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Big Dipper will be directly- below the north star. At 6 A.h. the left-hand side should be at the bottom, and the Dipper will be above Polaris. From day to day this aspect will change, each star coming
a little earlier to the meridian, or to its position on the preceding night. The rate of this progression is six hours, or 90°, in three months.
TJr&a Major is represented under the figure of a great bear. It contains 138 stars visible to the naked eye. The constellation has been celebrated among all nations. It is remarkable that the shepherds of Chaldea in Asia, and the Iroquois Indians of America, gave to it the same name.
Principal stars.—A noticeable cluster of seven stare—six of the second and one of the fourth magnitude—forms what is familiarly termed " The Dipper." In England it is styled Charles's Wain, from a fancied resemblance to a wagon drawn by three horses tandem. Mizar (£) has a minute companion, Alcor, which Humboldt tells us could be rarely seen in Europe. A person with good eyesight may now readily detect it. Megrez (5), at the junction of the handle and the bowl, is to be marked particularly, since it lies almost exactly in the colure passing through the autumnal equinox. Dubhe and Merak are termed " The Pointers," since they always point out the polar star. The bear's right fore paw and hinder paw are each marked by two small stars, as shown in the cut; a similar pair nearly in line with these denote the left hinder paw (see S, Fig. 76). The pairs are 15° apart.
Mythological history.—Diana had a very beautiful attendant named Callisto. Juno, the queen of heaven, becoming jealous of the maid, transformed her into a bear.
"The prostrate wretch lifts up her head in prayer,
And lent the supplicating brute might reach
Some time afterward, Callisto's son, Areas, being out hunting, pursued his mother and was about to transfix her with his uplifted spear, when Jupiter in pity transferred them both to the heavens, and placed them among the constellations as Ursa Major and Ursa Minor.
Ursa Minor is represented under the figure of a small bear. It contains twenty-four stars, of which only three are of the third, and four of the fourth magnitude.
Principal stars.— A cluster of seven stars forms what is termed the " Little Dipper." Three of them are small, and are seen with difficulty. Polaris, at the extremity of the handle, has been known from time immemorial as the North Polar Star. Among the Greeks it was styled Cynosure. Until the mariner's compass came into use, it was the star
u Whose faithful beams conduct the wandering ship
Polaris does not mark the exact position of the pole, since that is about toward the Pointers. This distance will gradually diminish, until in time it will be only £°: then it will increase again, until in the lapse of ages—12,000 years hence—the brilliant star a Lyra will fulfil the office of polar star for those who shall then live on the earth.
Curious fact concerning the Pyramids.—Of the nine Pyramids which are standing at Gizeh, Egypt, six have openings facing the north. These lead to straight passages which descend at a uniform angle of about 26° and are parallel with the meridian. If we suppose a person, 4000 years ago, standing at the lower end of one of these passages, and looking out, his eye would strike the sky near the star Thuban, which was then the polar star. The supposed date of the building of these Pyramids (2123 B. c.) agrees with that epoch, and very naturally suggests that the builders had some special design in this peculiar construction.
The distance of Polaris is so great, that though the star is moving through space at the rate of ninety miles per minute, this tremendous speed is imperceptible to us. It requires nearly fifty years for its light to reach the earth; so that when we look at Polaris, we know that the ray which strikes our eye set out on its journey through space half a century ago. We cannot state positively that the star is now in existence, since if it were destroyed to-day it would be fifty years before we should miss it.
Calculation of latitude from Polaris.—By an observer at the equator, Polaris is seen at the horizon. If he advances north, the horizon is depressed and Polaris seems to rise in the heavens. When it has reached the height of a degree, the observer is said to have passed over a degree of latitude on the earth's surface. As he moves further north, the polar star continues to ascend; its distance above the horizon denoting the latitude of each place in succession, until at the north pole, if one could reach that point, Polaris would be seeD directly overhead.
Draco is represented under the figure of a long sinuous serpent, stretching between Ursa Major and Ursa Minor, nearly encircling the latter constellation, and finally reaching out its head almost to the body of Hercules.
Principal stars.—Four small stars form a quadrilateral figure at the head; a fifth of the fourth magnitude which is scarcely visible, marks the end of the nose; several scattered groups and delicate triangles of small stars, denote the position of the various coils of the body; thence, an irregular line of stars traces the dragon's tail around between Ursa Major and Ursa Minor. Thuban lying midway between 7 of the Little Dipper and £ of the Big Dipper, is noted as the polar star of forty centuries ago.
Mythological history.—Many accounts are given of the origin of this constellation, as indeed there are of almost every one in the heavens. The prevalent opinion is, that it is the dragon which Cadmus slew. The story is as follows. Jupiter had carried off Europa. Agenor, her father, sent her brother Cadmus in pursuit of his lost sister, bidding him not to return until he was successful in his search. Affer a