CONTENTS. 



CHAP. V. 129. Volcanoes of the Andes Pichincha, Cotopaxi, and 

 Tunguragua. 130. Mexican volcanoes Orizaba, Popocatapetl, 

 Jorullo, and Colima. 181. Singular circumstances attending the 

 elevation of Jorullo. 132. Ancient state of Vesuvius, according to 

 Strabo Eruption of 76 A. D. Destruction of Herculaneum and 

 Pompeii. 133. ^olcano of Kirauea in Owhyhee Mr. Ellis's 

 account of it. 134. Visit of Mr. Stewart and Lord Byron to it 

 in 1825 Mr. Stewart's account of it. 135. Illustrations of the 

 ejection of lava through the strata. 136. .Effect of obstruction 

 Formation of lateral craters. 137. Submarine eruptions 

 Formation of volcanic islands. 138. Volcanic islands off Santorin 

 in the Grecian Archipelago. 139. Phenomena . attending the 

 formation of such islands. 140. Craters of elevation. 141. 

 Stratification around these craters Island of Palma. 142. 

 Formation of islands not necessarily preceded by .eruptions. 

 143. Mount Etna. 144. Historical accounts of its eruptions. 

 145. Eruption of 1832. 146. The Valde Bove. 147. Section 

 and plan of Etna.- 148. Volcanic lakes. 149. Crescent form 

 of volcanic islands. 150. Craters of elevation, temporary and 

 permanent. 151. Barren island in the Bay of Bengal. 152. 

 Traditional volcanic origin of Santorin. "... . . . .97 



CHAP". VI. : 153. Form of craters. 154. Stromboli Formation of 

 internal' adventitious cones and craters. 155. Strata of lava 

 how formed. ; 156. Formation of lava in dykes. 157. Salses, or 

 mud volcanoes. 158. Fumarolles. 159. Geysers. 160. Valleys 

 of .elevation. -161. . Formation of parallel ridges. 362. Slow 

 operation of air, water, and heat. 163. Atmospheric effects upon 

 rocks. 164. Effects of water on rocks, 165. Effects of .the sea 

 on cliffs. 166. Effects of waterfalls. 167. Effects of the sea and 

 of icebergs on the forms of rocks. 168. Geological phenomena 

 explicable by natural causes still in operation. -169. Portland 

 dirt-bed -Its organic deposits. 170. Climate of England tropical 

 at the epoch of these deposits. 171. Example of coal deposits. - 

 172. Northumberland coal mines. 173. Colliery near Wolver- 

 hampton. 174. Deposits in Treuille mine at St. Etienne. 175. 

 The character of the waters shown by the organic deposits 

 Fossil shells . .113 



CHAP. VII. 176. Fossil foraminifera. 177. Fossil infusoria. 

 Researches of Ehrenberg. 178. . Marine deposits at great heights 

 produced by former undulations of the land. 179. Organic de- 

 posits show that the same parts of the land have undergone a 

 series of alternate elevations and depressions. 1 80. Example of 

 the Portland beds. 181. Fossil footsteps. 182. Such, traces 

 common in the new red sandstone, at Hesseburg, and near 

 Liverpool. 183. Footprints of birds. 184. Fossil rain-drops 

 and ripple-marks. 185. Conclusion ..... 129 



THE STEREOSCOPE. 



1. Surprising effect of the instrument explained. 2. Causes of visual 

 perspective and relief. 3. Effects of binocular parallax. 4. 



