522 Scientific Geology. 



16. Bed Mag. Ox. of Iron, 



Bernardston, North and South 20 S. E. 



17. Bed of Plumbago, Sturbridge, N. 30 E. 60to 70 N. W 



18. Do. Iron and Zinc, 



Sterling, N. several degrees East. Do. 



19. Vein of Lead, Hatfield, Nearly N. W. and S. E. Vertical ? 



Regarding only the veins in the above table, and judging merely 

 from their course, we should infer that all of them were produced at 

 two epochs, except the single vein in Hatfield. But the great differ- 

 ence between the age of the new red sandstone, containing the copper 

 veins, and that of the granite and mica slate containing the other 

 veins, renders it probable that those in the former rock must have 

 been formed at a different epoch from those of the latter. On this view 

 of the subject we must refer these veins to four periods : 1. The veins 

 of copper 5 & 6, in the new red sandstone : 2 The veins of lead, 4 and 

 5: 3. The veins 8, 9, 10, 11, 12, 13 and 14: 4. The vein 19. If the 

 beds be considered as connected in their origin with the veins, the 

 number of epochs of production will not be increased: Since the beds 

 I, 2, and 3 will belong to the first epoch, and 15, 16, 17 and 18, to 

 the second. 



2. Elevation of the Mountains and Systems of Strata in Massachu- 

 setts. 



Geologists who saw that the existing continents of the globe had 

 obviously been raised from the bottom of the ocean, had sometimes 

 suggested that different mountain ridges had been lifted up at differ- 

 ent epochs. And they seemed to approach very near sometimes to 

 the discovery of the principle by -which they could determine the 

 relative ages of these mountains. But it was reserved for Eli de Beau- 

 mont to develope the true principles by which we should be guided in 

 such investigations : and perhaps no discovery in geology within the 

 present century, has excited so much interest among geologists as 

 this. I could not, therefore, be justified in closing my report without 

 an effort to apply these principles to the mountains and systems of 

 strata in Massachusetts. But as no effort of the kind has been made 

 in this country, I fear that I shall make but a feeble beginning. 



