XIV. 



CONTENTS. 



Human body cannot always distinguish temperature 



accurately, . . . . . 283 



Table of temperatures, . . ... 283 



Specific heat, . . . . . 285 



Latent heat of fluidity, . . . . 285 



Latent heat of vaporisation, .... 286 



Freezing and chilling machines, . . . 287 



RADIANT ACTION. VISIBLE LIGHT, .... 288-349 



CHAPTER XXII. Emission of Visible light. Illumination 

 of Objects not self -luminous. Colour and Absorption. 

 Reflection and Refraction at Plane Surfaces, . . 288-331 



Sources of light, natural and artificial, . . . 288 



Brilliancy and colour, ..... 290 



Emission and scattering of light : emission colours, . 291 



Transparency and opacity : absorption, . . . 292 



Laws of reflection and refraction : illustrations, . 293 

 Absorption of light to varying extents : absorption 



colours, ...... 296 



Total internal reflection, . . . . . 298 



Critical angle, . . . . . . 299 



"Wollaston's camera lucida, .... 300 



Amici's do., ..... 301 



Mirage, ....... 301 



Pepper's Ghost, ...... 303 



Illusion of the " Bodyless Lady" or "talking head," . 305 



Wizards' mirrors, . .. .... 307 



Double image formed by ordinary looking glass, . 308 



Kaleidoscope, ...... 309 



Endless gallery, . . . . . . 311 



How to see through a brick wall, . . . 312 



Displacement of images by plates and prisms, . . 312 



Colour spectrum : combination of colours, . . 314 



Newton's colour disc, . . . . 316 



Chromatropes and colour tops, . . . . 317 



Thaumatropes and zoetropes, ,<>. . . . 317 



Complementary colours, . '%. 319 



Spectroscope, . . . . .." 321 



Stereoscopes, ...... 321 



Pseudoscope, ...... 323 



Various illusions : Zb'llner's lines : black and white 



circles : chequers : Aristotle's experiment, . . 326 



