Page:The American Cyclopædia (1879) Volume VI.djvu/400

392 ECLIPSE ECUADOR satellite, the event is called an occultation of the satellite ; but when a satellite of Jupiter hides a portion of the planet, a transit of the satellite is said to be in progress ; and when Venus or Mercury hides a portion of the sun's face, a transit of Venus or Mercury is said to be in progress. Events of the second kind are called eclipses in nearly all cases, but occasion- ally the transit of a shadow. Thus if the earth's shadow fulls upon the moon, so as to obscure her face either wholly or partially, the phenomenon is called an eclipse of the moon ; so also if the shadow of Jupiter or Sat- urn obscures a satellite of either planet, the phenomenon is called an eclipse of the satellite ; but when the shadow of a satellite of either planet falls upon the planet, a transit of the shadow is said to be in progress. For the prin- cipal phenomena presented during a solar eclipse, see SUN. It is only necessary to men- tion here that, owing to the various distances of the sun and moon, a solar eclipse may be total or annular when central ; that is, either the whole face of the sun may be concealed, or a ring of the sun's light may remain visible all round the disk of the moon. When the eclipse is not central, so that at the moment of great- est obscuration a crescent-shaped portion of the sun remains visible, the eclipse is said to be partial. In lunar eclipses the shadow of the earth seldom falls very nearly centrally upon the moon ; yet owing to its great breadth at the moon's distance, the moon is often total- ly immersed in the shadow. When this hap- pens the phenomenon is called a total lunar eclipse. When the moon passes only in part into the earth's true shadow the phenomenon is called a partial lunar eclipse. As the earth's shadow is surrounded by a penumbra, it occa- sionally happens that the moon passes partly within the penumbra without reaching the true shadow. Such phenomena have been call- ed penumbral lunar eclipses. It might be sup- posed that when the moon is totally immersed in the true shadow of the earth she is totally obliterated from view; but this seldom hap- pens. Usually the moon in the heart of the earth's shadow presents a dark red or copper- colored disk. It is believed that the light which thus illuminates her is sunlight which has undergone refraction by the earth's atmos- phere. Indeed, it is demonstrable that if the moon is centrally eclipsed, even when she is nearest to the earth, a visual line from any point of the moon tangential to the earth's globe would be so bent by refraction in its pas- sage through the earth's atmosphere as to reach the sun's disk ; so that an inhabitant of the moon would see a ring of reflected sunlight all round the earth's disk during one of these to- tal eclipses. But this would not happen if all those parts of the terrestrial atmosphere which bordered on the earth's visible half were cloud- laden ; and this is believed to be the reason why occasionally the moon disappears wholly from view when totally eclipsed. ECLIPTIC, the great circle of the heavens along which the sun appears to travel in the course of a year. It is inclined at an angle of about 23 28' to the celestial equator. The name is derived from the fact that the light of the sun or moon can only "pass away" when the moon is on or near the ecliptic. The ecliptic is divided by astronomers into 12 equal por- tions, each of 30. These are called signs, and supply the means of indicating the annual pro- gression of the sun. They commence with the point where the ecliptic crosses the equator passing from south to north. This point is called the first point of Aries, and is indicated by the sign J> ; and Aries extends 30 along the ecliptic eastwardly, that is, in the direction of the sun's motion, from this point. Then follow successively the signs Taurus y , Gemi- ni n, Cancer , Leo SI, Virgo TTJJ, Libra ~=, Scorpio ill, Sagittarius $, Capricornus , Aquarius Xw', and Pisces ^ . These signs, whe- ther regarded as ecliptical or zodiacal, are not identical with the corresponding zodiacal con- stellations, each of which, owing to precession, has been carried so far forward as to agree very nearly with the next sign. Thus the con- stellation Pisces corresponds very nearly with the sign Aries, the constellation Aries with the sign Taurus, and so on. The sun enters Aries at the vernal equinox, on or about March 21, Taurus on or about April 20, Gemini on or about May 21, Cancer on or about June 21 (the summer solstice), Leo on or about July 22, Virgo on or about Aug. 23, Libra on or about Sept. 23 (the autumnal equinox), Scorpio on or about Oct. 23, Sagittarius on or about Nov. 22, Capricornus on or about Dec. 21 (the winter solstice), Aquarius on or about Jan. 20, and Pisces on or about Feb. 19. ECUADOR^ a republic of South America, named from its situation under the equator. It lies between lat. 1 50' K and 5 30' S., and Ion. 69 52' and 80 35' W., and is bounded N. by the United States of Colombia and Brazil, E. by Brazil, S. by Peru, and W. by the Pacific. The Ecuadorians assert their right to the prov- ince of Mainas, S. of the Maraflon ; but most geographers assign that river as the greater portion of the southern boundary, adopting for the northern a right line drawn from the northernmost mouth of the river Mira E. by S. to the Caqueta or Japura, some 30 m. below the confluence of the Mesai, the Caqueta itself forming the remainder of the boundary to Ion. 69 52' W. The extreme length of the republic would thus be about 740 m. from E. to W., and the greatest breadth 620 m. from N. to S. The area, according to the best estimates, is about 252,000 sq. m., and that of the Galapagos islands 2,951, making a total area of 254,951 sq. m. The coast presents a sinuous convex line, about TOO m. long, with a general bearing from S. W. to N. E. Principal among the nu- merous indentations is that formed by -the gulf of Guayaquil, 80 m. wide, at the mouth of the river of the same name. Further northward