on the Liverpool and Manchester Railway. 387 



this reason, it appears to nie that very great velocities are incom- 

 patible with supplying the means of conveyance to places inter- 

 mediate between the coke and water stations, unless we can con- 

 trive some means of letting off the passengers without stopping 

 the whole train. This could be accomplished by placing all 

 those destined for a particular place in one carriage, and allow- 

 ing that to fall off from the train half a mile or quarter of a 

 mile before arrival ; but then there would be the annoyance of 

 gathering up these stray waggons, while no means would be 

 afforded of taking up passengers. 



This subject will undoubtedly become important when greater 

 extent of rails is laid down, and greater rapidity aspired at, 

 but in the present state of matters, the expedient of having a 

 first class train to go straight through, and a second class train 

 to stop at intervals, seems to answer every required end. 



Theory of Granite, and the other Massive Rocks ; together with 

 that ()f Crystalline Slate]; proposed in Lectures in Geology, in 

 the University of Christiania in Norway, in the year 1836. 

 By B. M. Keilhau, Professor of Mineralogy.* 



(First Extract.) 

 Having described in a general way the stratified rocks of the 

 younger transition series,-]- we must now, according to our usual 

 method, inquire if massive (" abnormal") rocks also occur 

 within the limits of that formation, and proceed to treat of them 

 in the same general manner. We shall first describe the con- 

 stitution of this group in Norway, as it is precisely here that 

 these formations ai-e presented to us in the most instructive 

 manner, and are so exhibited as to afford illustrations by which 

 we may more easily rise to general considerations. The clear- 

 ness of the geological relations of the above-mentioned rocks in 

 our country is so great, that their study will, I hope, lead us to 



* This interesting memoir is translated from an article in Danish, in the 

 first Number of the " Nyt Magazin for Naturvidenskaberne,'^ recently com- 

 menced at Christiania. We are indebted for a separate copy of the essay to 

 the kindness of its distinguished author. 



t I divide the transition class into two groups, a younger, rioh in limestone 

 and petrifactions ; and an older, comprehending especially sandstones, and 

 which never, or at least very rarely, contains fossils. 



