86 
GEOLOGV 
not been geologically drawn at the time of Lyell’s publication. These additions are principally 
due to David Dale Owen for the Upper Mississippi from S‘ Louis to Lake Winipeg, Ferdinand 
Roemer for Texas, M. Tuomey for Alabama, O.M.Lieber for tbe State of Mississippi, Safl'ord for Ten- 
nessee, G.C. Swallow for Missouri, Charles T. Jackson for the southern part of Lake Superior, and 
J. W. Dawson for the British Provinces. Further, my friend Dr. Charles T. Jackson permitted me 
to use his manuscript geological map of the State of Maine, and Prof. J. F. Frazer showed me one of a 
considerable part of Pennsylvania. I have also had the use of manuscript notes upon Newfound- 
land, Cape Breton Island, Hudson Bay Territory, Lower Canada, Kentucky, Tennessee, Florida, 
Louisiana, the Osage Indian Country, Chihuahua, Sonora, Arizona, Utah, the vicinity of Forts 
Laramie and S‘ Vrain, Oregon, and Vancouver Island, that were given to me hy travelling geo- 
logists, or officers of the Army and Navy, with full liberty to employ them as I pleased. I am 
especially grateful to Richard Brown, superintendent of the Coal mines of North Sydney, Cape Bre- 
ton; J. W. Dawson, formerly of Pictou, now Principal of M° Gill College, Montreal; Admiral, 
Earl of Dundonald , Commander in Chief of the British North American squadron in 1849 ; Dr. Charles 
T. Jackson of Boston; Isaac Lea of Philadelphia; Dr. Charles Girard, the celebrated zoologist of 
Washington, my old friend and fellow student in the house of Prof. Agassiz, and until lately one of tbe 
most useful attaches of the Smithsonian Institution; Dr. Samuel Royal of the vicinity ofRichmond, Virginia; 
Dr. L. P. Yandell of Louisville; John Gebhard Jr. of Schoharie, New York; Prof. Eben. Emmons 
of Albany; Prof. J. M. Salford of Lebanon, Tennessee; Dr. Geo. G. Shumard of Fort Smith, Arkan- 
sas; Capt. A. W. Whipple, Corps Top. Engrs. U. S. A., who during a campaign of ten months 
in the Rocky Mountains was my constant companion, and is one of my most valued friends ; Capt. 
John Pope of the same Corps; Capt. W. Swift, an old pupil of General Bernard, and one of the com- 
panions of Major S. H. Long in his Rocky Mountain exploration', Major J. H. Carleton of the 1' Dra- 
goons U. S. A.; Colonel W. C. Grant of Soke Harbor, Vancouver Island; the late Dr. Randall 
of Monterey, California; the celebrated French botanist A. Trecul, my friend and travelling com- 
panion in 1848; and lastly my friend, Antoine Leroux of Taos, the best of the Guides in the 
Rocky Mountains. 
I have travelled myself for seven years in the following countries, for the purpose of making 
geological observations; Cape Breton Island, Nova Scotia, New Brunswick, the New England 
States , Upper and Lower Canada , made the complete tour of Lake Superior and a part of the road 
between Lake Superior and Lake Winipeg; the States of New York, New Jersey, Pennsylvania, 
Maryland, Virginia, Kentucky, Ohio, Michigan, Indiana, Illinois, Wisconsin, Missouri, Tennessee, 
Arkansas, Texas; the Cherokee and Choctaw countries; New Mexico, and California. So that, 
if two thirds of this map is only a compilation from the labors of others, the other third was made 
from my own observations, and I think, I may say truly, that at the time of its publication in 1855, 
I had seen more of North America than any other living geologist either of America or Europe. 
Having crossed hy land the whole Continent from the Coal mines of Sydney, Cape Breton, to the 
gold diggings of the Sacramento , it is evident I could not devote myself to the study of minute de- 
tails, as those geologists do who remain stationary at one point; and the map should not be judged 
by the details , but the ensemble ; and I will say of it as de Saussure said of mountains , « qu'elles ne 
doivent pas ^tre observe'es avec m microscopes. 
