CONTENTS 



opes of Galileo and Kepler, p. 253 The application of the 

 inuT-Miu -tor to the telescope, p. 254 Revolutionary effect of this 

 adapt. it imi, p. 255 Huygens's invention of the pendulum clock, p. 

 256 The application of the coiled spring for regulating watches 

 and marine clocks, p. 257 The invention of the sextant, and its 

 effect upon navigation, p. 257 Improvement of the microscope, 

 p. 258- 



CHAPTER XIV 



PROGRESS IN ELECTRICITY FROM GILBERT AND VON GUERICKE TO 



FRANKLIN 



The experiments of Francis Hauksbee, p. 259 Stephen Gray and 

 the discovery of electrical conduction, p. 262 His experiments 

 with long conducting-cords, p. 263 His discovery that silk was a 

 non-conductor, p. 266 The experiments of Dufay, p. 267 His 

 discovery of insulation, p. 270 His discovery of vitreous and res- 

 inous electricity, p . 2 7 2 Spectacular experiments of George Matthias 

 Bose, p. 274 Ludolff's proof that the electric spark is fire, p. 276 

 Gordon's invention of an electric bell and motor, p. 279 Von 

 Kleist invents the Leyden jar, p. 280 Benjamin Franklin and his 

 experiments for drawing off and throwing off electricity, p. 286 

 His battery, p. 289 His invention of the lightning-rod, p. 290 

 His proof that lightning is electricity, p. 293. 



CHAPTER XV 



NATURAL HISTORY TO THE TIME OF LINN^US 



The immediate predecessors of Linnaeus, p. 297 The discoveries 

 of Malpighi, p. 297 Nehemiah Grew's Anatomy of Vegetables, p. 

 298 Discoveries of Robert Hooke and Stephen Hales, p. 298 The 

 classifications of Ray, Rivinus, Camerarius, and Tournefort, p. 

 299 -The coming of Linnaeus, p. 299 His famous system of 

 classification, p. 301. 



APPENDIX . . 305 



