14 Dr. Forchhammer on the ' [July, 



I have also found that the temperature of a working spot in 

 Huel Abraham, at the 180 fathom level, where the difference of 

 atmospheric pressure was 0*964, or nearly one inch, when 

 other circumstances, such as number of men, current, blasting 

 of rocks, &c. &c. were similar, that the difference of temperature 

 was only from U^° to 2°; it bein^ 78° when the thermometer 

 was lowest, and 79^^° to 80° when highest. 



If these remarks appear to contain any further necessary infor- 

 mation respecting the temperature of our mines, in continuation 

 with what has already appeared, your inserting them in the 

 Annahy will much oblige your humble servant, 



M. P. MOYLE. 



Article IV. 



On the Transition Formation of Sweden. By Dr. Forchhammer. 



(To the Editor of the Annals of Fhilosophy.) 



DEAR SIR, 

 The curious facts respecting the transition formation of 

 Norway, which were discovered nearly at the same time by two 

 German geologists, MM. Von Buch and Hausmann, have 

 excited a great degree of interest, and although much which 

 was at first supposed to be peculiar to the mountains of Scandi- 

 navia, has been found in other countries ; and much which was 

 imagined to be an exception, appears now to lie within the rule; 

 yet enough remains to distinguish this formation from all others, 

 and to show that the chemical power, which acted so strongly 

 in the formation of the primitive rocks of the north, exerted its 

 influence equally on the transition formation. It ought not to 

 be forgotten, that a long time before the geologists now men- 

 tioned made their discoveries, Hissinger had made known a 

 number of facts on this formation, with regard to Sweden, and 

 several writers of minor note in respect to Norway ; but the 

 most interesting had not been observed, and the rest had not 

 been connected in such a way, as to give any precise idea about 

 the relative age of these formations, so as to compare them with 

 those of other countries. The German geologists found, that 

 porphyry, syenite, granite, in the neighbourhood of Christiania, 

 rested on limestone and slate, and, while the first rocks con- 

 tained zircon, feldspar, hornblende, paranthine, epidote, beryl, 

 molybden, the others contained the fossils of marine animals. 

 With respect to Sweden, M. Hausmann has given some very in- 

 teresting notices, principally about the transition trap of West- 

 l^othland, and the transition porphyry of Dalerne. A few years 



