692 THE UNIVERSE. 



raise the spirit of man from the visible to the invisible. 

 The heavens relate the glory of God : Call enarrant glo- 

 riam Dei. 



The number of known stars, the orbits of which have 

 been calculated, is considerable. Astronomers compute the 

 number that can be seen by the naked eye on the horizon 

 at the same moment at 3000. The sharpest sight, favored 

 by an extremely clear night, can only number nearly 

 6000. 1 



This starry wealth became embarrassing, and at a very 

 early period, for more convenient study, the necessity was 

 felt for making distinct groups, to which the name of con- 

 stellations was given. Nearly all these assemblages are 

 named after living beings, sketched out on the celestial 

 sphere. 



But this grouping into constellations, the origin of which 

 goes far back into antiquity, has only been carried out by 

 successive attempts. According to Clement of Alexandria, 

 it was Chiron, the preceptor of Jason, who, 1420 years be- 

 fore our era, first divided the starry sky into distinct con- 

 stellations, tracing them out on a sphere which he pre- 

 sented to the Argonauts. Such is also Newton's opinion. 2 



1 Argelander, director of the observatory of Bonn, says, in his Nouvelle Urano- 

 metrie, that on the horizon of Berlin 3256 stars are seen with the naked eye in 

 the course of a year. A Munster astronomer, M. Heis, asserts that his sight is so 

 penetrating that he can see 4000 more than his brother worker. According to 

 Humboldt 4146 are counted at Paris. But the difference becomes very great so 

 soon as we examine the sky with even feeble instruments. Thus in a corner of a 

 constellation of the Twins, where the most practised eye can only make out six 

 stars, a good glass shows a mass of more than 3000. 



2 Several of the constellations, however, are already mentioned in the Bible at 

 an epoch anterior by some years to that in which the celebrated Centaur is said 



