1813. ] Geological Society. 155 



On the 4 th of June a paper on the Isle of Man, hy J. F. 

 Berger, M.D. was read. The length of the Isle of Man from 

 N. E. to S. W. exceeds 30 miles, and its breadth varies from S 

 to 15 miles. About 5 miles from the north end a mountainous 

 tract begins, runs parallel to the eastern coast, and forms the 

 small island at the south end of the greater, called the Calf of 

 Man. This belt is divided by three tranverse vallies ; two in 

 the larger island, and the third forming the strait that separates 

 the one island from the other. The highest mountains are in the 

 northern division ; and Sneifeldt, the most elevated, is 2000 

 feet above the level of the sea. The rocks of which this country 

 is composed belong chiefly to the transition class of Werner. 

 Small-grained granite occurs in one or two places, and at an 

 elevation of not more than 3 or 400 feet above the level of the 

 sea. Gneiss and mica-slate are wanting, and so are the oldest 

 members of the clay-slate formation. The newest portion of 

 that formation occupies the most elevated parts of the island, 

 where it appears under the form of horn-slate and roofing slate. 

 These rocks pass insensibly to the transition class. The oldest 

 transition rock which appears is grey-wacke. The beds of it are 

 mostly less elevated than those of the clay-slate ; they dip 

 towards the east, and the inclination varies from vertical to about 

 35°. In this formation occur grey-wacke, grey-wacke-slate, and 

 granular quartz slightly micaceous. No organic remains were 

 perceived in any of them. 



The preceding formation is covered by a deposile of lime- 

 stone, less elevated above the level of the sea than the grey- 

 wacke, and approaching more nearly to the horizontal. It 

 consists of beds of shell lime-stone, resembling those of Kilkenny, 

 Westmoreland, Cumberland, and Durham, together with mag- 

 iK'sian lime-stcne, sometimes in beds, but often in patches 

 inclosed within the other. In one or two places the lime-stone 

 is covered by an unstratiricd mass of transition amygdaloid ; the 

 base of which is a greenish wacke, containing nodules of lamellar 

 calcareous spar, invested by a thin coating of iron pvritcs. The 

 only floetz rock that occurs in the island is the oldest sand-stone, 

 sometimes so coarse grained as to merit the name of conglome- 

 rate, in which case it consists chiefly of fragments of quart/, 

 with a few scraps of decayed slate, and a little iron pyrites. The 

 colour of the sand-stone is red, or greyish-white. It is more or 

 llaty, according to the proportion of mica that it contains. 

 It lies unconloiinably over the grey-wacke, and dips N. VV. at an 

 angle varying from 35° to 15°. On the sea shore, and on the 

 lopes of some of the mountains, arc abundant blocks of granite, 

 mica slate, and porphyry. 



The mines in the island, at Loxey, Foxdalc, and Ikada Head 



