Vlll GENERAL SUMMARY 



The Moon of the Earth ; produces light and heat ; ash-gray 

 or earth-light in the Moon ; spots ; nature of the Moon's 

 surface, mountains and plains, measured elevations ; pre- 

 vailing type of circular configuration ; craters of elevation 

 without continuing eruptive phenomena ; old traces of 

 the reaction of the interior upon the exterior (the sur- 

 face) ; absence of Sun and Earth tides, as well of current* 

 as transportive forces, on account of the want of a liquid 

 element ; probable geognostic consequences of these re- 

 lations — p. 141-159. 



Mars ; ellipticity ; appearances of surface altered by change 

 of the seasons — p. 159, 160. 



The small planets — p. 161, 162. 



Jupiter : periods of rotation ; spots and belts — p. 165-168. 

 Satellites of Jupiter — p. 169, 170. 



Saturn : bands, rings, eccentric position — p. 170-174. 

 Satellites of Saturn — p. 174, 175. 



Uranus — p. 175, 176. 



Satellites of Uranus — p. 176, 177. 

 Neptune: discovery and elements — p. 177-181. 



Satellites of Neptune — p. 181-201. 



III. The Comets : with the smallest masses occupying immense 

 spaces ; configuration ; periods of revolution ; separation ; elements of 

 the interior comets — p. 181-201. 



IV. The ring of the zodiacal light : Historical particulars. Intermit- 

 tence two-fold ; hourly and annual ? Distinction to be made between 

 the cosmical luminous process which belongs to the zodiacal light it- 

 self and the variable transparency of our atmosphere. Importance of a 

 long series of corresponding observations under the tropics at different 

 elevations above the sea from 9 to 12,000 feet. Reflection like that at 

 sunset. Comparison in the same night with certain partsrf>f the Milky 

 Way. Question as to whether the zodiacal light coincides with the 

 plane of the Sun's equator — p. 201-204. 



V. Shooting stars, fire-balls, meteoric stones : Oldest positively determ- 

 ined fall of aerolites, and the influence which the fall of /Egos Potamos 

 and its cosmical explanations exercised upon the theories of the uni- 

 verse of Anaxagoras and Diogenes of Apollonia (of the later Ionic 

 school); force of revolution which counteracts the power of the fall 

 (centrifugal force and gravitation) — p. 204-209, note ], p. 207, and p. 

 209, note *. Geometric and physical relations of meteors in sporadic 

 and periodic falls; divergence of the shooting stars; definite points of 

 departure ; mean number of sporadic and periodic shooting stars in an 

 hour in different months — p. 209-214, note \, p. 210, and p. 211, note *. 

 Besides the stream of St. Laurentius, and the now more feeble Novem- 

 ber phenomenon, four or five other falls of shooting stars have been 

 discovered which very probably occur periodically during the year — 

 p. 214, note *, p. 215, and p. 216, note *. Height and velocity of the 

 meteors — p. 217. Physical relations, color and tails, process of com- 

 bination, magnitudes; instances of the firing of buildings — p. 217. Me- 

 teoric stones; falls of aerolites when the sky is clear, or after the for- 

 mation of a small dark meteoric cloud — p. 220, note +, and p. 221. note *. 



