CONTENTS. 



PACK 



observed by Wollaston Mapped by Fraunhofer Life of 

 Fraunhofer He discovers that the Dark Lines are different 

 in Sun-light and Star-light Experiments on the Spectra of 

 different Flames Four new Metals discovered by Spectrum 

 Analysis Artificial Dark Lines produced in the Spectrum by 

 Sir David Brewster Bunsen and Kirchhoff explain the Dark 

 Lines in the Solar Spectrum Metals in the Atmosphere of 

 the Sun Photosphere Corona Jannsen and Lockyer on 

 Red Prominences Chromosphere Huggins and Miller ex- 

 amine the Stars and Nebulae by Spectrum Analysis Spectra 

 of Comets Travelling Stars Celestial Photography . . 330 



CHAPTER XXXV. 



SCIENCE OF THE NINETEENTH CENTURY (CONTINUED). 



Early Theories about Heat Count Rumford shows that Heat 

 can be produced by Friction He makes Water boil by boring 

 a Cannon Davy makes two pieces of Ice melt by Friction 

 His conclusion about Heat How ' Latent Heat ' is explained 

 on the theory that Heat is a kind of Motion Dr. Mayer sug- 

 gests the Determination of the Mechanical Equivalent of Heat 

 Dr. Joule's Experiments on the Mechanical Equivalent of 

 Heat Dr. Hirn's Experiments on the conversion of Heat into 

 Motion Proof of the Indestructibility and Conservation of 

 Energy Theory of dissipation of Energy Molecular Theory 

 of Gases Free Molecules in Vacuum Tubes . . . 349 



CHAPTER XXXVI. 



SCIENCE OF THE NINETEENTH CENTURY (CONTINUED). 



Oersted discovers the effect of Electricity upon a Magnet 

 Electro-Magnetism Experiments by Ampere on Magnetism 

 and Electricity Ampere's Early Life Direction of the 

 North Pole of the Magnet depends on the course of the 

 Electric Currents Lines of Magnetic Force between two 

 Electric Wires Electro-Magnets made by means of an 

 Electric Current Arago magnetises a Steel Bar with an 

 ordinary Electrical Machine Faraday discovers the Rotatory 

 Movement of Magnets and Electrified Wires Produces an 



