PART the FIFTH. 



Of the System of the World: of the Heavenly 

 Bodies ; and of the Properties and Causes 

 of Natural Bodies. 



CHAP, I. 



Of the System of the World. 



1. The general phenomena of the sun and moon 219 



2. Of mercury and venus . . 220 



3. Of the other planets : mars, jupiter, and saturn ib. 



4. Of the comets and fixed stars , . ib. 



5. The Ptolemaic system . . ib 



6. The Copernican system . . 221 



7. The system of TychoBrahe . . 222 



8. The Hu4chinsonian system . 223 

 $>. The advantages of the rotation of the earth 22? 



CHAP. II. 



Of the Heavenly Bodies in particular. 



Of the sun . . 230 



Mr. Huygeas's observations on the sun , 33, 



