CH. xxxii. ASTEROIDS OR MINOR PLANETS. 299 



of the nature of the sun, planets, stars, comets, meteors, 

 etc., telling us what they are like in themselves, whether they 

 have an atmosphere like our own, and of what materials 

 they are made. This study has been carried on partly by 

 powerful telescopes, but chiefly by the wonderful method 

 called spectrum analysis, of which we shall speak presently. 

 Meanwhile we must first begin by naming a few new bodies 

 lately observed in the heavens. 



Discovery of the Asteroids and Minor Planets be- 

 tween Mars and Jupiter, 1801-18O7. Not long after the 

 discovery of Uranus, a well-known astronomer named Bode 

 pointed out that the distances of the planets from the sun 

 seemed to follow a remarkable arithmetical law. The only 

 exception to this law was between Jupiter and Mars ; and 

 here the gap was twice as large as it ought to be according 

 to the calculation. Therefore astronomers suspected (as 

 indeed Kepler had suggested more than 200 years before) 

 that there must be a planet between these two which had 

 not yet been seen; and in the year 1800, at a meeting 

 at Lilienthal, in Saxony, they agreed to search diligently for 

 this supposed missing body. 



Signer Piazzi, the Astronomer of the Observatory at 

 Palermo, in Sicily, was one of these planet-seekers, and on 

 the first night of the year 1801 he caught sight of a small 

 star in the constellation Taurus, which had not yet been 

 noticed in any catalogue. The next night he looked for it 

 again, and found that it had moved its position. He did 

 this for twelve nights, and the movement seemed to show 

 that it must be the planet he was seeking. Just at this point, 

 however, he was taken ill, and although he had told other 

 astronomers of what he had seen, no one could find the 

 planet again. Months passed, and people began to doubt 

 whether he had not made a mistake ; but at last a young 



