70 FIXED STARS, &c. [Lesson XV. 



The last star in the tail of Ursa Minor, or the 

 Less Bear, is called the Polar Star, and serves 

 for a guide to mariners ; because, on account of 

 its nearness to the north pole, its apparent situa- 

 tion, with regard to the Earth, varies but very 

 little throughout the period of the Earth's annual 

 revolution. Two of the stars in the constellation 

 of Ursa Major) or the Greater Bear, are called 



the centre of the second projection is the South pole of the 

 Ecliptic, where all the Circles of Latitude meet and intersect, 

 as in the Southern Hemisphere. From the Poles of the 

 Ecliptic as centres, the Circles of Longitude are drawn at 

 every tenth degree: that circle which is described at 90* 

 from each pole of the Ecliptic, is the Ecliptic itself ; of 

 this, half appears in the one projection, and half in the 

 other; it interests the Equator in the fiist points of Arits() 

 and Libra (:). The diameter of each projection which 

 crosses it from top to bottom, is called the Solstitial Colure, 

 because it passes through the solstitial points, Cancer (25) 

 and Capricorn (Vf} ' the diameter that crosses each projection 

 from right to left denotes the Equinoctial Colure, so called be- 

 cause it passes through the equinoctial points. Ariet and 

 Libra. These four points of the Ecliptic which are crossed 

 by the Colures are called Cardinal Points; and when the Sun 

 enters one or other of these points, one of the four Seasons 

 of the year commenc( s. 



The Stars are given in this plate as they appear on the sur- 

 face of the Celestial Globe, with this difference, that the 

 figures of the Constellations are omitted, as they would only 

 tend to create confusion when the Hemispheres arc projected 

 on so small a scale. The Stars of different magnitudes are so 

 distinguished, that with little difficulty they may be reckoned 

 in many instances : Thus, in Ursa Minor, or the Less Hear, it is 

 easy to reckon two stars of the second, one of the third, three 

 of the fourth, one of the fifth, and three of the sixth magnitude. 

 Again, in Cunicula, or the Little Dog, you may discover ten 

 stars, whereof one, called Procyon, is of the first magnitude. 



the 



