s--Ashen Light--Solidity of
the Earth--Variation of Latitude--Secular Changes of Climate--Figure
of the Globe--Study of the Moon's Surface--Lunar Atmosphere--New
Craters--Thermal Energy of Moonlight--Tidal Friction 243

CHAPTER VIII

PLANETS AND SATELLITES--(_continued_)

Analogy between Mars and the Earth--Martian Snowcaps, Seas, and
Continents--Climate and Atmosphere--Schiaparelli's Canals--Discovery
of Two Martian Satellites--Photographic Detection of Minor
Planets--Orbit of Eros--Distribution of the Minor Planets--Their
Collective Mass and Estimated Diameters--Condition of Jupiter--His
Spectrum--Transits of his Satellites--Discovery of a Fifth
Satellite--The Great Red Spot--Constitution of Saturn's Rings--Period
of Rotation of the Planet--Variability of Japetus--Equatorial Markings
on Uranus--His Spectrum--Rotation of Neptune--Trans-Neptunian
Planets 274

CHAPTER IX

THEORIES OF PLANETARY EVOLUTION

Origin of the World according to Kant--Laplace's Nebular
Hypothesis--Maintenance of the Sun's Heat--Meteoric
Hypothesis--Radiation as an Effect of Contraction--Regenerative
Theory--Faye's Scheme of Planetary Development--Origin of the
Moon--Effects of Tidal Friction 308

CHAPTER X

RECENT COMETS

Donati's Comet--The Earth again Involved in a Comet's Tail--Comets of
the August and November Meteors--Star Showers--Comets and
Meteors--Biela's Comet and the Andromedes--Holmes's Comet--Deflection
of the Leonids--Orbits of Meteorites--Meteors with Stationary
Radiants--Spectroscopic Analysis of Cometary Light--Comet of
1901--Coggia's Comet 323

CHAPTER XI

RECENT COMETS--(_continued_)

Forms of Comets' Tails--Electrical Repulsion--Bredikhine's Three
Types--Great Southern Comet--Supposed Previous Appearances--Tebbutt's
Comet and the Comet of 1807--Successful Photographs--Schaeberle's
Comet--Comet Wells--Sodium Blaze in Spectrum--Great Comet of
1882--Transit across the Sun--Relation to Comets of 1843 and
1880--Cometary Systems--Spectral Changes in Comet of 1882--Brooks's