SECTION II. 



Page 



Chimney Currents 227 



Construction of Chimneys 228 



Chimney-caps 229 



Ventilation 232 



PART IV. 



HEAT. 

 CHAPTER I. 



CONDUCTION OF HEAT. 



SECTION I. 



Conducting Power of Bodies 235 



UtiUty of this Principle 236 



Conducting Power of Liquids 237 



SECTION II. 



Expansion by Heat 238 



The Steam-engine 241 



Exception to Expansion by Heat 246 



SECTION III. 



Latent Heat 248 



Advantages of Latent Heat — Latent Heat of Steam 249 



Green and dry Wood for Fuel 250 



CHAPTER n. 



Radiation of Heat 253 



Dew and Frost 255 



Frost in Valleys — Remarkable Efl'ects of Heat on Water 256 



APPENDIX. 



Apparatus for Experiments 259 



Tables of Specific Gravities 263 



AVeight of a cubic Foot of various Substances 264 



Discharge of Water through Pipes 264 



Velocity of Water in Pipes 265 



Rule for the Discharge of Water 266 



