| 释义 |
azimuth|ˈæzɪməθ|
Forms: 4–5 azimut, azymut, 4–7 azymuth, 6 azumuth, (7 azimynth, -moth), 6– azimuth.
[a. F. azimut, cogn. with It. azzimutto, Pg. azimuth, ad. Arab. as-sumūt, i.e. as = al the + sumūt, pl of samt way, direction, a direction or point of the compass or horizon, and the arc extending from it to the zenith. Cf. samt-al-rā's the direction or point over head, whence the term zenith. With the form azimynth cf. It. aziminthi (Florio).]
1. An arc of the heavens extending from the zenith to the horizon which it cuts at right angles; the quadrant of a great circle of the sphere passing through the zenith and nadir, called an azimuth-circle.
c1391Chaucer Astrol. i. §19 From this senyth..ther come a maner krokede strikes like to the clawes of a coppe..kervyng ouerthwart the almikanteras. And thise same strikes or diuisiouns ben cleped azymuthz. Thise Azimutz seruen to knowe the costes of the firmament. 1594J. Davis Seamans Secr. ii. (1607) 8 Circles of Azumuths, or verticall circles, are quarters of great circles, concurring together in the Zenith. 1598Sylvester Du Bartas (1608) 299 The almycantharats, With th' azimynths. 1651Biggs New Disp. ⁋157 Severall azimuths meeting in the Zenith. 1796Hutton Math. Dict. I. 178/2 These azimuths are represented..on the globe by the quadrant of altitude. 1874Moseley Astron. ix. 45 If a great circle..be imagined to be drawn from the zenith..to the horizon, through any star..it is called the azimuth circle of that star.
2. The angular distance of any such circle from a given limit, e.g. a meridian. Hence, the true azimuth of a heavenly body is, the arc of the horizon intercepted between the north (or, in the Southern hemisphere, south) point of the horizon and the point where the great circle passing through the observed heavenly body cuts the horizon. Its magnetic azimuth is the arc intercepted between the magnetic meridian and this great circle.
azimuth compass: a minutely divided mariner's compass, fitted with vertical sights, used for taking the magnetic azimuth of a heavenly body. azimuth dial: one whose gnomon is perpendicular to the plane of the horizon. azimuth mirror: an instrument placed on the glass cover of a mariner's compass and used for taking azimuths.
1626Capt. Smith Accid. Yng. Seamen 36 Learne to obserue..the Sunnes Azimuth and Almicanter. 1697W. Dampier Voy. (1729) I. 531 The Azimuth Compass, an Instrument more peculiar to the Seamen of our Nation. 1762–9Falconer Shipwr. i. 740 The pilots now their azimuth attend. 1834Nat. Philos. III. Astron. xiii. 255/1 (U.K.S.) The true azimuth, compared with the magnetic azimuth, will give the deviation of the compass.
b. in azimuth: in a horizontal circular direction.
1831Brewster Optics xiv. 123 If we turn the steel plate round in azimuth. 1879G. B. Prescott Sp. Telephone 269 The mirror is so mounted as to swing in azimuth.
3. transf. and fig. Horizontal angle, or direction; point of the compass.
1667Sir R. Moray in Phil. Trans. II. 477 Note also, at what Azimuth the Mark stands from the Gun. 1831Brewster Optics xix. 167 Reflected from the second plate, at the azimuths 90° and 270°. 1860Maury Phys. Geog. Sea iv. §245 Wind gauges..to show the inclination, as well as the Azimuth of the wind. 1867Carlyle Remin. II. 52 How he found his way thither I know not (perhaps in a cab, if quite lost in his azimuth). |