480 APPENDIX. 



this subject: still destined, undoubtedly, to do mueli 

 more, when the nature of the earths becomes better 

 known, and when geologists shall be convinced, that 

 without such knowledge, the teacher can as little 

 deserve as he can claim attention. If there is any 

 species of ignorance by which geology has hitherto 

 been peculiarly obstructed, it has been by ignorance 

 of chemistry. But it is neither needful nor possible 

 to be a Berzeiius ; as it is not also a mere familiarity 

 with details that will render the geologist what he 

 ought to be in this science, but the command of gene- 

 ral principles, with a readiness and power in applying 

 them to new facts, and in disentangling complicated 

 appearances. 



Scarcely less folly has arisen from the want of ma- 

 thematical knowledge among geological theorists ; 

 though I need make no remarks on that which is ad- 

 mitted to be indispensible to a scientific education. 

 But omitting higher considerations, the geologist ought 

 at least to be versed in plane trigonometry, and even 

 to possess practical facility in all the ordinary opera- 

 tions of measuring ; since they may often become 

 necessary to the accuracy and verification of his 

 work, as geographical errors may often materially im- 

 pede liis own deductions. Here let me also note the 

 necessity of cultivating a geographical eye ; that tact 

 which, in different ways, distinguishes the military 

 commander and the American savage; almost seeming 

 in the latter, the result of some mysterious sense, as in 

 the migratory birds. It is through this talent that the 

 possessor immediately feels his situation in the most 

 intricate country ; recognizing even mountains and 

 other objects, in positions before unseen, tracing their 

 dependencies, estimating their distances, and even ap- 

 proximating to their elevations. Thus indeed only 



