YUl GENERAL SUMMARY 



The Moon of the Earth ; produces light and heat ; a^h-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 currenti 

 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— -g. 181-201. 



III. The Comets : with the smallest masses occupying immense 

 spaces; configuration; periods of I'evolution ; 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 wilh certain parts of 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, f re-balls, meteoric stones : Oldest positively determ 

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

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

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

 school) ; force of revolution which counteracts the pc wer of the fall 

 (centrifugal force and gravitation) — p. 204-209, note i, 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 X, 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. 21C, 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 t, and p. 221, note * 



