114 CORRESPONDENCE. 



6. Craters and currents, and various ejections of extinct Vol- 

 canoes. 



7. Volcanic Islands that have risen from the sea ; how long in 

 rising ; with or without permanent convulsions ; period in which 



they arose. 



- 



Geology, Mineralogy, fyc. 



1 . Geological specimens and minerals of every variety. 



2. Inclination of strata ; dip, direction, and thicknes. 



8. Succession of strata and order of superposition. 



4. Situation of fossiliferous strata in relation to the sea, lakes, 

 and rivers. 



5. Granite veins, or veins of other rocks, with their intrusions. 



6. Fossiliferous rocks ; in every case whether covered by 

 igneous rocks ; if not, by what rocks ? 



7. Trap rocks ; position ; intrusion among other rocks ; altera- 

 tions produced by their contact. 



8. Mountains, their height and form ; on the coast or islands ; 

 in groups or single. 



9. Elevation of coasts, as indicated by shells adhering to rocky 

 shores, by waving water lines in the rocks ; amount of elevation ; 

 testimony of inhabitants as to the time in which it took place ; sub- 

 sidence of coasts, islands, structures, &c., and the proof of the fact. 



10. Coral reef islands ; above or under water. 



1 1 . Ice Islands, magnitude ; depth ; motion ; in groups, or 

 single ; temperature of air upon approaching them ; and of the 

 water surrounding them, whether transporting rocks or stones, and 

 the lowest latitude in which they are seen. 



" 2. Surface rocks of every country ; that is, rocks in situ. 



Magnetism, Electricity, <c, 

 1 . Magnetism ; dip and variation of the needle. 



