488 SPECIAL METHODS OF DISCOVERY. 



a body, falling from a height, descended more and more 

 quickly until it reached the ground ; and by investigating 

 this circumstance he succeeded in discovering the law of 

 falling bodies, i.e., what the rate of increase of velocity 

 of falling was for each additional second of time of 

 descent. 



Bode having, from calculations, inferred the existence 

 of the orbit of a missing planet between those of Mars 

 and Jupiter, it was resolved at a meeting of Grerman 

 astronomers at Lilienthal in Saxony, in the year 1800, to 

 investigate this peculiar circumstance, and search for the 

 supposed missing body. Piazzi, astronomer in the obser- 

 vatory at Palermo, sought for it, and during the first 

 night of the year 1801 he observed a previously un- 

 noticed small star in the constellation Taurus. He soon 

 found that it changed its place. He now became ill, and 

 no one could find the star again ; but Gauss, from the 

 facts which Piazzi had given, calculated where it should 

 be, looked there, and found it. Thus was the discovery 

 of Ceres made, the first of the asteroids. In 1802, Dr. 

 Olbers, of Bremen, discovered another asteroid near Ceres, 

 and called it Pallas. And, in 1804, Harding discovered 

 Juno. Olbers then inferred and suggested the existence 

 of an exploded planet, because all these asteroids or small 

 planets were about equidistant from the sun ; and in 

 1807 a fourth was found, which he called Vesta. And 

 since that time additional ones have been occasionally 

 discovered, until we now know more than 150, all moving 

 round the sun, between the orbits of Mars and Jupiter, in 

 the space which, according to Bode's law, ought to contain 

 a planet. Some of these asteroids are exceedingly small, 

 being only a few miles in diameter. Pallas is the largest 

 yet found, and is about 600 miles in diameter. 



The persistent investigation of the singular property 



