Transcription:
DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEOLOGIC BRANCH Washington, D. C, February 5, 1892. Prof.
John Muir, Martinez, California. My dear Sir: Prof. Ch. Dufour, of the University of Lausanne, Morges, Switzerland, has
recently addressed a letter to the Director of the U. S. Geological Survey, asking for information regarding recent changes
in the glaciers of America. Prof. Dufour's letter has been referred to me, with request that I assemble all available data
bearing on the advance and retreat of the glaciers of this country. As you are more familiar than any one else with the glaciers
of the Sierra Nevada, I wish to ask if you will kindly inform me if they have advanced or retreated since you first became
acquainted with them. I should like also to obtain similar information concerning the glaciers of Alaska. The more definite
this information can be made the better it will be for the purposes in view. Prof. Dufour has published a brochure on the
glaciers of Europe in which it is shown that they are now retreating, and wishes especially to learn if a similar charge is
taking place in the 01552