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, Joseph Hopkinson (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
