solidifying ultimately build up mountains which have comparatively gentle slopes. Thus the Hawaiian Islands, which are built up of basalt from the sea-bottom, have, in contrast with the slopes of the American Cordilleran volcanoes, which are generally rhyolite or andesite, ex- ceedingly gentle slopes. Masses of basalt, when solidified at the surface, have, quite generally near the original upper surfaces, a separation by cracks into layers parallel to the surface; where- as at greater depths there is produced a series of columns, generally hexagonal in section, and with their columnar axes perpendicular to the original surface. The upper surfaces of a basalt outflow being curved, the columns generally radi- ate from some point near the bottom of the mass. As the upper layers of rock have been re- moved by erosion in all save the most recent extrusions of lava, the platy parting is less commonly observed than is the columnar. The Giant's Causeway, in the north of Ireland, is the best-known example of columnar joints in ba- salt. In common with most other lavas, basalt exhibits all varieties of cellular and scoriaceous texture, depending upon the quantity of steam the lava had absorbed and upon the opportuni- ties afforded this steam to expand when it reached the surface. (For illustration, see Giant's Causeway.) Very similar rocks to basalt are diabase, melaphyre, and augite porphyritc.
BASAN, ba'zilN',
Pierre François (1723-98). A French engraver and writer on art. He was born in Paris, and studied with Jean Daullé and with his uncle, Etienne Fessard. The most noteworthy of his engravings are: "Jupiter and Antiope," after Allegri (Louvre); "Ecce Homo," after Caravaggio; and "Burgomaster Six," after Rembrandt. He later became established in Paris as a publisher of engravings. About 1250 plates, in 12 volumes, were executed by him or under his direction. His most important literary work is the Dictionnaire des graveurs anciens et modernes (1809).
BASANITE, baz'a-nit.
See Touchstone.
BAS'COM, Florence. An American geologist, daughter of Dr. John Bascom. She was born in Williamstown, Mass. In 1882 she graduated with the degrees of A.B. and B.L. at the University of Wisconsin, from which institution she also received the degree of B.S. in 1884. She continued her studies at the University of Wisconsin, taking her master's degree there, and at Johns Hopkins University, where she received the degree of Ph.D. She became a member of the American Academy for the Advancement of Science and of the Philadelphia Academy of Science, and has been assistant editor of the American Geologist.
BASCOM, John (1827—). A distinguished American educator; born at Genoa, N. Y. He graduated at Williams College in 1849, was a tutor there from 1852-53, and graduated at the Andover Theological Seminary in 1855. He was professor of rhetoric at Williams from 1855 to 1874, when he was chosen president of the University of Wisconsin. At Wisconsin, in addition to the presidency, he also held the chair of mental and moral philosophy. He withdrew from the university in 1887 and returned to Williams to accept the chair of political science, which he held until he retired in 1901. Dr. Bascom has been prominent as a speaker and a writer on both religious and secular subjects; but it is for his efficient service as a teacher, and his publications, that he is best known. His works include a textbook of Political Economy (1859); Æsthetics (1862); The Principles of Psychology (1869); The Philosophy of English Literature (1874); Ethics (1879); Problems in Philosophy (1885); The Growth of Nationality in the United States (1899); and God and His Goodness (1901).
BASCULE BRIDGE. See Bridge.
BASE, bas (Fr. and It., from Lat. basis, Gk.
^dcns, basis, a stepping, step). In architecture,
the foot or lowest part or division of any archi-
tectural construction, such as a wall, pier, or col-
umn. We speak of base-molding, base-course,
base-block, to designate different parts of a base.
Its most popular and definite use is to designate
the third and lowest member of a column or
pier, the other two being the capital and the
shaft. (See Column.) When Egyptian columns
had a base, it was merely an unmolded block;
the Assyrians went further, and invented a base
with torus and scotia moldings. The Mycenaean
columns had bases; but of the two great styles
that divided the Hellenic world in the historic
age, the Doric had no base, while the Ionic de-
veloped a very clear type, which was at first
extremely rich in Asia Minor (Seventh and Sixth
centuries), and became simplified and of a uni-
form type in the Attic School of the Fifth Cen-
tury B.C. The Persians used a modified form of
the early Ionic base of Asia Minor at Persepolis
and Susa, and this mixed form influenced Hel-
lenic, and even Roman, work in the Orient. The
Corinthian and Composite orders, and the Roman
Doric, used the simple Attic Ionic base, with
modifications. This consisted of (1) a fillet;
(2) an upper convex molding (torus); (3) a
scotia or concave molding between two fillets;
(4) a larger convex molding; (5) a plinth or
base-block; its total height was normally about
half the diameter of the column. The Ionic base
continued in early Christian, Byzantine, and
Mediaeval art, not in the stereotyped form given it
by the Romans, but with increasing freedom and
richness in treatment and decoration. While
Ital.y retained this tradition throughout the
Gothic period, and re-popularized it with the
spread of its Renaissance style over Europe,
there had been an interval when the Romanesque
and Gothic styles of the rest of Europe had de-
veloped an unparalleled variety and richness in
the designs of Ionic bases, usually with more
flare; every combination of moldings and of fo-
liated ornament was tried, especially in France.
The grouped piers of the Gothic style gave great
scope to original treatment. See Architecture.
BASE. In chemistry, a radical which is capa-
ble of replacing entirely or in part the hydrogen
of an acid, neutralizing its acid properties, and
forming a salt. A base may be a metallic oxide,
as the oxide of potassium, K.O; a metallic hy-
droxide, as the hydroxide of potassium, KOH;
ammonia, NH„ or some allied compound. Ac-
cording as one reacting weight of a base acts
with one, two, or more reacting weights of a
monobasic acid to form a salt, the base is said
to be mono-acid, di-acid, tri-acid, etc. The so-called organic bases, i.e. basic compounds containing carbon as one of their constituent elements, are grouped chiefly into two classes, viz.
