XVlll SUMMARY OF THE CONTENTS. 



urements of degrees and pendulum experiments in different latitudes. 

 Compression. The figure of the earth was known to Newton on theo. 

 retical grounds, and the force discovered, of the operation of which tho 

 laws of Kepler are a necessary consequence. The discovery of such a 

 force, w^hose existence is developed in Newton's imperishable work 

 Principia, was nearly simultaneous with the opening of new paths to 

 mathematical discovery by the invention of the infinitesimal calculus — 

 p. 331-352. 



VIIT. Retrospect, Multiplicity, and intimate Connection existing among 

 the Scientific Efforts of Modern Times. — Retrospect of the principal 

 momenta in the history of cosraical contemplation connected with great 

 events. The multiplicity of the links of connection among the different 

 branches of science in the present day increases the difficulty of separ- 

 ating and limiting the individual portions — Intellectual activity hence- 

 forth produces great results almost without any external incitement, 

 and by its own internal power manifested in every directic n. The hi»« 

 lory of the physical sciences gradually fuses into that of the idea cf 

 Universal Nature— p. 352-356. 



