98 GEOLOGY OF NORTH AMERICA. 
anonymous, according to his usual custom. Besides I should he wrong to complain; he has treated 
far better geologists than I am, in the same manner, and his conduct toward Sir Charles Lyell, 
Professor Eh. Emmons, and other geological celebrities, is well known in the scientific world. 
In giving the above criticisms at length, I have had in view rather to show the varying opi- 
nions upon difficult questions in American geology, than the good taste and literary capabilities of 
my adversaries. The ill humour of Messrs. Hall ifc Co. is of little import as to the advance of 
geology , but I am glad to see these savants give quite decided opiuions , diametrically opposed to 
mine, upon several questions relative to the age of the strata of some formations, at Lake Supe- 
rior, in Virginia, the Prairies, Texas, the Rocky Mountains, etc. 
This will enable the geologists who study these questions to decide between us; and if I have 
not succeeded in my determination of the rocks that I regard as New Red Sandstone, Jurassic, Neo- 
comian, and White Chalk, I can only say that I have tried my best to do my duty as a travelling- 
geologist. 
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