Base. (1) (Fr. bas, Late Lat. bassus, low; cf. Gr. βαθύς) an adjective meaning low or deep, and so mean, worthless, or wicked. This sense of the word has sometimes affected the next, which is really distinct. (2) (Gr. βάσις, strictly "stepping," and so a foundation or pedestal) a term for a foundation or starting point, used in various senses; in sports, e.g. hockey and baseball; in geometry, the line or face on which a figure or solid stands; in crystallography, e.g. "basal plane"; in surveying, in the "base line," an accurately measured distance between the points from which the survey is conducted; in heraldry, in the phrase "in base," applied to any figure or emblem placed in the lowest part of a shield.
In chemistry the term denotes a substance which combines with an acid to form a salt. In inorganic chemistry such compounds are almost invariably oxides or hydroxides, and water in eliminated during the combination; but in organic chemistry many compounds exist, especially ammonia derivatives, which directly combine with acids. Chemical bases are consequently antithetical to acids; and an acid is neutralized by a base with the production of a salt. They reverse certain colour reactions of acids, e.g. turn red litmus blue; this is termed an "alkaline reaction."
In architecture the "base" is the lowest member of a column or shaft. In Egyptian and Greek architecture it is the raised slab in stone or cement on which the primitive timber column was placed, to keep it dry. Afterwards it was always reproduced in Egypt, even although the column, being in stone, no longer required it; a custom probably retained because, being of a much larger circumference than the lower part of the column, it gave increased stability. In Assyrian architecture, where it served to carry wooden posts or columns, it took the form of a large torus moulding with enrichments. In Persian architecture the base was much higher than in any other style, and was elaborately carved. In primitive Greek work the base consisted of the stone plinth as found in Crete and Tiryns, and of three small steps at Mycenae. In archaic Greek work it has already disappeared in the Doric order, but in the Ionic and Corinthian orders it is more or less richly moulded, the most elaborate examples being those found in the temple of Apollo at Branchidae in Milesia. For the contour of the mouldings see Orders. The Roman orders all have the favourite design known as the Attic base.
Romanesque bases were rude but vigorous copies of the old classic base, and were often decorated with projections or spurs (Fr. griffes) at the angles of the square dies, thus connecting them with the square base. In the Early English style, these spurs followed the conventional design of the period, and about the same time the mouldings were deeply sunk and occasionally cut downwards, so that they would have held water if used externally. Later, the base becomes less bold in treatment, but much more complex in its contours, and in the 15th century is given an unusual height with two stages, the lower one constituting a kind of plinth, which is sometimes known as the ground table, or the base course.
A Base Court (Fr. basse cour, i.e. the lower court), is the first open space within the gates of a castle. It was used for exercising cavalry, and keeping live stock during a siege. (See Enceinte).
The Base of a Wall or Ground Table, in architecture, is the mouldings round a building just above ground; they mostly consist of similar members to those above described and run round the buttresses. The flat band between the plinth and upper mouldings is frequently panelled and carved with shields, as in Henry VII. Chapel at Westminster.