AUSTRAL, Southern. (L., Auster, the| south wind.) The TROPICS are two smaller circles situated on the opposite sides of The NORTH is the region of the the equator, and at the distance of earth and sky which is opposite to 23° 28' from that circle. the south. BOREAL, northern. (L., Boreas, the north wind.) SEPTENTRIONAL, northern. (L., Septentrio, a northern constellation, called Charles's Wain.) ARCTIC, northern. (Gr., Afxtos [Arctos], the northern constellation of the Bear.) Antarctic, southern. (Opposite to the arctic. Gr., avT [anti], opposite.) The ZENITH is the point in the heavens directly over the head of the spectator. The NADIR is the point in the heavens which is directly opposite to the zenith. The nadir is directly under the place where we stand. The EQUATOR is a line drawn east and west around the earth at an equal distance from each pole. NOTE.-The equator is thus called because when the sun is in the plane of this circle the days and nights are equal all over the world. A MERIDIAN is a great circle of the sphere passing through the earth's axis, and the zenith of the spectator. NOTE.-Meridians are represented on artificial globes by lines drawn north and south, and meeting at the poles. These are also called noon lines. (L., meridies, noon.) LATITUDE is distance from the equator either north or south. (L., latus, broad, because the breadth of the habitable world, as known to the ancients, extended from north to south. NOTE. The tropics mark the limits of the sun's northern and southern declination. (Gr., Tрon [trope], a return, because when the sun has touched either tropic, he immediately begins to return to the opposite tropic.) The Tropic of Cancer is the northern tropic, thus called because the sun touches this circle when he is about entering the constellation of Cancer. (See Art. Astronomy.) The Tropic of Capricorn is the southern tropic, thus called because the sun touches this circle when he is about entering the constellation of Capricorn.) THE ARCTIC CIRCLE is drawn within 23° and 28' of the north pole, and marks the limits of constant day during the twenty-four hours when the sun is at the northern tropic. The ANTARCTIC CIRCLE is drawn at the distance of 23° 28′ from the south pole, for a reason similar to that assigned above. The ZONES are five belts on the earth's surface, bounded by the tropics and the polar circles. (Gr., wvn [zo'ne], a girdle.) CLIMATE, among the ancient geographers, was applied to denote that obliquity of the sphere with respect to the horizon, which gives rise to the inequality of day and night. They divided the space comprehended between the equator and the pole, into thirty equal parts, which they denominated climates, or inclinations. (Gr., xxwa [clino], to incline).-Brande. LONGITUDE is distance east or west, from any established meridian. (L., longus, long, because the length of the habitable world, as known to Climate, in the ordinary acceptathe ancients, extended east and west.) tion of the term, embraces all those A DEGREE is one three-hundred- modifications of the atmosphere, by and-sixtieth part of the earth's cir- which our organs are sensibly afcumference, or about 69 miles. |fected.-Brande. A MINUTE is one sixtieth part of a degree. A SECOND is one sixtieth part of a minute. 13 To Acclimate is to habituate the body to a new climate. (ad, to.) Clime is a poetical form of the word climate. OF I. General Terms. ASTRONOMY. is to kill the part in which the evapo- 'HAIOX [HELIOS], the sun. (Gr.) Hence, Heliocentric. The heliocentric ASTRONOMY is the science which treats of the motions, magnitudes, and distances of the heavenly bodies. (Gr., 277gov [astron], a heavenly body; and roues [nomos], a law.) HEAVEN is, 1. The dome-like arch place of a heavenly body is its posi which seems to be heaved up over our tion as seen from the sun. heads. 2. The regions of space which Helioscope, an instrument for viewThe abode of the blest, from the idea ing the sun without injury to the eye. of its being situated somewhere within (Gr., oxoTew [scopeo], to view.) the limits of the physical heavens. The SKY includes the regions of the air, and extends indefinitely upward The WELKIN is the vault of heaven, surround the earth on all sides. 3. or the visible regions of the air. (A poetical word.) "Their hideous yells rend the dark welkin. Philips. The FIRMAMENT includes the region of the fixed stars. (L., firmamentum, the firm, or solid sphere, in which, according to the ancient astronomers, the fixed stars were set.) CœLUM, heaven. (L.) ́Hence, heavens. ets. Uranus, one of the primary plan Urania, the Muse of astronomy. The HEAVENLY BODIES include the sun, the moon, and the stars. 