Miscellanies. 207 



" The Katakehaumene. — The extent of this interesting tract is much 

 less than is assigned to it in published maps, being not more than 7 

 miles from north to south, and 18 or 19 from east to west. After 

 alluding to his first visit to it in company with Mr. H. E. Strickland, 

 and referring to that gentleman's account of a portion of the district,* 

 Mr. Hamilton describes minutely the two systems of volcanos, distin- 

 guished by the state of preservation of the craters and of the coulees ; 

 he defines also the course of each lava-current, and points out its at- 

 tendant phenomena — but these details admit of only partial abridg- 

 ment. 



" The volcanic products are basalt, lava, and ashes, the first being 

 confined to the more ancient craters, and the last to the more modern. 

 The numerous older cones are further distinguished by being situated 

 on parallel ridges of gneiss and mica slate, and the newer, only three 

 in number, by being confined to the intervening alluvial valleys. 

 This important distinction Mr. Hamilton explains on the supposition, 

 that the elevation of the schistose ridges produced cracks, through 

 which, as points of least resistance, the first eruptions of lava found 

 vent; and that these openings becoming subsequently plugged up, 

 by the cooling of injected molten matter, the schists were rendered 

 so solid, that when the volcanic forces again became active, the lines 

 of least resistance were transferred to the valleys. 



" The coulees from the ancient craters appear to have been partly 

 under water, as their surface is, in some places, covered with sedi- 

 ment and turf; but the lava streams from the modern are bare, rugged, 

 and barren, and the craters are surrounded by mounds of loose 

 scoria; and ashes. In addition to the comparative view given by 

 Mr. Strickland of the phenomena of the Katakekaumene and Central 

 France, Mr. Hamilton enters into a more extended investigation of 

 points of resemblance, including other portions of Asia Minor. The 

 great volcanic groups of Mont Dore, the Cantal, and Mont Mezen, 

 Mr. Hamilton conceives are represented by Ak Dagh, Morad Dagh, 

 the trachytic hills east of Takmak, Hassan Dagh, and Mount Argseus. 

 The modern volcanic period of Central France he compares with the 

 Katakekaumene, as respects the composition of the lavas, their ar- 

 rangement at different levels, and the cones being scattered, not col- 

 lected in great mountain masses. The Katakekaumene, in Mr. Ham- 

 ilton's opinion, exhibits also additional evidence, that the disposition 

 of comparatively recent volcanos is coincident with the strike of the 

 granitic axis, from the interior of which the volcanos have burst forth. 

 The author also alluded to other comparative phenomena noticed in 

 Mr. Strickland's paper. Lastly, he pointed out two distinctions — in 



« See L. & E. Phil. Mag. vol. x, p. 70. 



