8 
INTRODUCTION. 
sociation for the year 1854 (see: Silliman’s Journal of Science, vol. XXII., second series, Nov., 
1856.), and in the text of a « Geological Map of the United States and British North American, by Henry 
D. Rogers, where there is a paragraph entitled: History and Literature of geological research in the 
United States’, 1 thought it would be more just to those who made these discoveries, to cite from 
their own works , giving the official date of their publications , so that each one may be able to judge 
for himself of the truth and value of these discoveries. To this end I have given a Chapter en- 
titled : A synopsis of the Progress and Discovery of Geology in America , in which I have placed quotations 
taken from all the official sources to which I have had access ; and if I have not been able to give 
exact dates, I have at least made every effort to do so, notwithstanding the difficulty created by 
my temporary absence from the United States , and my actual residence in a small town of German 
Switzerland. 
Urged by the same motive of rendering justice to the geologists who have contributed tbe most 
to the progress of American geology, I have added a list of general geological maps, giving at 
the commencement a reprint of the 6rst memoir of Maclure, with map; a work now very rare 
and almost impossible to obtain. 
To this is added a list of books consulted for the completion of this work, and the translation 
of two memoirs published in French; On the Gold of California (See: Bibliotheque Universelle de 
Gendve, Fevrier 1855; Sur le Gisement de Vor en Californie.')', and the Systems of Mountains in a part 
of North America (See: Annales des Mines, tome \TI. , 1855; Esquisse dune classification des chaines de 
montagnes dune partie de I'Amerique du Nord,^. 
ZURICH (Switzerland), September the 25'^ 1857. 
