CONTENTS OF VOLUME I, 



[NOTE. For Analytical Index, see first Volume.] 



THE PLURALITY OF WORLDS PAGE 49 



Contemplation of the Firmament. Reflections thereby suggested. Limited Powers of the Tele- 

 scope. What it can do for us. Its Effect on the Appearances of -the Planets. Are the Planets 

 inhabited? Circumstantial Evidence. Analogies of the Planets to the Earth. Plan of the Solar 

 System. Uniform Supply of Light and Warmth. Expedient for securing it. Different Dis- 

 tances of the Planets do not necessarily infer different Temperatures, nor different Degrees of 

 Light. Admirable Adaptation of the Rotation of the Earth to the Organization of its Inhabitants. 

 The same Provision exists on the Planets. Minor and Major Planets. Short Days on the lat- 

 ter. The Seasons. Similar Arrangement on the Planets. The Atmosphere. Similar Append- 

 age to the Planets. Many Uses of the Atmosphere. Clouds. Rain, Hail, and Snow. Mountains 

 on the Planets. Land and Water. Weights of Bodies on the Planets analogous to Weight on 

 the Earth. Appearances of the Sun. Conclusion. 



THE SUN 65 



The most interesting Object in the Firmament. Its Distance. How measured. Its Magnitude. 

 How ascertained. Its Bulk and Weight. Its Density. Form. Time of Rotation. Spots. 

 Its Physical Constitution. Nature of the Spots. Luminous Coating. Its Thickness. Probable 

 Temperature of the Surface of the Sun. Nature of its Luminous Matter. 



ECLIPSES 77 



Lunar and Solar Eclipses. Their Causes. Shadow of the Earth. Shadow of the Moon. Mag- 

 nitude of Eclipses. When they can happen. Central Solar Eclipse. Great Solar Eclipse 

 described by Halley. Ecliptic Limits. 



THE AURORA BOREALIS ,.. 87 



Origin of the Name. Produced by Electricity. General Phenomena of Auroras. Various Exam- 

 ples of this Meteor. Biot's Excursion to the Shetland Isles to observe the Aurora. Lottin's 

 Observations in 1838-'39. Various Auroras seen by him. Theory of Biot to explain these 

 Meteors. Objections to it. Hypothesis of Faraday. Auroras seen on the Polar Voyage of 

 Captain Franklii. 



ELECTRICITY 101 



Electric Phenomena observed by the Ancients. Thales. Gilbert de Magnete. Otto Guericke's 

 Electric Machine. Hawkesbee's Experiments. Stephen Grey's Discoveries on Electrics and 

 Non-Electrics. Wheeler and Grey's Experiments. Dufaye discovers the Resinous and Vitreous 

 Electricities. Invention of the Leyden Phial Singular Effects of the first Electric Shocks. 

 Experiments of Watson and Bevis. Experiments on Conductors. Franklin's Experiments and 

 Letters. His celebrated Theory of Positive and Negative Electricity. His Experiments on the 

 Leyden Phial. His Discovery of the Identity of Lightning and Electricity. Reception of his 

 Suggestions by the Royal Society. His Kite Experiment. His Right to this Discovery denied 

 by Arago. His Claim vindicated. Invention of Conductors. Death of Richmann. Beccaria's 

 Observations. Canton's Experiments. Discovery of Induction. Invention of the Condenser. 

 Works of ^Epinus. Theory of Symmer. Experiments of Coulomb. Balance of Torsion. 

 Electricity of the Atmosphere. Effects of Flame. Experiments of Volta. Lavoisier and La- 

 place. Analytical Work of Poisson. 



