LETTER OF TRANSMITTAL. 



Department of the Interior, 

 United States Geological Survey, 

 Section of Pre-Cambrian and Metamorphic Geology, 



Madison, Wis., April 30, 1903. 



Sir: I transmit herewith the manuscript of a treatise on metamorphism, 

 to be published as a monograph. 



This treatise is an attempt to reduce the phenomena of metamorphism 

 to order under the principles of physics and chemistry, or, more simpl}', 

 under the laws of energy. The first nine chapters treat of metamorphism ; 

 the last three chapters, of the relations of metamorphism to stratigraphy, 

 to the redistribution of the elements, and to ore deposits. 



In the preparation of this monograph I have had important assistance 

 from various sources. The late Prof. George H. Williams, of Johns 

 Hopkins University, before his death had begun to accumulate material 

 and notes upon metamorphism. He had made a careful abstract of the 

 most important literature on the subject; also a draft, consisting of about 

 twenty pages of manuscript, of a first chapter. All of this material 

 Mrs. Williams turned over to me. The summary of literature prepared 

 by Dr. Williams has been of very great service. To this dear friend, the 

 first great teacher of petrology in this country, I dedicate this volume. 



In the actual preparation of the manuscript I have had the assistance 

 of a number of men, and of a considerable number of advanced students. 

 In the earlier work Dr. C. K. Leith aided me much by looking up and 

 summarizing literature and by offering many valuable suggestions. Later 

 Mr. W. N. Smith continued this work. To the discriminating judgment of 

 Dr. Leith and Mr. Smith I am greatly indebted. Mr. A. T. Lincoln has 

 made all the numerical computations in reference to the volume relations of 

 original and secondary minerals, and Mr. R. M. Chapman has verified Mr. 

 Lincoln's work. While these are the men who have assisted me most, a 

 number of graduate students, both at the University of Wisconsin and at 

 the University of Chicago, have helped in various ways. 



