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 from which he received his bachelor’s degree in 1757 and his master’s degree in 1760. He then studied law in the office in Philadelphia of Benjamin Chew, and was admitted to the bar in 1761. Removing after 1768 to Bordentown, New Jersey, he became a member of the council of that colony in 1774. On the approach of the War of Independence he identified himself with the patriot or whig element in the colony, and in 1776 and 1777 he was a delegate to the Continental Congress. He served on the committee appointed to frame the Articles of Confederation, executed, with John Nixon (1733–1808) and John Wharton, the “business of the navy” under the direction of the marine committee, and acted for a time as treasurer of the Continental loan office. From 1779 to 1789 he was judge of the court of admiralty in Pennsylvania, and from 1790 until his death was United States district judge for that state. He was famous for his versatility, and besides being a distinguished lawyer, jurist and political leader, was “a mathematician, a chemist, a physicist, a mechanician, an inventor, a musician and a composer of music, a man of literary knowledge and practice, a writer of airy and dainty songs, a clever artist with pencil and brush and a humorist of unmistakeable power” (Tyler, Literary History of the American Revolution). It is as a writer, however, that he will be remembered. He ranks as one of the three leading satirists on the patriot side during the War of Independence. His ballad, The Battle of the Kegs (1778), was long exceedingly popular. To alarm the British force at Philadelphia the Americans floated kegs charged with gunpowder down the Delaware river towards that city, and the British, alarmed for the safety of their shipping, fired with cannon and small arms at everything they saw floating in the river. Hopkinson’s ballad is an imaginative expansion of the actual facts. To the cause of the revolution this ballad, says Professor Tyler, “was perhaps worth as much just then as the winning of a considerable battle.” Hopkinson’s principal writings are The Pretty Story (1774), A Prophecy (1776) and The Political Catechism (1777). Among his songs may be mentioned The Treaty and The New Roof, a Song for Federal Mechanics; and the best known of his satirical pieces are Typographical Method of conducting a Quarrel, Essay on White Washing and Modern Learning. His Miscellaneous Essays and Occasional Writings were published at Philadelphia in 3 vols., 1792.

His son, (1770–1842), graduated at the University of Pennsylvania in 1786, studied law, and was a Federalist member of the national House of Representatives in 1815–1819, Federal judge of the Eastern District of Pennsylvania from 1828 until his death, and a member of the state constitutional convention of 1837. He is better known, however, as the author of the patriotic anthem “Hail Columbia” (1798).

HOPKINSON, JOHN (1849–1898), English engineer and physicist, was born in Manchester on the 27th of July 1849. Before he was sixteen he attended lectures at Owens College, and at eighteen he gained a mathematical scholarship at Trinity College, Cambridge, where he graduated in 1871 as senior wrangler and first Smith’s prizeman, having previously taken the degree of D.Sc. at London University and won a Whitworth scholarship. Although elected a fellow and tutor of his college, he stayed up at Cambridge only for a very short time, preferring to learn practical engineering as a pupil in the works in which his father was a partner. But there his stay was equally short, for in 1872 he undertook the duties of engineering manager in the glass manufactories of Messrs Chance Brothers and Company at Birmingham. Six years later he removed to London, and while continuing to act as scientific adviser to Messrs Chance, established a most successful practice as a consulting engineer. His work was mainly, though not exclusively, electrical, and his services were in great demand as an expert witness in patent cases. In 1890 he was appointed director of the Siemens laboratory at King’s College, London, with the title of professor of electrical engineering. His death occurred prematurely on the 27th of August 1898, when he was killed, together with one son and two daughters, by an accident the nature of which was never precisely ascertained, while climbing the Petite Dent de Veisivi, above Evolena. Dr Hopkinson presented a rare combination of practical with theoretical ability, and his achievements in pure scientific research are not less intrinsically notable than the skill with which he applied their results to the solution of concrete engineering problems. His original work is contained in more than sixty papers, all written with a complete mastery both of style and of subject-matter. His name is best known in connexion with electricity and magnetism. On the one hand he worked out the general theory of the magnetic circuit in the dynamo (in conjunction with his brother Edward), and the theory of alternating currents, and conducted a long series of observations on the phenomena attending magnetization in iron, nickel and the curious alloys of the two which can exist both in a magnetic and non-magnetic state at the same temperature. On the other hand, by the application of the principles he thus elucidated he furthered to an immense extent the employment of electricity for the purposes of daily life. As regards the generation of electric energy, by pointing out defects of design in the dynamo as it existed about 1878, and showing how important improvements were to be effected in its construction, he was largely instrumental in converting it from a clumsy and wasteful appliance into one of the most efficient known to the engineer. Again, as regards the distribution of the current, he took a leading part in the development of the three-wire system and the closed-circuit transformer, while electric traction had to thank him for the series-parallel method of working motors. During his residence in Birmingham, Messrs Chance being makers of glass for use in lighthouse lamps, his attention was naturally turned to problems of lighthouse illumination, and he was able to devise improvements in both the catoptric and dioptric methods for concentrating and directing the beam. He was a strong advocate of the group-flashing system as a means of differentiating lights, and invented an arrangement for carrying it into effect optically, his plan being first adopted for the catoptric light of the Royal Sovereign lightship, in the English Channel off Beachy Head. Moreover, his association with glass manufacture led him to study the refractive indices of different kinds of glass; he further undertook abstruse researches on electrostatic capacity, the phenomena of the residual charge, and other problems arising out of Clerk Maxwell’s electro-magnetic theory.

His original papers were collected and published, with a memoir by his son, in 1901.

HOPKINSVILLE, a city and the county-seat of Christian county, Kentucky, U.S.A., about 150 m. S.W. of Louisville. Pop. (1890) 5833; (1900) 7280 (3243 negroes); (1910) 9419. The city is served by the Illinois Central and the Louisville & Nashville railways. It is the seat of Bethel Female College (Baptist, founded 1854), of South Kentucky College (Christian; co-educational; chartered 1849) and of the Western Kentucky Asylum for the Insane. The city’s chief interest is in the tobacco industry; it has also considerable trade in other agricultural products and in coal; and its manufactures include carriages and wagons, bricks, lime, flour and dressed lumber. When Christian county was formed from Logan county in 1797, Hopkinsville, formerly called Elizabethtown, became the county-seat, and was renamed in honour of Samuel Hopkins (c. 1750–1819), an officer of the Continental Army in the War of Independence, a pioneer settler in Kentucky, and a representative in Congress from Kentucky in 1813–1815. In 1798 Hopkinsville was incorporated.

HOPPNER, JOHN (1758–1810), English portrait-painter, was born, it is said, on the 4th of April 1758 at Whitechapel. His father was of German extraction, and his mother was one of the German attendants at the royal palace. Hoppner was consequently brought early under the notice and received the patronage of George III., whose regard for him gave rise to unfounded scandal. As a boy he was a chorister at the royal chapel, but showing strong inclination for art, he in 1775 entered as a student at the Royal Academy. In 1778 he took a silver medal for drawing from the life, and in 1782 the Academy’s highest award, the gold medal for historical painting, his subject