THE GENESIS OF THE LAW OP GRAVITY 325 



Keplbb 



who, after the death of the king, stripped the astronomer of all his 

 estates and drove him penniless from the kingdom. For two years he 

 was without a home, but in 1599 found refuge and a pension with 

 Emperor Rudolph II., of Bohemia. Becoming established in Prague, 

 he set up his instruments, and soon students flocked to him again. 

 Among them came the poor youth, Kepler, who soon made himself 

 invaluable to his master. In return, Tycho was kind to Kepler, and 

 together they labored until the former's death in 1601. 



With the advent of Kepler (1571-1630) the real problem of gravity 

 together with its solution took definite form. Always a firm believer 

 in the unity and simplicity of the solar system, Kepler rejected the 

 teaching of Tycho Brahe and adopted Copernicus's scheme in toto. 

 Next, he set about bringing order out of the mass of observations ae- 



