CONTENTS. xvii 



CHAPTER IX. 

 THE SCIENTISTS OF THE XVTH AND XVlTH CENTURIES. 



PAGE 



Mathematicians ; naturalists ; anatomists and physiologists ; 

 observers ; Experimentalists Tycho Brahe, Gilbert, Harvey 

 Special eminence of Leonardo da Vinci and of Galileo The 

 latter discovers the permanency of Law ; formulates the three 

 laws of motion ; reveals the immensity of the Universe with the 

 telescope Kepler's laws Leonardo da Vinci's injunctions to 

 rely upon experiment, induction, and verification Bacon 

 denounces these achievements and opposes his own to them . 96 



CHAPTER X. 

 MODERN SCIENCE. 



Difficulty of such a survey Vastness of the subject Classification 

 of the Sciences by Comte ; by Spencer First Group : Botanists, 

 Anatomists, and Palaeontologists, Physiologists, Biologists, 

 Anthropologists, Philologists, Sociologists : their discoveries . 109 



Second Group Geologists, Physical Geographers, and their 

 discoveries . . . . . . . : ../,, . . 159 



Third Group Chemists, and their discoveries "Y l- . . . 172 

 Fourth Group Mathematicians, and their discoveries . . .191 

 Fifth Group Astronomers, and their discoveries .... 198 

 Sixth Group Physicists, and their discoveries . . . "... 215 

 Seventh Group Eminent practical men, and their inventions . 260 



CHAPTER XI. 

 THE VALUE OF INSTRUMENTS. 



Instruments among the ancients They add power to the senses 

 Impossibility of scientific advancement without them The 

 telescope ; the microscope ; the prism ; the thermometer ; the 

 compass ; the pendulum ; the barometer ; lenses ; the camera 

 obscura; the battery ; mathematics The importance of cork, 

 glass, etc. Accuracy -of instruments 266 



b 



