THE RENAISSANCE 127 



and described in terms of Ptolemaic cycles and epi- 

 cycles. But, inspired by the Copernican ideas, 

 Brahe, working on his island home off Copenhagen, 

 carried such observations to a higher degree of accuracy 

 than had ever before been known, and the accumula- 

 tions of his chequered lifetime fell into the hands 

 of an apt and eager follower. 



Working with Brahe's results, Kepler, whose 

 official occupation consisted chiefly in calculating 

 the astrological almanacks which, at that period, 

 were in favour at the petty courts of Germany and 

 Austria, after most laborious investigations, found a 

 series of laws which described the motion of the 

 planets. He showed, for instance, that they travelled 

 in paths which were ellipses, and that the sun was 

 at one of the two foci of the orbits, and this result, 

 with his other laws, led Newton to apply his unrivalled 

 mathematical powers to the planetary problem. 



But we must pause yet once more to trace another 

 influence in Newton's intellectual environment. The 

 Scientific number of those interested in natural 

 Academies, philosophy was now increasing rapidly, 

 and one sign of this increase was the establishment 

 of societies or academies consisting of men who met 

 together to discuss the new subjects and to further 

 their interests. The earliest of such societies appeared 

 at Naples in 1560 under the name of Academia Secret- 

 orum Naturae. In 1651 Florence followed by founding 

 the Accademia del Cimento. In England a society 

 began in 1645 to meet at Gresham College or elsewhere 

 in London. In 1648 most of its members moved to 

 Oxford owing to the Civil War, but in 1660 the meetings 



