YVUl 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 the 

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

 force, whose existence is developed in Newton's imperishable work 

 Principia, w^as nearly simultaneous with the opening of new paths to 

 mathematical discovery by the invention of the infinitesimal calculus — 

 p. 331-352. 



VIII. Retrospect, Multiplicity, and intimate Connection existing among 

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

 momenta in the history of cosmical contemplation connected with great 

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

 branches of science in the present day increases the diflHculty 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 direction. The his- 

 tory of the physical sciences gradually fuses into that of the idea of 

 Universal Nature — p. 352-356. 



