Astronomy in a nutshell, the chief facts and principles explained in popular language for the general reader and for schools . and night are ofequal length all over the earth. (Equinoxis from two Latin words meaning equalnight.) We shall have more to say about theequinoxes later, but for the present it issufficient to remark that one of these points—that one where the sun is about the 21stof March, which is the beginning of astro-nomical spring—is the Greenwich of theSky, or the vernal equinox. The other,opposite, point is called the autumnalequinox, because the sun arrives thereabout the 23d
Astronomy in a nutshell, the chief facts and principles explained in popular language for the general reader and for schools . and night are ofequal length all over the earth. (Equinoxis from two Latin words meaning equalnight.) We shall have more to say about theequinoxes later, but for the present it issufficient to remark that one of these points—that one where the sun is about the 21stof March, which is the beginning of astro-nomical spring—is the Greenwich of theSky, or the vernal equinox. The other,opposite, point is called the autumnalequinox, because the sun arrives thereabout the 23d of September, the beginningof astronomical autumn. The vernal equi-nox, as we have already seen, serves as apointer on the dial of the sky. When itcrosses the meridian of any place it isastronomical noon at that place. Itsposition in the sky is not marked by anyparticular star, but it is situated in theconstellation Pisces, and lies exactly at thecrossing point of the celestial equator andthe ecliptic. The hour circle, running throughthis point, and through its opposite, theautumnal equinox, is the prime meridian of. Saturn From a drawing by Trouvelot.
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Keywords: ., bookcentury1900, bookdecade19, booksubjectastronomy, bookyear1912
