ECLIPSE (Lat. ec/ipRis, from (1k. i'KXeoPts, c1Icipsis, eclipse, from ifiXehretp, ekicipein, to for• sake, fail, from IK out Xthretv, let petit, to leaNe). Sometimes one or other of the self luminous beaNenly bodies is shut ill from our new temporarily by the interposition of some other body between it and the earth. This is called an eclipse when the object temporarily ohseured is the sun, and an occultation (q.v.) when it is a star. Non-luminous bodies. whieh shine only by reflecting solar light• may be 'eclipsed' by having the light cut off by a body passing between themselves and the sun: and they may be 'occulted' by being concealed behind a body passing between theniselves and the earth. The term 'transit' is applied to the partial con cealment of the sun by the passage_ across his face of Venus or and to the similar phenomena of•the passages of Jupiter's satellites across his disk. The causes of eclipse as here suggested are so simple and familiar that it is difficult for us to imagine how deeply eclipses affected men's minds before the dawn of astro nomical science. At Home. at one time, it was blasidiemy, and punished by law, to talk publicly of their being due to natural causes. According to some, Luna, when in eclipse, was in the pains of labor; according to others, she was suffering from the arts of wicked magicians. The Chinese imagine eclipses to be caused by great dragons trying to devour the sun and moon, and accord ingly they bent drums and brass kettles to ter rify the monsters into letting go their prey. Solar eclipses can occur only at the time of new moon, when the sun and moon are in con junction on the same side of the earth. In a
partial eclipse, the sun's disk suddenly loses its circular form; it, becomes indented on one side, the indentation slowly increasing for some time, and thCn diminishing until it disappears alto gether. In a total eclipse, the indentation goes on increasing till the whole orb disappears for a time; after a short interval, the sun reappears again, passing through the same phases of obseuration in an inverse order. In an annular eclipse, the whole sun is obscured except a ring or annulus. Lunar eclipses. on the other hand, always occur at full moon, or when the sun and moon are in opposition. and are caused by the moon passing through the earth's shadow. Suel, eclipses are sometimes partial and sometimes total, but never annular, and in their general phases they resemble those of the sun. The duration of an eclipse is the time of its con tinuance, or the interval between immersion and emersion. Immersion. or incidence, of an eclipse is the moment part of the luminary begins to be obscured; emersion is the time when the luminary begins to reappear or emerge from the When the size of an eclipse is men tioned, the part of the luminary obscured is ob tained by dividing its diameter into twelve digits; and the eclipse is said to he of so many according to the number of them eontained in that part of the diameter which is obscured.