CONTENTS 



CHAPTER VI 



MODERN THEORIES OF HEAT AND LIGHT 



Josiah Wedgwood and the clay pyrometer, p. 206 Count Rumford 

 and the vibratory theory of heat, p. 208 His experiments with 

 boring cannon to determine the nature of heat, p. 209 Causing 

 water to boil by the friction of the borer, p. 213 His final deter- 

 mination that heat is a form of motion, p. 215 Thomas Young 

 and the wave theory of light, p. 215 His paper on the theory of 

 light and colors, p. 217 His exposition of the colors of thin plates, 

 p. 218 Of the colors of thick plates, and of striated surfaces, p. 

 219 Arago and Fresnel champion the wave theory, p. 225 Oppo- 

 sition to the theory by Biot, p. 226 The French Academy's tacit 

 acceptance of the correctness of the theory by its admission of Fres- 

 nel as a member, p. 227. 



CHAPTER VII 



THE MODERN DEVELOPMENT OF ELECTRICITY AND MAGNETISM 



Galvani and the beginning of modern electricity, p. 229 The con- 

 struction of the voltaic pile, p. 230 Nicholson's and Carlisle's dis- 

 covery that the galvanic current decomposes water, p. 232 De- 

 composition of various substances by Sir Humphry Davy, p. 233 

 His construction of an arc-light, p. 234 The deflection of the mag- 

 netic needle by electricity demonstrated by Oersted, p. 237 Ef- 

 fect of this important discovery, p. 238 Ampere creates the science 

 of electro-dynamics, p. 239 Joseph Henry's studies of electro- 

 magnets, p. 239 Michael Faraday begins his studies of electro- 

 magnetic induction, p. 240 His famous paper before the Royal 

 Society, in 1831, in which he demonstrates electro-magnetic induc- 

 tion, p. 241 His explanation of Arago 's rotating disk, p. 244 The 

 search for a satisfactory method of storing electricity, p. 247 

 Roentgen rays, or X-rays, p. 247. 



CHAPTER VIII 



THE CONSERVATION OF ENERGY 



Faraday narrowly misses the discovery of the doctrine of conserva- 

 tion, p. 253 Carnot's belief that a definite quantity of work can 

 be transformed into a definite quantity of heat, p. 255 The work 

 of James Prescott Joule, p. 256 Investigations begun by Dr. 

 Mayer, p. 257 Mayer's paper of 1842, p. 259 His statement of the 



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