2. Of the Sun. The SUN is the source of light and heat to our world. NOTE. The diameter of the sun is 892,000 miles. Its bulk is 1,400,000 times greater than that of the earth, and its distance from the earth is 96,000,000 miles. SOL, the sun. (L.) Hence, Solar, pertaining to the sun; as, solar light. Insolation, a local disease of plants attributable to exposure to too bright Perihelion, the point in the orbit of a planet, or comet, which is nearest to the sun. (TEP [peri], near to.) Aphelion, the point in the orbit of from the sun. (ano [apo], remote from.) a planet, or comet, which is farthest Parhelion, a mock-sun. See Art., Light. 3. Of the Stars. stars. Asterism, a small cluster of stars. Asterisk, the figure of a star, thus, *, used in printing or writing, as a reference to a note in the margin, or to fill the space when a name, or part of a name, is omitted. NOTE 1.-There are three general classes of stars; planets, comets, and fixed stars. NOTE 2.-The planets and comets, in connec tion with the sun, constitute the Solar System. 4. Of the Planets. A PLANET is a solid body revolv a light, which causes an excessively ing around the sun, in an orbit of a rapid evaporation, the effect of which moderate degree of eccentricity. NOTE.-The planets are thus called because NOTE.-There are two equinoxes; the vernal they wander, or change their position, among and the autumnal. the fixed stars. (Gr., λvn [plane], a wandering.) The ORBIT of a planet, or other heavenly body, is the path in which it moves around a center of attraction. (L., orbis, a circle.) NOTE 1.-The orbits of all the heavenly bodies, so far as is known, are ellipses, in one of whose foci is situated the body around which the moving body revolves. NOTE 2.-An ELLIPSE is a curvilinear figure, as A CBD, having two fixed points, E and F. called foci, the sum of whose distances, EH+ K D L B FH, EK+FK, EL+F L, etc., from any point in the periphery, is always the same. NOTE 3.-Focus is a Latin word signifying a fire-place. The term was first applied in a metaphorical sense, to the point in which the sun's rays are concentrated by a burning glass, in allusion to the heat; and afterward to certain points in which geometrical lines meet. (pl. foci.) The ECCENTRICITY of an orbit is the distance of either focus from the center of the orbit. (Gr., ex [ec], from, and xvrgov [centron], the center.) NOTE. The eccentricity of the earth's orbit is about one and a half millions of miles. When, therefore, the earth is in its perihelion, it must be three millions of miles nearer to the sun than when in its aphelion. The ECLIPTIC is the path or way among the fixed stars, which the earth, in its orbit, appears to describe to an eye placed in the sun. NOTE 1.-The ecliptic is thus called from the word eclipse, because eclipses of the sun or moon can happen only when the moon is in or near the plane of the earth's orbit. NOTE 2.-The plane of the ecliptic forms an angle of twenty-three degrees twenty-eight minutes with the plane of the equator. The EQUINOXES are the points of time at which the sun passes the equator. (L., æquus equal, and nox, night; because, when the sun is at the equator, the days and nights are equal in length all over the world.) The Vernal Equinox occurs on the 21st of March. The Autumnal Equinox occurs on the 22d of September. The SOLSTICES are the points of time at which the sun is at the greatest distance from the equator. (L., sol, the sun, and sto, to stand; because when the sun has attained, his greatest northern or southern declination, he seems to stand for a short time before he begins to return.) NOTE.-There are two solstices; the summer and the winter solstice. The Summer Solstice occurs on the 21st day of June. The Winter Solstice occurs on the 21st day of December. their orbits between those of Mars The APOGEE is the point of the and Jupiter, and at an average dis- Moon's orbit which is farthest from tance of about 260 millions of miles the earth. (Gr., ano [apo], from; and 2 [ge], the earth.) from the sun. The following is a list of these bodies: IN THE YEAR 1801 1807 1845 1847 1847 1848 The NODES are the points where the orbit of the Moon intersects or pierces the plane of the Earth's orbit. (L., nodus, a knot.) The Ascending Node is the point at which the Moon penetrates the plane of the ecliptic in passing from south to north. The Descending Node is the point 1849 at which the Moon passes the plane of the ecliptic in moving from north to south. The PHASES OF THE MOON, are the various appearances which she assumes. (Gr., paois [phasis], an ap1853 pearance.) 1852 1850 Victoria Hind 1850 1850 Irene Hind 1851 1851 1852 1852 1853 Goldschmidt Goldschmidt 1853 1852 The CHANGE OF THE MOON takes 1852 place at the moment when she 1852 passes the sun, and commences a new monthly revolution. 1853 1853 The NEW MOON continues for one 1853 week after the change. 