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 Eartb. — 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 Franklin. 



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-Electric3. — 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 iEpinus. — 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. 



