viii CONTENTS OF THE SECOND VOLUME. 

 CHAPTER VI. THE INSTRUMENTS AND AIDS OF ASTRONOMY 



DURING THE NEWTONIAN PERIOD. 



PAGE 



Sect. 1. Instruments ... . 272 



Sect. 2. Observatories 



Sect. 3. Scientific Societies 



Sect. 4. Patrons of Astronomy ..... 



Sect. 5. Astronomical Expeditions . 



Sect. 6. Present State of Astronomy . . 290 



THE SECONDARY MECHANICAL SCIENCES. 



BOOK VIII. 



HISTORY OF ACOUSTICS 

 Introduction ......... 323 



CHAPTER I. PRELUDE TO THE SOLUTION OF PROBLEMS IN 



ACOUSTICS .... 325 



CHAPTER II. PROBLEM OF THE VIBRATIONS OF STRINGS . 332 

 CHAPTER III. PROBLEM OF THE PROPAGATION OF SOUND 340 



CHAPTER IV. PROBLEM OF DIFFERENT SOUNDS OF THE 



SAME STRING .... 348 



CHAPTER V. PROBLEM OF THE SOUNDS OF PIPES . 352 



CHAPTER VI. PROBLEM OF DIFFERENT MODES OF VIBRA- 

 TION OF BODIES IN GENFJIAL . .357 



BOOK IX. 

 HISTORY OF OPTICS, FORMAL AND PHYSICAL. 



Introduction 37J 







FORMAL OPTICS: 

 CHAPTER I. PRIMARY INDUCTION OF OPTICS. RAYS OF 



LIGHT AND LAWS OF REFLECTION . . 374 



CHAPTER II. DISCOVERY OF THE LAW OF REFRACTION . 37<i 