1854 1854 A CRESCENT is a figure resembling 1854 the new or increasing moon. (L., crescens, increasing.) 1854 1855 1855 1855 SECONDARY PLANETS, SATELLITES, or MOONs, are small planets revolving around some of the larger planets. (L., satelles, an attendant.) NOTE.-The Earth has one satellite; Jupiter, four; Uranus, six; and Saturn, eight. 5. Of the Moon. The HORNS are the points of the crescent moon. A HALF MOON is the figure of a moon cut in two. The FULL MOON occurs when the sun and the moon are situated on opposite sides of the earth, and the moon turns the illuminated half of her surface directly toward us. A QUARTER OF THE MOON is the fourth part of its monthly period. QUADRATURE is the position of one heavenly body in respect to another, The MOON is the satellite of our when distant from it ninety degrees. planet. NOTE.-The Moon's diameter is 2159 miles. Its bulk is one-forty-ninth part of that of the earth. It revolves around the earth in twentyseven days, seven hours, and forty-three minutes. 237,000 miles. The inclination of the Moon's Its mean distance from the Earth is orbit to that of the Earth is five degrees and fifty minutes. The PERIGEE is the point of the Moon's orbit which is nearest to the earth. ([peri], near; and " [ge], the earth.) NOTE. The moon is in her quadratures when at an equal distance from the points of conjunction and opposition. A MONTH is a period extending from one change of the moon to another. (from moon.) LUNA, the moon. (L.) Hence, Lunar, pertaining to the moon. Lunation, the period from one new moon to another. Lunacy, madness, from an idea BIELA'S COMET has a period of about which formerly prevailed, that the in- Sublunary, lit., situated beneath the moon. Hence, pertaining to this world. All sublunary things are subject to change. Dryden. 6. Of Eclipses. 8. Of the Zodiac. The ZODIAC is an imaginary belt extending eight degrees on each side of the ecliptic, which divides it in the middle. (Gr., Cadov [zodion], a little animal; because the constellations of An ECLIPSE consists in the ob- the ecliptic are, for the most part, scuration of the light of a celestial lu- represented in celestial charts by the minary. (Gr., a [ecleipo], to figures of animals.) The SIGNS OF THE ZODIAC are the NOTE 1.-Eclipses are of two kinds. First.-twelve equal portions into which the When the obscuration is caused by an intercep- Zodiac is divided by transverse lines. tion of the light received by the luminary from Second.--When the obscuration is (I., signum, a figure, in allusion to caused by an interception, either totally or par- the figures of animals, etc., with tially, of the light transmitted from the lumin- which the Zodiac is filled.) ary to the spectator.-Brande. fail.) the sun. NOTE 2. An eclipse of the sun is caused by an intervention of the moon between the earth and the sun. NOTE 3.-An eclipse of the moon is caused by the moon's passing through the shadow of the earth. Table of the Signs of the Zodiac. NOTE 4.-A solar eclipse can happen only at Taurus. the change of the moon, and a lunar eclipse can Gemini. happen only at the full of the moon. English Names. The Ram. The Twins. Cancer. The LIMB is the border or outer-Leo. The Crab. diameter of the sun or moon. 7. Of the Comets. Capricornus. The Goat. The Waterbearer. Symbols. The COMETS are bodies revolving Aquarius. around the sun in very eccentric Pisces. orbits, and are generally distinguished by a hair-like appendage called the tail. (Gr., noun [co'me], hair.) The HEAD, or NUCLEUS, is the denser portion of a comet. NOTE 1.-The tail of a comet is sometimes more than one hundred million of miles in length. NOTE 2-Comets, generally, if not always, consist of an inconceivably thin vapor. According to Sir John Herschell, stars of the smallest magnitude may, sometimes, be distinctly seen through the nucleus, or densest portion of a comet. NOTE 3.-The comets are supposed to be very numerous; yet there are only three whose periods are known; to wit: Halley's, Encke's, and Biela's. HALLEY'S COMET has a period of 75 years. ENCKE'S COMET has a period of about three years. The Fishes. Symbols of the Planets, etc. O The Sun. The Earth. • Juno. H Herschell. f Ceres. Pallas. 24 Jupiter. NOTE 1.-The sun passes through all the signs of the zodiac in one year. NOTE 2.-The moon passes through all the signs of the zodiac in each of its revolutions around the earth. The moon is, therefore, a little more than two days in passing through each sign. NOTE 3-When people look in the almanac for the sign, their object is to find the position of the moon among the constellations of the Zodiac. NOTE 4. The idea that the influence of the moon varies according to its position among the signs of the zodiac is unphilosophical, and in nothing but a vulgar prejudice. |