years. He is recognized as an avithority in the delineation of animals, particularly those ■which are domestic or semi-domestic.
WEIR, John Feeguscn (1841—). An
American artist, the son of Robert Walter Weir
(q.v.), born at West Point, N. Y. He received
his early training from his father, and in 1861
opened a studio in New York City. In 1864 he
was elected an associate of the Xational Academy
of Design and two years afterwards an acade-
mician. Ill IS6S-69 he was abroad and upon his
return became director of the School of Fine
Arts at Yale University. Among his best-known
paintings are "Forging the Shaft." "Tapping the
Furnace," "Returning from Work," "Venice,"
and portraits of Admiral Farragut, President
Dwight of Yale, and Wells Williams. In sculp-
ture his statues of President Woolsey and the
elder Professor Silliman are well known. He
wrote The ir.-i?/, the Xatiire, and the ileans of
Revelation (1880); ./o7ij!. Trumhull and Eis
Works (1902) ; and Eiiman Destiny in the Light
of Revelation (1903).
WEIR, .JuLi.^N Aldex (18.52 — ). An Ameri-
can portrait, genre, and landscape painter. He
was born at West Point, August 30, 1852, and
received his first instruction from his father,
Robert Walter Weir (q.v.). He studied at Paris
under G^-rome in 1873-76, and during his first
student days was closely associated with Bas-
tien-Lepage, who much influenced his art. After
his return to America he was one of the found-
ers of the Society of American Artists (1877),
and at one time its president, but seceded as
one of the 'Ten American Artists' in 1898. He
became National Academician in 1886. He re-
ceived the .$2000 prize of the American Art As-
sociation in 1886 with the "Idle Hours" (Metro-
politan Museum, Xew York City), and a second-
class medal at the Paris E.xposition in 1889 with
a "Breton Interior." His works are always ar-
tistic and highly personal; the earlier ones are
sombre in tone, but after 1887 he followed im-
pressionistic methods, achieving his results in the
treatment of light and air in landscape. He shows
liimself cciually at home in genre and portrait.
WEIR, Robert Walter (1803-89). An
American historical and genre painter, born in
New Rochelle, N. Y. He studied under Jarvis
in New York City, and from 1824 to 1828 under
Benvenuti at Florence. He was elected to the
National Academy in 1829. and somewhat later
was ajipointed professor of drawing at the United
States Military Academy at West Point, hold-
ing the position for forty-two years. A'eir was
among the first of American painters to devote
liimself to historical subjects, in which branch
of art he is best known. Among his paintings
are the "Embarkment of the Pilgrims" (1845),
in the rotunda of the Capitol at Washington : the
"Landing of Hcndrik Hudson" (1842); the
"Church of the Holy Innocents" (1847, Cor-
coran Oalleiy, Washington) ; and "Cohinilius Be-
fore the Council of Salamanca" (1884). His
finest production is probably the large allegorical
work, "Peace and War," executed for the chapel
at West Point. He also designed the stained
glass windows of Trinity Chapel and Calvary
Church, New York City. Some good portraits by
liim arc :it (lie West Point Academy.
WEISBACH, vls'biic, .Ivi.ir.s (1806-71). A
German mathematician and mining engineer.
born near Annaberg. He studied at Freiburg,
Giittingen, and Vienna, and became profes.sor in
the school of mines at Freiburg (1833). He is
principally known for his work in hydraulics and
mechanics, his introduction and development of
the surveying of mines, and the extension of
axonometry. He wrote: Bandbuch der Berg-
masehinenmechanilx' (1836) : Experimentalhy-
draulik (1855); Lehrhuch der Ingenienr- und
Maschinenmeehanik (1845-60. and subsequent edi-
tions) : Der Ingenieur ( 1848 ; 7th ed. by Reuleaux,
1896): Die n'eiie Markseheidekunst ' (lS5-50) ;
Anlcitung sum axonometrischen Zeiclmen (1857).
WEISHATTPT, vTs'houpt, Adam (1748-1830).
A German mystic and religious leader. He
was born at Ingolstadt, studied law in his
native citj-, and after 1772 was professor of
canon law in the university there. In 1776 he
declared himself an open enemy of the Jesuits,
whose pu])il he had been, and on May 1st of that
year founded the Order of the Illuminati, or, as it
was at first called, Gesellsehaft der Perfectabil-
isten, the members of which were entirely sub-
servient to their superiors, though theoretically
vowed to the propagation of liberty. Weishaupt
attracted great numbers of young men. espe-
cially those of good family, by his teaching, and
made Ingolstadt a cosmopolitan centre till 1785,
when his lecture hall was burned by his enemies.
He then removed to Gotha. where he died. Among
his writings were the following: Apologie der
Illuminaten (1786); Gesehiehfe der Verfolgung
der Illurninaten (1786) ; and Dns verbesserte Sys-
tem der Ilhi mi naten (1787). See Illuminati.
WEISMANN, vis'man. ArousT (1834-). A distinguished German zoologist. He was born
January 17, 1834, at Frankfort-on-the-Main,
studied medicine at Gottingen, was clinical as-
sistant at Rostock in 1856-57, went to Vienna in
1858, to Italy in 1859, and in 1860 to Paris.
In 1863 he studied zoiilogy as a pu]iil of Leuck-
art at Ciiessen, began to lecture at the University
of Freiburg in Baden in the same ,vear, and be-
came in 1866 extraordinary, and in 1871 full pro-
fessor of zoology. Weismann"s epoch-making work
on the embryology of the flies appeared in 1864.
He first revealed the real nature of the internal
changes wrought during the process of meta-
morphosis of insects. His discovery of the germs
of the perfect insect (imaginal buds) in the
larva, and his theory of 'histolysis," or of the
complete destruction of the larval organs by a
gradual process, led to the final and complete
overthrow of the earlier theory of incasement
{cinboitement) or preformation (q.v.). These
investigations were succeeded by his studies on
the formation of the egg and the embryology of
the little crustaceans Daphnidse (1876-79), and
the origin of the sexual cells of the Hydromedusre
(1883). Another and most fruitful line of in-
vestigation were his researches on the seasonal
dimorphism of butterflies, and the origin of the
markings of catcrjiillars, as embodied in his
Studies on the Theory of Descent (1875). As
the result of impaired eyesight Weismann was
obliged to abandon microscopic work, and devoted
himself to jihilosophical and speculative studies
connected with the theory of descent and the
problems of heredity. From being a moderate
l.amarckian and selectionist he went to the ex-
treme of asserting the "all-suniciency of natural