CONTENTS. 



CHAPTER XXIX. 



SCIENCE OF THE EIGHTEENTH CENTURY (CONTINUED). 



PAGE 



Benjamin Franklin, born 1706 His Early Life Du Faye dis- 

 covers two kinds of Electricity Franklin proves that Electricity 

 exists in all Bodies, and is only developed by Friction Positive 

 and Negative Electricity Franklin draws down Electricity from 

 the Sky Invents Lightning-conductors Discovery of Animal 

 Electricity by Galvani Controversy between Galvani and Volta 

 Volta proves that Electricity can be produced by the Contact 

 of two Metals Electrical Batteries The Crown of Cups The 

 Voltaic Pile 2^3 



CHAPTER XXX. 



SCIENCE OF THE EIGHTEENTH CENTURY (CONTINUED). 



Bradley and Delisle, Astronomers Aberration of the Fixed Stars 

 Nutation of the Axis of the Earth, Delisle's Method of Mea- 

 suring the Transit of Venus Lagrange and Laplace Libration 

 of the Moon accounted for by Lagrange Laplace works out the 

 Long Inequality of Jupiter and Saturn Lagrange proves the 

 Stability of the Orbits of the Planets Sir William Herschel 

 constructs his own Telescopes Discovery of a New Planet 

 Discovery of Binary Stars Herschel studies Star-clusters and 

 Nebulae Theory of Nebulae being matter out of which Stars 

 are made The Motion of our Solar System through Space 

 Weight of the Earth determined by the Schehallien Experiment 

 Summary of the Science of the Eighteenth Century . . 265 



CHAPTER XXXI. 



SCIENCE OF THE NINETEENTH CENTURY. 



Difficulties of Contemporary History Discovery of Asteroids and 

 Minor Planets between Mars and Jupiter Dr. Gibers suggests 

 they maybe fragments of a larger Planet Encke's Comet, and 

 the correction of the size of Jupiter and Mercury Biela's 

 Comet, noticed in 1826 It divides into two Comets in 1845 



