HOW TO OBSERVE THE HEAVENS. 



the earliest times many others of inferior, splendour, and this 

 number has been gradually augmented as the range and accuracy 

 of observations have been increased by the improvement of tele- 

 scopes. From the era of Ptolemy, A.D. 150, to that of Copernicus, 

 A.D. 1500, this constellation contained 35 stars. In the time of 

 Kepler, A.D. 1600, the number was augmented to 56. In Flam- 

 stead's Catalogue, A.D. 1700, the number was further augmented 

 to 87, and, in fine, at the beginning of the present century, it was 

 increased to 338. 



The constellation, including the stars composing it so far as they 

 are visible without a telescope, is shown in fig. 2, p. 145, where the 

 position and form of the imaginary figure of the bear relatively to 

 the stars are indicated. It will be seen that the four stars 

 o & 7 and 8 are upon the side, the three others marking the tail. 



16. It will be observed in fig. 2 that the principal stars of the 

 constellation, besides being indicated by the Greek letters, are 

 also designated by certain proper names, mostly of Arabic or 

 Oriental origin ; and it may here be stated in general that besides 

 the method of designating stars by naming the constellation to 

 which they belong, and the letter which distinguishes them in 

 such constellation, most of the conspicuous stars have received 

 proper names which probably were conferred upon them before 

 the system of constellations was established ; and many of these 

 stars are now much more frequently designated by these proper 

 names than by that which connects them with the constellation. 

 Thus, for example, the most splendid star in the constellation of 

 Canis major or the greater Dog, instead of being called a Cam's 

 majoris, which would be its name in the nomenclature of the 

 constellations, is almost invariably called Sirius. In the same 

 manner, the principal star of the constellation Leo, is always 

 called Regulus and never a Leonis. 



These observations, however, are not applicable in the same 

 manner to the seven principal stars of Ursa major, which are 

 more generally designated by the Greek letters which connect 

 them with the constellation. 



17. The position of the stars composing a constellation is also 

 frequently indicated by naming the part of the imaginary figure 

 designating the constellation at which the star is found. Thus, 

 for example, the position of i\ Ursee majoris, is indicated by 

 stating that it is at the tip of the tail. In like manner, the 

 position of a certain star in the constellation Taurus, is indicated 

 by stating that it is in the "bull's eye." This form of expres- 

 sion, which is in very frequent use with astronomers, seems to 

 render it unadvisable to efface altogether from maps of the stars 

 the figures designating the constellations, as is sometimes done. 



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