CONTENTS. It, 



CHAPTER XVI. 



BOUND. 



Difficult problem in Science. Prof. Tyndall's explanation not satisfactory. 

 Sound vibrations and light vibrations. Sound generates heat. 

 How long fifty organs would take to heut St. Paul's Cathedral. 

 Sound in summer and winter. How we hear fifty sounds at the 

 same time. Echoes. New theory of Sound. A sympathy between 

 the mineral atoms of matter. Iron a better conductor than wood. 

 If a man has sympathy why should not an atom ? Dancing flames. 

 Tyndall's new theory of Sound. Experiments at the South 

 Foreland, England. Vapour in layers 102 106 



CHAPTER XVII. 



W AT B K AND RAIN. 



Fire not so powerful as water. 'Water in granite Herschell on Rain. 

 Rain caused by chemical action in the atmosphere. The Rain 

 guage. Rain forms in the lower atmosphere. Proctor and Kamtz 

 on the reason why. Rain shot out from clouds. Ilerschell on Rain 

 storms. Climate of North America changing. Egypt cultivating 

 the Palm for Rain. Forests and vegetation cause Rain. Herehell's 

 reason why, a failure. Drainage said to be, bad.Chicago, St. 

 I/mis, once unhealthy. Why. No large city unhealthy. No air 

 in water. Fishes gills used for filtering food, not for breathing. > 

 The air they need produced from digestion. Can we produce or 

 bring down Rain 1 Great battles in America were followed by 

 Rain. The cause. 107 1 12. 



CHAPTER XVIII. 



Chambers Journal. Baptista Porta nearly discovered the true theory of 

 dew. Thought dew was condensed from air. Aristotle thought it 

 was condensed from vapour. Muschenbrook kept back Meteorology 

 mMhhundred years. Great discoveries often foiled by the stupidity 

 of the world. Dr. Wells said to be the discoverer of the true dew 

 theory. The radiation of heat, the basis. The cause of moonblind- 

 ness. Dew forms most readily on vegetation. Arguments against 

 radiation. Observations with wool packs. Position everything. 

 Calm and clear evenings essential. Dew is water. Produced in a 

 similar way. The cause of fog and hoar frost. Hoar frost spears 

 of ice 11 91 23. 



CHAPTER XIX. 



THE ATJCOSPHEFE AND STORMS. 



Atmosphere said to be composed of oxygen and nitrogen. An impossibility. 

 Air in no two places the same. Balloon explorations. Guy 

 Lussac. Everything with life has an atmosphere. The atmosphere 

 of the African. Impossible to get rid of it The earth a living 

 body. Has an Atmosphere composed of its own materials. The 



