AZALEA

(Yunanca köken — orijinale bakınız.) A genus of beautiful plants inhabiting North America and China. They have trumpet-shaped or bell-shaped richly coloured flowers, which are in some species fragrant. The name has apparently been derived from the dry brittle nature of their branches. They differ from rhododendron chiefly in being deciduous. AZIMUTH.: (From the Arabic.) A term used in astronomy, to denote the arc of the horizon intercepted between the meridian and the vertical circle pa ing thro i^h a star or otlier celestial body; or the angle made at the zenith by the meridian and the vertical circle in which the body is situated. The azimuth may be counted either from the north or the south point of the horizon: modern astroiMmers seem to prefer beginning at the north point, and counting eastward and westward to 180O; but it is not one of those elements usually observed in astronomy, being easily deduced from the declination, which can be measured much more conveniently and accurately. In trigonometrical surveys, however, on the earth's surface, the accurate determination of the azimuth of an object is an operation of very great importance. It is usually made with the theodolite. AZIMUTH CIRCLES, or VERTICAL CIRCLES, are great circles of the sphere pa ing through the zenith, and intersecting the horizon at right angles. [s. 126]