DOES THE POLE-STAR CHANGE* 21 



" Nee paribus positse sunt frontibus ; utraque caudain 

 Vergit in alterius rostrum, sequiturque sequentem." * 



Not in the same direction do they face : 

 The one its tail towards the other's snout 

 Turns, and they thus, pursuing, each pursue. 



Certain it is that the Phoenicians, as experienced seamen, 

 would guide their course by the constellation lying nearest 

 to the pole. But was this constellation the same which we 

 now-a-days call Ursa Minor ? It is quite allowable for us to 

 put such a question, because everybody knows that, owing to 

 the movement of the terrestrial axis around the poles of the 

 ecliptic, the axis of the world (the terrestrial axis prolonged) 

 is displaced to an extent which becomes perfectly appreciable 

 at the end of a certain time.f We may calculate, therefore, 

 that the pole, now situated, as we have already said, near the 

 star Polaris (a in Ursa Minor), was formerly at some distance 

 from it. So, at the epoch of the greatest prosperity of the 

 Phoenician people, or about three thousand years ago, the 

 north pole would nearly correspond with a star in Draco, 

 now 24 52' distant. 



[This constellation is shown in fig. T, between Ursa Major 

 and Ursa Minor ; the in Draco is a star surrounded by a 

 circle, like the Polar Star, a in Ursa Minor.] 



That the constellation of Draco was well known to the 



* Manilius, " Astronomicon," i. 308, 309. 



*f* This displacement amounts to about fifty seconds annually, or, more 

 accurately, to 5o".3. It is easy, therefore, to calculate that the complete 

 rotation of the terrestrial axis around the poles of the ecliptic will occupy 

 25,765 years. 



