The Milky Way 



queer forms, into which the sky has been divided 

 up only betray our inability to unravel its chaos, 

 which grows more inextricable as we look 

 deeper into it. 



There are about six thousand stars visible 

 to the naked eye those, namely, which are 

 classified in the first six orders of magnitude. 1 

 Good telescopes enable us to see stars down 

 to the eleventh magnitude and show several 

 million stars in the sky. Her setters celebrated 

 telescope, the most powerful instrument ever 

 constructed, enabled one to see a distance of 

 a thousand million diameters of the terrestrial 



J The magnitude of two stars is said to differ by one 

 magnitude when the ratio of their luminous intensities, seen 

 from the earth, is 2.5. Thus stars of the second magnitude 

 are two and a half times as bright as stars of the third magni- 

 tude and two and a half times less bright than those of the first 

 magnitude. It is possible to prolong this scale of magnitudes 

 on both sides by the use of negative numbers. Thus Aldebaran, 

 in the constellation Taurus, being selected to define the first 

 magnitude, the small star 70 of the Whale, which can barely be 

 distinguished by the naked eye, would be of the sixth magni- 

 tude Vega of the Lyre, which is brighter than Aldebaran, 

 would be characterised by 0.2, Arcturus by the cipher o, and 

 Sirius, which is still brighter, becomes of the i.4th magnitude. 

 The sun, measured on the same scale, would be a star of 27th 

 magnitude, i.e., it sends us seventy thousand million times as 

 much light as Vega. 



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