and I am very much prejudiced in his favour already from his mild modest and conciliating manners, and I am persuaded he will prove a great acquisition and blessing to this colony". Field was soon at work framing the necessary "Rules of Practice and Regulations for conducting the Proceedings of the Court". His salary was £800 a year with a residence, government servants, and rations for himself.